# Octane Booster



## Jez (Oct 8, 2001)

Guys,

I know this has been covered before but as the search function doesn't work I can't find the old threads covering this.

I'm trying to find out which is the best Octane Booster to use.
I am going to Le Mans in June and am unsure how good the fuel is in France and what I should be using.

Anyone know a good Octane booster and what RON the fuel is in France.

Cost is not so important, I just want the one that will give the most poke :smokin: (and least det  )

I'm sure I saw Ian SuttoN1 flogging bottles of something at the Grasshopper.
Got any left ?

Jez


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## Philip (Jan 17, 2002)

Plenty of 98 RON in France. Is this the stuff you're thinking of - http://www.nitrous-formula.com ?

Phil


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## Jez (Oct 8, 2001)

Philip,

Thanks,

that's the kind of stuff I am looking for.

Also how is the fuel labelled in France, i.e what is french for normal and Super ( I presume super is 98 RON ).

Look forward to having a few beers in France.

Jez


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## Smootster73 (Oct 23, 2001)

*Jez*

I can get hold of some millers stuff from the 200+ club.
I have been meaning to get some if you want to share a box load.
Send me a pm mate or give me a shout.

Nick


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## Scott J Davies (Oct 10, 2001)

Hi Jez

The Stuff that Ian was selling is NF IMHO it is the best I have tired 5 other types it is the only one where I have truely FELT a difference. It apparently cam out tops on independent tests.

Try it!!

SJD


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## keith (Jun 29, 2001)

*MILLARS CVL IS THE BEST*

--------------------------------------------------------------------------------
THOUGHT I WOULD POST THIS AGAIN SO THAT EVERYONE 
CAN SEE IT


well i spoke to the chemist guy from millars today
and he told me if i was to use the CVL with our 97 super plus
it takes it up a full 3 points =100 octane fuel

the only thing it is more money to buy and
it only does 20L instead of 40L 

cant wait till the optimax comes to aberdeen 
98.6 + CVL = 101.6 THE POODLES NOODLES

THE VSP AND THE OCTANE PLUS ARE OK BUT NOTHING 
LIKE THE CVL 
£4.00 PER BOTTLE

KEITH


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## TOKYO (Jun 28, 2001)

*Millars*

Yep agree.

Don't go too fast Jez or people won't be able to see your rims properly  .

glen


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## Rupert (Jun 28, 2001)

*Demon Tweaks*

These guys do a good brew in a can. It's around £7 a pop and one can does 2 tank fulls. You can buy it on line and get it delivered right to your door for free.

It's called:

Silkolene Octane Pro-Boost.

Rupert


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## Mycroft (Apr 13, 2002)

*Don't bite me please.*

This Millars stuff, is it a 'real' octane booster or a 'Knock sensor fooler'

I ask because here at the Institute we have conducted a lot of tests on 'Octane enhancers' Not one actually does 'what it says on the can' except by only the thinnest of margins. The best result was an improvement of 0.59 of an octane. (about the same as the pump tolerance)

What we did find was that the 'better' ones changed the properties of the 'knock' and this fooled the engines sensors into thinking all was OK.

We found the only viable (and not very at that) alternative was Toluene, mixed at 9 parts pump fuel 1 part Toluene, this gave about 4% increase in power at the flywheel, across the rev range.

Could you point me in the direction of the formula or something similar?


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## alex h (Mar 11, 2002)

Anything in a bottle smaller than a can of coke can't really do anything for your octane rating IMO.

Toluene...is THE way of boosting Octane 10:1 mix is what I've been recommended but it depends on how good your ECU is at adapting to it.

Proboost and Millers just can't compare....only problem is that Toluene is not allowed to be bought as fuel. So you just say you want it for thinning paint or degreasing. Try Albion Chemicals...I think they are nationaly based...they took over Hays Chemicals.

Its cheaper than Fuel! I bought 75L for about £45...I think...I have family in the trade...it always helps!!


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## Scott J Davies (Oct 10, 2001)

Have used Millers and Silkolene and many others. NF is the only product where I have felt results. 

In an independent test of 10 boosters it came out on top, it can give up to 6 ron at only 15mls per litre. 

Take a Pepsi challenge, trust me you won't be disappointed.

Oh and I don't sell this either etc, just my experience. NOS make a booster which is meant to be pretty tasty as well.

SJD


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## Fuggles (Jul 3, 2001)

Don't forget, if you leave fuel in the tank for a few days it can lose up to 2 RON.

Not sure how long it has to saty and under what conditions but worth bearing in mind if you are going to get serious about this stuff.

I like the sound of Toluene, but how critical is it in getting the mixture right?

John


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## Smootster73 (Oct 23, 2001)

*offer to the board*

if any of you fellows wants some Octance booster then I can get a box of 10 bottles for a good price. Works out around 3 pounds a bottle. 
Just don't ask me to deliver it. It is the millers stuff BTW
See you when I see you.
Send me a pm as opposed to replying to board post.
Nick


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## Jez (Oct 8, 2001)

Glen,

I think you have the answer !

If I drive really slow everyone will see my wheels and I won't need Octane Booster  

Thanks for all your help guys, I'll probably get some booster of some sort just to be on the safe side, I think Toluene is carcinogenic though so I may avoid that one.

Jez


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## Smootster73 (Oct 23, 2001)

*I think that is what it is all about..safety..*

you probably thin the car is flying and if you think so then it will!!
I just want to use it to make sure that I have no issues with det on the rollers when the car and air temp is going up as more cars get in there and warm up the ambient temp.
Better safe than sorry.


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## Mycroft (Apr 13, 2002)

Hmm, that is interesting, the tests we did here was for the Motoring Industry 'watchdog' JDPower and the results were not good, no one (independent) has EVER been able to match the manufacturers claims.

To up the Octane we used to add a Lead Ether (deriv), this was really nasty stuff in pure form as it almost instantly (in contact with the skin) went straight to the frontal lobes of the brain and destroyed 'Higher Function' responses there, it literally sent you 'mad'.

We now use Benzene to provide this property to some extent, it does not have such a marked effect on the body, it just causes Respiratory diseases in the population at large.

ANY product that does what you want (up the Octane rating) is not very 'nice' to handle.

Toluene is benign in comparison with those two other products is similar in handling qualities to Petroleum spirit, but is the finest additive for Turbo'ed motors we have ever encountered.

It has one other property that really 'makes' it for me because of the nature of its flame propagation it is more temperature tolerant than Petrol alone, you can run higher intake temps with a much, very much, slower power fall off curve, and it won't fall before 45C has been reached, a full 20C above petrol.

I would still like pointers to this Millars stuff that had any 'real' info on its constituent parts, all I've found so far is not helpful at all.


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## Smootster73 (Oct 23, 2001)

*jesus...*

you got a chemistry degree dude.
I just bung it and hope for the best!!


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## Fuggles (Jul 3, 2001)

*Which Toluene?*

???

BUTYLATED HYDROXYTOLUENE FOOD 
TOLUENE / SBP BLEND
CRODA TOLUENE/IPS1 BLEND
ETHYL-P-TOLUENE SULPHONATE
PARATOLUENE SULPHONIC ACID
TOLUENE

???


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## Smootster73 (Oct 23, 2001)

*????????????????*

what about if you pee in the tank after a session on the aftershocks? 
It has been known to strip the paint off supras and subarus in the local area that I am not a big fan of!!




JOKE JOKE JOKE JOKE!!!


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## Scott J Davies (Oct 10, 2001)

Nick 

Your Boat has been known to strip the paint of local supras and subarus let alone your wazz

SJD


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## Fuggles (Jul 3, 2001)

Nick,

I like your style.

Ever thought of putting loads of octane booster in and then parking in front of a Scooby/Supra and revving the engine hard before taking your foot off the gas quickly?

:smokin:


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## Scott J Davies (Oct 10, 2001)

Nick 

Your Boat has been known to strip the paint of local supras and subarus let alone your wazz

SJD


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## keith (Jun 29, 2001)

*MILLERS CVL*

COMPETITION VALVE LUBRICANT

FOR SINGLE SEATERS AND RACING SALOONS
SO IT SAYS ON THE BOTTLE

IT CONTAINS

METHYLCYLOPENTADIENYL
MANGANESE TRICARBONYL
XYLENE

GOD KNOWS WHAT ALL THAT DOES BUT WITH THE POWER FC 
HAND CONTROLER WHEN I RUN THE CVL IT DOES NOT SHOW 
AS MUCH DET AS WHEN I RUN THE CAR WITH SUPER IN IT
SO I THINK THIS MUST BE GOOD.

OVER TO YOU MYCROFT


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## Mycroft (Apr 13, 2002)

At first glance that is Redex with a xylene compound to keep the temp high and inhibit smoke, but I'll put it through the system 'cos there must be more to it than that!


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## Scott J Davies (Oct 10, 2001)

Mycroft 

Whilst you are doing that can you put NF through the system as it feels the best I have used and claims to have special ingredients:

http://www.nitrousformula.co.uk/

Ta 

SJD


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## Mycroft (Apr 13, 2002)

OK, the CVL is just a boost of the additives already present in OPTIMAX type fuel, the XYLENE is (as I suspected) just a 'hot' benzene that is meant to 'free' the Magnesium held in a safe compound that is the METHYLCYLOPENTADIENYL bit, (had me fooled for a moment) The MANGANESE TRICARBONYL is the main lubricant and is kept to minimum in 'normal' fuels because of its 'acidic' action. It is useful in getting rid of hot carbon particles left over from combustion, these particles can cause early detonation of the fuel/air mixture. These particles for reasons of ionic attraction like to 'hang around' the valve head this stuff gets them out of the way. Too much of it and the valves will pit badly.

The reason for the magnesium (in 'liberated' form) is to change the flame front and to fool the knock sensor, there will be very little in the way of 'octane boost' except possibly if the suspension fluid is toluene based, which I think it might be as the carrier fluid would need to be of that family of chemicals and it is the most suitable.

Can't find anything useful on the NF, post it if find it.


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## Peter (Jun 27, 2001)

Mycroft,

There's loads on NF here:

http://www.gtr.co.uk/forum/upload/showthread.php?s=&threadid=1238

Look for the posts by Dingy (Steve).

Peter.


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## Mycroft (Apr 13, 2002)

*Update.*

Despite numerous faxes from both me and the Institute 'NF' have not been very forthcoming, they just sent a 'standard' reply that basically said we have our own indpendent testers and they don't need further testing at this time. 

That is not very encouraging, (for many reasons) but they might just have a secret and guarding it jealously.


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## Mycroft (Apr 13, 2002)

*slightly off topic, but of interest I think.*

Why is Optimax so variable? 

Age, 'Optimax' has a 'tank life' it degrades quite rapidly as the super hot benzene 'loses' it volitility after just 40days in the tank [the one in your car or the one in the ground at you petrol station. 

From this day, if you use it, then ask the attendent when the last delivery of it was, if he can't answer then get the Manager, I've started doing this lately and they are blissfully unaware of the time thing so answer with a flourish of paperwork and a quizzical look. My rule is simple, look at the docket, it says size of tank 10k ltrs, the discharged amount AT LEAST 90% is needed to keep it at the 97/98 ron, the stuff in the tanker will be 98. this started from the simple question posed me 'What RON is Optimax' the answer is......enhanced 95ron...this is to avoid prosecution by the Customs and Excise if they perform one of their checks. 

It also scrubs the tank, and this may well be what fooked Adis' cats, his explanation of events fits the dirty tank scenario, apparently the smallest tank on the forecourt is selected [this bit also explains why it is not available nationally] It is cleaned and sealed with an inert gas awaiting its new load, the inert gas does escape and if the gas is not present the new surface scales into rust, the oxide is bad for the SH Benzene and makes it behave oddly during burning, there is a precipitate (solid) formed and this is what I think got Adis cat in trouble, the heating of the solid means that it can perforate the matrix of the cat blowing a hole clean thu it in a few hudred miles. 

Adis problem too has vexed me but now I see a good reason for the odd occurence. 

Any input? Anyone? 

> Adi is a member of the LSOC who has had a something odd occur to his 1JZ engine and cat. (from the LSOC)<

If this is too off topic, but of interest, then I'll take it out and put it in a separate heading.


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## Hugh Keir (Jul 25, 2001)

*DETONATION AND PRE-IGNITION*

Just to stir it up a bit,

There are two effects that fall under the category of knock.

One is Pre-ignition generally caused by carbon deposits, exposed and glowing spark plug threads, thin edges on your head / pistons glowing etc. This causes the fuel to ignite before the ignition spark.

The other is Detonation caused by Lean fuel mixture, Fuel octane too low, Improper ignition timing and too high boost this causes secondary spontaneous combustion in addition to the spark induced flame.

In both detonation and pre-ignition, it is the collision of the flame fronts that causes the classic pinking sound.

Not much difference between the two, but you can deal with pre-ignition by re-building your engine to a higher specification, whereas detonation requires an adjustment to the management of one of the following - Boost, ignition timing, Octane rating or combustion chamber temperature.

You could of course use water injection to control the combustion temperatures - might even be cheaper in the long run when compared to a lifetime of octane enhancer.

You might also consider that the higher the octane the slower the burn of the flame front and more often than not less energy available from the higher octane fuel. 

You can of course run more boost and create more power that way, but it would produce more power if you could run the same boost as the high octane example with low octane fuel + water injection. Just depends if you want the absolute maximum power at any cost which is then high octane fuel + high boost + water injection.

That is unless you use some oxygenated fuel like nitrous which allows the argument to go on and on.

All of the above assume you can tune your engine to take advantage of the different fuels - no trivial task.


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## Hugh Keir (Jul 25, 2001)

Mycroft,

Read with interest some of your earlier comments, especially 

"What we did find was that the 'better' ones changed the properties of the 'knock' and this fooled the engines sensors into thinking all was OK. "

Given that knock sensors are high frequency microphones listening for the sound of the flame fronts colliding, how do you fool them into thinking things are OK, surely there is either the collision noise present or not.

Knock sensors can sometimes be confused by harsh engine noise / harmonics into thinking that knock is present, but I am unable to grasp how it can work the other way round.

Were the tests on octane boosters carried out for JDPower published and can you copy extracts?

I believe there are two types of knock engine that can be used to judge fuel octane, one runs at 600 RPM and one at 900, can you tell us more about the tests and why there are two types of engine.


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## Hugh Keir (Jul 25, 2001)

*Make your own Octane Booster*

I take no responsibility for any use you may put this formula to, but here is a DIY octane boost formula that was offered by an American DIY tuner.

How to make your own octane booster (this is the basic formula of one of the popular octane booster products). 
To make eight 16 ounce bottles (128 oz = 1 gal): 

100 oz of toluene for octane boost 
25 oz of mineral spirits (cleaning agent) 
3 oz of transmission fluid (lubricating agent) 

This product is advertised as "octane booster with cleaning agent *and* lubricating agent!". Diesel fuel or kerosene can be substituted for mineral spirits and light turbine oil can be substituted for transmission fluid.

Mycroft, where are you lets have some more of your gems.


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## John Lowe (Feb 20, 2002)

Try a half-bottle of 16 year old Single malt......it smells nicer than Silkolene and tastes better too. 

Don't put it in your tank though!

Hic!


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## Mycroft (Apr 13, 2002)

*Holiday!*

2 weeks in France......dreadful.

Hugh, most of your 'knock' stuff is correct but some of it is 'put that way' to make it digestable to 'Mr Average', you are all here a 'cut above' that so you deserve a better and exact answer as to how exactly a knock sensor actually works (providing it is OK to post it here) and will do so tomorrow. It will take me a little while to find all the 'stuff' but will put it here. (with the same proviso)

The tests were not for general release.

I saw that 'formula' too, don't like it. Toluene with splash of Iso propyl alc. now that will do nicely!


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## alex h (Mar 11, 2002)

*Re: Holiday!*



Mycroft said:


> *
> 
> I saw that 'formula' too, don't like it. Toluene with splash of Iso propyl alc. now that will do nicely! *


Why? I'm not a chemist so I don't know what Iso Propyl Alchohol will do/add to the mixture. Can you expand on this please?

TIA


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## Mycroft (Apr 13, 2002)

Because that formula will destroy the Steel used in Japanese valve seats ......bye-bye engine!

Never do anything unless you check carefully with 'Juan Hunose' toluene as a pure additive is very good alone, you need to take great care and 'work' on the ratio of Toluene and Gasoline.

Just found an old paper of mine regarding toluene and other additives, I had forgotten this particular research paper due to at that time a change in course in the research, the work and therfore the paper were not completed but the following piece might interest some of you.

'It follows that simply adding 1% (± 0.2%) by vol. to the Toluene with something as rudimentary as AP75 or WD-40 will give added cooling to valveheads without the usuall precipitate forming, the exact quantity seems to be a co-relation of specific output per litre.'

Exactly how you get the stuff out of the cans is you problem!


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## Mycroft (Apr 13, 2002)

Well my patience in getting anything from NF run out yesterday.
So I bought some.

It appears from the initial break down to have rather a high Iso-parrafin content, which is interesting from a lot of angles and would explain why you would not put too much in.

But on the burn tests I can say it is safe to use as there are no discernible precipitates and the Iso-paraffin will take away the knock from the red bandfrequecies.

This is just the preliminary work and I will get some more lab time at the end of next week, so a few more things will hopefully reveal themselves at that time.

Thanks for your patience.

(If anyone is actually still interested


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## jrpidgeon (Aug 26, 2001)

*I am.*

I read all your posts with interest Mycroft, so keep up the good work. Look forward to your update.

Jason.


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## Hugh Keir (Jul 25, 2001)

Interested - I'm on the edge of my seat waiting for the next instalment.

We still have some stuff to discuss with regard to fooling the Knock sensor though.

Tell us what is interesting about Iso-paraffin?, doesn’t sound like it would be the next drink to order down the pub.


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## Bean (Oct 12, 2001)

Mycroft

Yes please keep those well-informed posts coming.


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## Mycroft (Apr 13, 2002)

Well thats cool.

You're more enthusiastic than some of the students I used to teach!

Iso-parrafins, there are dozens of them and in some parts of the Chemical Industry they are just given 'N' numbers, the ones in the can appear to be in the n31--n37 range, which one really is going too deep into this, I'd be hard pushed to give you good reasons for producing substances so closely related as these.

Essentiallly they are 'bound' long chain molecules, imagine a string of 30 beads, now, the string is interlaced very uniformly and here is the bit that needs the 'leap' of intellectual understanding, these chains (bundles) are dispersed throughout the combustion chamber the flame front when it touches some of these chains causes them to unwind now as they unwind and the oxygen (which, remember, is an acid) rushes in to promote there action (because that is all a flame front is, oxygen particles and some others accelerating to light speed and a few emiiting photons in the process in an attempt to promote the reaction) now as the flame eats through the n-3? the chain unwinds right on the leading edge and this actually slows the flame slightly, but here is the trick in so doing the flame front is slowed but the 'work' done is not decreased the reaction is slower but equally as powerful. 
The way to see this is if you can imagine a long pile carpet, the piles are 4" long and are laying flat, now hang this like a curtain the piles are attached to a gossamer thin lattice the wind blows (flame front) and the piles which are also gossmer thin stand out like fingers but due to a little suspension of our 'big world' physics there is no diminuation of the pressure of the air passing through it is just slowed slightly and expanded in volume.

Now that you are all firm in the belief I've left the planet on a train bound for the 'Mad Star' and I'll get back to work.

One of my colleagues has just read the above and his opinion was priceless 'If there are any people still reading this at the end that wouldn't sign you up for the loony-bin then you've had a lucky escape, it is right in principle, but any half decent Chemist there will go out and top himself after reading that'

Gulp.


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## slippyr4 (May 2, 2002)

*mycroft*

have you got a RO test engine then?


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## kowalski (Jan 12, 2002)

*Mycroft*

Would i be correct in saying that all of the little bottles of octane boosters (NF, Millers etc) are all just Knock sensor foolers???
and none actually boost the octane of the fuel a worthwhile amount?


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## Mycroft (Apr 13, 2002)

Too early to be certain, so I'll hold back on the comment.

But I'm haven't found any effective boost in any Octane value so far.

But this sort of work can give you a side swipe every so often.


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## kowalski (Jan 12, 2002)

*mycroft*

I am sure i speak for everyone when i say i dont have a clue what you are on about most of the time but i do trust what you say, so keep up the good work and keep us all informed:smokin:


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## Mycroft (Apr 13, 2002)

I must admit to being less than 'adequate' on the explaining front.

In a lecture hall, you have 'props' and you can say so much more and put in 'asides'. This medium has definitely highlighted my shortcomings, I can only hope to improve with time.


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## nitro (Jun 27, 2002)

Mycroft
So the fuel companys that are using the same octane booster are full off crap then !!!!!
Is that what your saying ??????


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## dingy (Feb 7, 2002)

OK,

NF gives more Ignition advance than any other, more than using 103 ELF race fuel. FACT.

Most OB claim points, there are 10 points to a RON.

No single bottle of millers will give any UK fuel 101 RON, same goes for pro-boost.

Pro boost is 1-2 RON on NUL
Millers is 2 RON on NUL

Therefore its impossible to have more than a 2 RON increase on SUL or optimax.


Email me if you need any details.

[email protected]


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## Simon (Feb 13, 2002)

*It all sounds very good but....*

Can you get it in single shot bottles yet?


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## dingy (Feb 7, 2002)

Single Shots available next week.


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## Mycroft (Apr 13, 2002)

I certainly do not wish this to generate to a yes/no claim and counter claim, but our testing finished at 10AM yesterday, and after a bit of analysis no one here can find any more than a 0.6 increase in the Octane rating, it is quite cut and dried to all who checked, the only effect is to change the 'frequency' of the flame front and this fools the knock sensor and the ignition is noy retarded.

I will happily accept that this just the opinion of a few people and I certainly cannot state the stuff is a waste of money as that is inflammatory and I do not wish to inflame anyone.

In the end it is a matter of choice, I will continue to buy Toluene and use it judiciously in my car, I have done with no ill-effect for nigh on 3 years.

there is a thread above which asks about Aviation fuel, my advice there is simple and very succinct...do not touch it, your valves will die very soon after use and the cold start and vapour propogation could lead to a fantastic fire in the plenum, the car literally burns itself out, I have first hand experience of this (James a good friend from the past destroyed his Cosworth in waht was simply the most spectacular manner imagineable.

It burns too hot for road cars.


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## Bigsly (May 30, 2002)

*Info??*

Mycroft,

Thank you for your very valuable input i find your info very interesting also working at a chemical company myself.. 

Could i be a pain and ask what % would "optimum" to add to optimax on a regular basis for a good return...

Thanks & Best Regards

Stu


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## Mycroft (Apr 13, 2002)

I found that Toluene with about 2% iso-propyl to be best at around 7% by volume of the fuel used.

So, simply mix 5ltrs toluene with 100cc of Iso-propyl, mix this with 65ltrs of Optimax or 60ltrs of SUL did just the trick for me.

I pulled a 12.2 quarter using that mix, it make the car very brutal at the top end as it is here that the toluene really punches its full weight.


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## Peter (Jun 27, 2001)

So are you saying that by simply adding of the toluene mix to your normal fuel this produces a substantial increase in power without making any adjustments to your ignition timing? 

I would have thought that to take full advantage of a higher octane fuel you would need to advance ignition timing....? A 12.2 in a Soarer sounds very impressive, do you know what sort of time you would do without the toluene mix?


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## Mycroft (Apr 13, 2002)

Without Toluene I can just break under the 13's (12.984).

My timing is set a little ahead anyway and I do mean a little!

If you advance the car too much then she gets all 'frumpy' in the low revs and is not smooth enough for everyday use.

Using Toluenen you will find that for the first few thousand miles you will need to change the oil twice each time at 1000miles, this is because the carbon deposits left by the 'ordinary' fuel are being 'dissolved', it is not impending doom!

Your car always runs smoother after using Toluene for a while and even if you return to 'ordinary' fuel the car is quicker than before.

I use Platinum plugs, that are normally set at 1.1mm I always regap these to 0.9mm.


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## JasonO (Jun 29, 2001)

So where can I buy Toluene ?


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## MattPayne (Apr 11, 2002)

Mycroft, you need to start making barrels of this toulene, iso-propyl mix  you would make a killing ere... I can already see the queues forming...


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## Mycroft (Apr 13, 2002)

It is tempting, I have a supplier and a licence for it (amongst others) storage is not too big a problem, but I'll let some entrepreneurial type go for it, not really my 'bag' so to speak.


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## Peter (Jun 27, 2001)

*Really confused now....*

Mycroft,

Don't get me wrong here as I am genuinely interested in your experiences with toluene and your car but to get an improvement of nearly 0.8 seconds over a 1/4, the power hike is simply astonishing if you are putting all that improvement just down to toluene. Given the weight of the Soarer, this must equate to well over 50 bhp...!

You also mention that "My timing is set a little ahead anyway and I do mean a little!" Ahead of what may I ask? Are you saying that it's too far advanced for normal petrol and if you are, surely you'll get more than a "frumpy" feeling from your engine, you'll be in for a rebuild bill when you've blown a piston or whatever due to detonation.

As I say, I'm not a disbelieving type but I can't square what you've said with what little I've learned abut tuning since owning my GT-R.

I'm also interested in Dingy's (Steve) opinion of what you've said about octane booster not really being worth a light. I for one continue to use NF on track and it has a noticeable affect on knock detection on the Power FC. However, I'll gladly stop using it if it's a complete waste of cash!


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## slippyr4 (May 2, 2002)

*Mycroft*

Can you describe your test equipment that you've been using for establishing Octane ratings?


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## dingy (Feb 7, 2002)

I will reply when i have read through this a little more.

Later Today.

AS for toluene, you get more advance from NF than 10% toluene mix BTW.

Plus using toluene on the road is illegal, and its really bad for your health.

Toluene is good tho, but you need a massive about of it.

As for OB not working, i think you will find most are very poor.

NF works, better than any other commercial booster on the market, proven fact.

Keeps oil temps down on track, along with exhaust gases. Plus raises the Octane of the fuel in ron not points.


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## Mycroft (Apr 13, 2002)

The knock sensors reatard your ignition to a point where it no longer detects the knock, now when you reset your timing with (say) the EFI fuse trick, if the car fails to knock (due to being fooled) then the timing stays in its original Japanese spec. the same trick can be performed by shorting out the sensors between (on the Soarer) F3 and Earth, this tells the ECU all is well and the fuse trick need never be used again. The fact that the retardation mechanism is fooled does not mean that the stuff is necessarily doing anything other than that.

To anyone out there reading this, if you believe that any of those little bottles of stuff work for you and your car, then please continue to use them.

I do not want ANYONE to stop using anything that they feel is 'right'.


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## dingy (Feb 7, 2002)

So are you basically saying the OB fools the Knock sensor ?


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## Mycroft (Apr 13, 2002)

Yep.


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## dingy (Feb 7, 2002)

Right, so knock is det and you saying OB hides det ?

Thats not possible.

Taken 2 engines apart mapped for 103 octane fuel using NF and SUL/optimax with no det on there at all.

I don't see how the knock of your engine can alter if its not knocking....

The fuel can't fool an electronic device that way.


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## Hugh Keir (Jul 25, 2001)

Mycroft,

Knock sensors are microphones that are capable of detecting noise usually from detonation, but can be triggered by harsh engine noise, piston slap etc. 

Knock sensors have no ability to adjust ignition timing. The standard Skyline ECU reacts to the knock sensor output by cutting the boost back to it's lowest setting for the rest of the run until the ignition is switched off.

The Apexi ECU that is used by many reading here only reports the knock value to the hand controller and to the engine warning light above a preset value and makes no ignition or other adjustments when knock is present.

Once knock starts, it takes a large amount of ignition retard to correct the problem, typically 10°. Knock is most commonly caused by excessive combustion chamber temperatures which knock only makes higher. Many systems having retarded the ignition by a large amount will then slowly allow the ignition to advance back to the standard setting. The trick is not to let knock start in the first place.

The EFI fuse trick you talk about is I believe similar to the system employed by Subaru. The ECU can be reset to maximum ignition advance by disconnecting the power for a while. When knock occurs, the map or overall ignition timing is retarded and that value will now be set for future or until the ECU is again reset, unless of course you short out the knock sensor ala Mycroft's procedure. 

My advice is, get your engine tuned correctly and avoid the risk of blowing it up through melted / holed pistons.

Hate to disagree with you, but Octane booster does not fool the knock sensor, knock is either present or not, fooling does not come in to it.


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## TIM_H (Jul 2, 2002)

1st post - new member here.

What a breath of fresh air- compared to all the other BB's i've been trawling lately.

What a fantastic thread - read every word with interest.

If this is a taste of what this board's got to offer, it'll be my main stopping point from now on!

keep it up.

Tim


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## Mycroft (Apr 13, 2002)

Hugh as far as i'm aware ALL japanese Turbo'd motors have the Knock sensor signal to the ECU it is essential to retard the ignition to avoid this continual predetonation, the Skyline would be unique amongst all the performance Turbo cars in Japan if this was the case, I am fairly certain that you will find if you delve deeper into the ECU programming that the Circuit sys. 12a/**** will be the control wire, the ECU then retards the Ign. slightly to stop the knocking signal, it will do this using a load/fire reading taken from the crank timer.

The normal knock sensor on Japanese cars is actually quite basic, cant work much over 2000 rpm and as you say can even be fooled by internal noises that are nothing to do with pre-ignition, that is why rather than develope an expensive 'digital' device some manufacturers fitted 2, I have 2 on my Soarer, I have shorted them out, there is then no retardation of the spark due to this rather crude set-up, the best thing is to buy the latest generation of Digital Knock Sensors made by Nippon Denso, i have tried to buy the ones used on the latest SC430 but the signal from them is not compatible with my ECU.

pre-detonation is a 'growth' item, it bredds on itself, so the ECU works to retard the system next time the Lamda probe kicks in, and you are running 'normally' at that point the upper curve of advance is retarded, and this continues until the car no longer knocks.

I have just checked my files and all cars running OBD2 MUST have this function, and most Japanese cars with OBD1 had this feature too.

I tis easy to fool knock sensors, that is why the system can so readily be 'zeroed', if they were only rarely faulted then the procedure would be made more difficult.

Tim, you're right, this forum and the Soarer forum are the only ones to really debate things with serious intent. Both are great places to post and get real feed back from people who actually take a real interest in the'r cars, its not a 'Biggest spoiler (dick) wins' site!

Something I have just noticed too, this thread is getting rather a lot of 'hits' and will soon crucify the bandwidth restriction yet not a word of 'cool it' from the 'powers that be'. Respect.


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## Peter (Jun 27, 2001)

Bugger, waiting for a reply for 2 days, go off 'air' for a few hours, I miss the reply and my thunder gets stolen! 

The stock Skyline ecu does retard ignition when it detects det. by around 5 degrees I believe. It also lowers boost by way of the pcm boost solenoid near the fuse box. Both these precautions are reset when the ignition is switched off although the piston in the boost solenoid can become troublesome I'm told and does not always return from whence it came. 

I'm still unsure about what function ob performs, whether it fools the det. sensors or reduces det. by way of raising octane levels, two schools of thought obviously. Precisely what form of testing was used to test octane levels with and without ob added to the fuel?

I still can't get my head around Mycroft's earlier post about the benefits of toluene and the comparatively enormous boost in power it gives, just doesn't add up to me. Why don't race teams use it instead of race fuel? How have you managed to run around for so long with your ignition overly advanced without suffering the consequences of det.?

Anybody got any views/knowledge about how Shell Optimax gains it's proven higher octane rating? There is no doubt that it significantly lowers det. compared with other SUL's. Is it just that, higher octane or does it include a form of ob?

Lastly, would Nissan really bother to put a det. sensor into a Skyline which 'cant work much over 2000 rpm'? Why bother since det. at that level of load it wouldn't be considered a threat to the engine anyway?


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## wsurfa (Feb 5, 2002)

*Aviation fuel in your motor*

One of the guys I used to travel to work with used AVGAS in his track car -quite a lto as he had an arrangement with a bloke from Shell ;-). Did it for several years with no ill effects afaik, however his track car was a 1920/30's racing Bentley so that may have made a difference 

Many racing organsiations stipulate use of 'regular' fuels hence the lower use of highly specialist fuels. Although I doubt F1 regular is the same stuff we get from the optimax pump.

cheers

Iain


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## nitro (Jun 27, 2002)

All i can say is if higher octane fuel fools the knock sensor thats why you use the bloody stuff. Its pretty obvious that it reduces the detonation!!! Exactly the same goes for octane boosters as i certainly dont know what the difference is between high octane fuel and fuel containing octane boosters, same stuff !!! Thats what the fuel companies use seems pretty simple to me unless im a backward auzzie !!!!!!
If one is 98 octane and the other when a booster is added brings it up to 98 octane then can some please tell me the difference between 98 octane fuel and 98 octane fuel because this black duck dosnt know ?????????
They BOTH reduce detonation exactly what its ment to do !!!!
as if they didn't then why bother with high octane fuel and octane booster's in the first place.
If any one wants to start shorting out the ecu by mechanicly fooling it then you will get a guaranted result "look for trouble and you'll get it" the knock sensor is there for "YOUR" protection !!! 
For those of you who think you cant possibly get an increase in octane from a small bottle DONT EVER BET YOUR LEFTY ON IT AS YOU WILL LOSE IT !!!!!! :smokin:


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## Peter (Jun 27, 2001)

I'll resist the g'day mate!

What Mycroft is saying is that OB fools the sensors so that they don't register any det. but det. is still there and doing the damage. 

I suppose an important point which Hugh made is if your car is set up correctly you shouldn't get det. anyway but on track when she's hot as hell and if your maps are setup pretty close to the line anyway, it can creep in which why I only use OB for track work now we've got Optimax.

Cheers.


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## Hugh Keir (Jul 25, 2001)

*Fool*

The most contentious word in this thread is " fool ", as has been said by others above, Mycroft is suggesting that knock is still present but the high octane fuel is somehow masking this from the sensor which is not possible.

At the risk of repeating myself, detonation is spontaneous combustion of the fuel generated by temperatures or pressures in the combustion chamber that are excessive. It is the sound waves from the multiple flame fronts colliding that create the sound we call detonation.

When detonation occurs, all the energy from combustion that should have been released over the downward stroke of the crankshaft occurs near top dead centre, resulting in sharply increased combustion chamber pressure and temperature which softens the piston and the pressure blows a hole through it / traps the top piston ring etc.

Detonation will be stopped instantly by reducing the cylinder pressure which is why the Skyline cuts the boost. 

Peters point about detonation creeping in on track days underlines the fact that his engine is experiencing higher than usual temperatures. 

For Apexi users like Peter, they have the option of adjusting the “ high water temperature / ignition “ and “intake air temperature / ignition “ maps to control things, but it sure is tempting to tip in one of these bottles for safety.


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## Peter (Jun 27, 2001)

Hugh,

You are correct about running hot on track, no problem on the road. I've seen water at 103 and oil at 130+ before easing off. She wouldn't make a 24 hour car for sure. 

I've been thinking about upgrading the radiator, Rod had a nice big Apexi one when I was there.

Peter.


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## slippyr4 (May 2, 2002)

I'm siding with Hugh here...

I'm failing to understand how an OB can stop what is essentially a microphone from picking up a noise that is alledgedly still there. Doesn't make a lot of sense.

The sure way to reduce knock, as hugh says, is to lower compression. You see the example of this in that normally aspirated cars run much higher compression ratio's than forced induction cars... If you ran turbo engines with similar boost to a stock skyline at CRs approaching 9.5:1 or more, you'd get a lot of detonation occuring.

The other (but not so significant) factor that reducing boost pressure has is that intake temperatures are lower.... The charge gas gets hot as it's compressed by the turbo, and the intercooler is never man enough to cool the charge right down to ambient temperature before it enters the combustion chamber. So it follows that lower boost pressure results in lower charge temperature before the piston compresses it.

Mycroft still hasn't answered my questions about exactly how he tests for Octane ratings. It's a hard thing to do, and is inaccurate by design. I'd be interested to hear more about his rig.

JOn


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## Mycroft (Apr 13, 2002)

To get to the nub of this, to call anything I have tested so far as an 'Octane Booster' is stretching the term a bit, sure they will add maybe 0.6 of an Octane and therefore they are grammatically 'Octane Boosters', but as a route to deriving power from increased Octane is concerned, that is a joke.

They do have a way of changing the way the flamefront progresses, by using in one case Iso-paraffins, the only 'gain' that you obtain is that your ignition is not retarded and does not return to default minimum advance.

So car has factory spec power of 280hp, the ignition can moderate its output to suit a 'lower' grade of fuel and the car automatically resets the timing and now you get (say) 270hp, you then reset everything and add 'Octane Booster' the car starts at 281½hp (that 0.6oct 'boost' amounts to that) and the car does not retard the ignition 'cos it can't see the detonation.

You have not gained any real power!

Now when I add my bit of Toluene I get real power, the knock sensors don't retard 'cos there really is no pre-detonation, the higher Octane gives more power, real power, not just what I had 'originally'.

Times wise, they were the best times achieved in each guise, they were not on the same day, they are just 'Best Times With and Without Toluene'


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## Peter (Jun 27, 2001)

Whoa, big swerve....


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## Mycroft (Apr 13, 2002)

*Re: Don't bite me please.*



Mycroft said:


> *This Millars stuff, is it a 'real' octane booster or a 'Knock sensor fooler'
> 
> I ask because here at the Institute we have conducted a lot of tests on 'Octane enhancers' Not one actually does 'what it says on the can' except by only the thinnest of margins. The best result was an improvement of 0.59 of an octane. (about the same as the pump tolerance)
> 
> ...


First post, no swerve!


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## Hugh Keir (Jul 25, 2001)

Hallelujah,

Mycroft tapped away with

“Now when I add my bit of Toluene I get real power, the knock sensors don't retard 'cos there really is no pre-detonation” 

Great I am sure we all agree.

And with 

“ Octane gives more power, real power, not just what I had 'originally'.” 

I am sure we can also agree that your technique has provided more advanced ignition settings and the high octane fuel can be used to your advantage to create more power.


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## Mycroft (Apr 13, 2002)

It has been a long day, can you explain the above Hugh?

I am a little lost!


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## Hugh Keir (Jul 25, 2001)

Mycroft,

The stumbling block for me in this thread has been the comments about fooling the knock sensor.

In you last post, you said "'cos there really is no pre-detonation” and that has been the reality for me all along, not that you have fooled the sensor, but that you actually achieved the desirable result of having no pre-detonation.

My guess is that if you run toluene all the time, you would not need to short out the knock sensors either.


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## Mycroft (Apr 13, 2002)

Forgive me I really am failing to make myself 'plain' here.

Only if you genuinely up the Octane rating will the pre-det. not occur.

All those products we have tested DO NOT increase the Octane rating in any significant way.

The only way to stop the ignition being 'retarded' (which is how most cars running 'ordinary' fuel run most of the time) is to prevent the Knock sensor from detecting the knock, additives do this by changing the 'characteristics' of the knock, my colleague has even proposed that the added lubricant cushions the sound and tries to fool the sensor this way also.

When running 'optimax' I can short out the sensors if I wish, I did the short originally to test whether or not the sensors worked as I had guessed they should.

I may have found a source for a Digital knock sensor, this will not be fooled by the 'Octane Boosters' and I am making enquiries, we will buy a dozen or so and will happily fit one to a Skyline that at present or in the future is or will be running one of these 'boosters'.

Digital detectors will be able to pick-up knock right thru to 8k+.


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## Hugh Keir (Jul 25, 2001)

Mycroft,

So, I take it you disagree with my earlier statement " detonation is spontaneous combustion of the fuel generated by temperatures or pressures in the combustion chamber that are excessive. It is the sound waves from the multiple flame fronts colliding that create the sound we call detonation" ?

Please give us your definition of knock.

I am happy to agree that you have increased the Octane rating of your fuel with toluene.

You also need to be aware that a large percentage of Skylines in the UK are fitted with programmable ECU's and can approach this problem directly by adjusting the maps.


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## Mycroft (Apr 13, 2002)

#It is the sound waves from the multiple flame fronts colliding that create the sound we call detonation#

Wrong I'm afraid.

It is simply a pressure spike at around 6400hz. The sensor is tuned to this frequency and this frequncy only.

Knock Detonation; is the spontaneous combustion of the 'end-gas' in the chamber. It occurs after normal combustion has been initiated by the spark plug. Due to heat and pressure, the end gas in the chamber spontaneously combusts. 

'Pre-detonation'; is defined as the ignition of the mixture prior to the spark plug firing. Anytime something causes the mixture in the chamber to ignite prior to the spark plug event it is more correctly called pre-ignition. 

The two are completely different and abnormal phenomenon only by detecting the former can you hope to prevent the latter as it cannot easily be detected until it has done some damage.

Whilst I'm on this 'definition thing', a word about Octane, it is simply a way to express anti-knock level it relates perfectly to the speed of the flamefront, the higher the rating the further the timing can be advanced and there fore the 'perfect' strike point can be achieved with the flame at its fastest at 14deg ATDC.


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## Peter (Jun 27, 2001)

*Re: Don't bite me please.*



Mycroft said:


> * We found the only viable (and not very at that) alternative was Toluene, mixed at 9 parts pump fuel 1 part Toluene, this gave about 4% increase in power at the flywheel, across the rev range.
> *


How does a 4% increase in power translate into nearly a second off your 1/4 time?

What method did you employ to measure the octane ratings?

Steve,

Have you got any information from NF about the constituent parts of NF and how these boost octane levels and reduce/mask det.? What does the '6 ron' on the NF bottle actually mean?

Peter.


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## Ian SuttoN1 (Aug 14, 2001)

*NF?*

Peter im doing the NF bulk order next week I take it you don't want any?

...Ian


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## Peter (Jun 27, 2001)

Hi Ian,

Have you used up all the last lot or have you become a supplier now?  

I don't know what to think to be honest. I keep getting a whooshing noise which I thought was my dump valves or something, turns out to be some of these posts flying straight over my head!  It would be nice to get a definitive answer but that's probably wishful thinking.

Peter.


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## Ian SuttoN1 (Aug 14, 2001)

True Peter I await the results on what OB is the best and why.

Until then and mainly for a safety point of view I will still add NF (3rd of a bottle 100ml) per tank of shell Optimax. I hear you lose up to 3 ron on SUL if it stands in the tank also if it has been at the petrol station for some time (could be myth) on the basis I use my car only at w/e's it makes sense to me.

Regarding supply, no i'm not a dealer its just that I have a contact and it arrivres sharpish in bulk! £10 a bottle still. 

let me know ..Ian

PS I'm at DONNO Sunday for the SIDC day!!


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## Peter (Jun 27, 2001)

I've still got 4 bottles here so I pass this time thanks.

Have a great time on Sunday, is this the first time on track with the new engine?


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## Ian SuttoN1 (Aug 14, 2001)

No Peter I did Goodwood in May but the pads were to hard and the discs warped like hell, it was like ABS coming on . Viabrations through sterring wheel weren't good braking from 135 to 50 to take the right hander after the back straight!

Sorted now !

...IS


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## nitro (Jun 27, 2002)

I'm sure you could do better than that, Nitro - Admin 


*EDIT - Admin*


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## Mycroft (Apr 13, 2002)

Nitro apologises - Admin 

A very emotional, but in the end useless post, I have stated twice before in this thread that if you are happy buying any OB you presently use then continue to do so.

Peter
I think you will find as already stated here that 6 ron relates to POINTS which is exactly as I have found!

What difference have you found in your best times at quarter days? Do they not vary at all!!, mine do and so does everyone elses, 0.8 of a second difference is quite common when runs are on the same day, let alone a few days apart!

*EDIT - Admin*


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## Hugh Keir (Jul 25, 2001)

Agree with most things in your last but one post, but It is simply a pressure spike at around 6400hz. The sensor is tuned to this frequency and this frequency only.  seems inconsistent with other stuff I have read

I have a spec sheet from Bosch which describes the function, installation and use of their range of 3 knock sensors. It says that they monitor frequencies in the range 1 to 20 kHz and talks about the sensors linearity between 5 and 15 kHz which is fairly steady.

Looking at the signal evaluation module that Bosch sell to interface with the above sensor, it is capable of analysing for 9 test frequencies between 5 and 16 kHz which presumably allows the individual car manufacturer to focus in on the frequency of most interest.

I have also read somewhere that the frequency produced by detonation is loosely connected to the bore of the engine.


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## Mycroft (Apr 13, 2002)

There is no inconsistency between what I posted and the Bosch info, the sensor needs to be a good quality listening device and the linearity does the unit credit, but being able to hear all the different frequencies is essential so as to provide a 'white noise' against which the 'ping' is heard. Think of it this way, if it only sends a signal back to the ECU when it hears anything, at 6400hz then it would pickup the occasional harmonic from the valves etc, it would be difficult to distiguish if this 'other' noise was really a 'ping' so the unit sends a continuous signal from all over the frequency range the ECU is programmed to use this, then when the 'ping' arrives it can distinguish it for what it is.

the ECU requires a comparator.


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## Peter (Jun 27, 2001)

Mycroft said:


> *What difference have you found in your best times at quarter days? Do they not vary at all!!, mine do and so does everyone elses, 0.8 of a second difference is quite common when runs are on the same day, let alone a few days apart! *


Mycroft,

Have to admit that I've never done a 1/4 time, much prefer using the car for what it was designed for, circuit driving. So, and I'm not trying to trip you up here, despite you posting 

"I pulled a 12.2 quarter using that mix, it make the car very brutal at the top end as it is here that the toluene really punches its full weight."

and

"Without Toluene I can just break under the 13's (12.984). " 

you are not actually putting this down to the additional power toluene can give, more just inconsistency in your driving, my mistake.

Why do you refuse to answer how you tested octane levels? It's been asked of you some 3 or 4 times now.


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## Mycroft (Apr 13, 2002)

Only with Toluene, can my car catch a 12.2!

I thought I had answered this but re-reading the thread I realise that I haven't.

The devices we used were Bumah Octet (old and slow but a very good final check and we have an array of simple di-electrics the latest one and the most accurate is the Kavlico it is now issued to the HM C+E to replace the vans they used to use, they do the test with the hand-held, the results are to 2 decimal places. which is about one eighth of a RON point. They have a website, we bought ours from there.

We used to use the Petroleum Research handheld but that was fiddly and not too accurate and could be 'fooled' by Iso-parafins! so there may be a clue in there!

The latest devices cost under a £1000 and work fantastically well and are used now by the FIA at all F1 events.


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## phatty (May 18, 2002)

Sorry to go of track, but I'd just like to ask Nitro a question.

Does 5:06PM UK time = Pub kicking out time in Oz by any chance?


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## nitro (Jun 27, 2002)

2hundyman Well it depends on what day of the week.
on the weekends yep pretty close during the week around 3.00pm your time


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## Syed Shah (Feb 20, 2002)

Mycroft, (no doubt you will remember me from the Supra BBS):

Now, there is one thing I do not get: That is, why would these companies that produce octane boosters bother changing "flame fronts" and "fooling" knock sensors? Surely doing this would require a lot of work and research, as it in itself sounds very complex, why would they not just produce something that boost the actual octane (much simpler to do)?


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## Peter (Jun 27, 2001)

Mycroft,

One other point too, you mentioned that the stock knock sensors fitted to the GT-R (amongst others) were next to useless. Would it surprise you to know that well established and respected tuners in this country rely upon the stock knock sensor to determine whether the car is detting or how near the car is to detting whilst mapping the car? 

I would certainly be interested in fitting one the digital knock sensors you had found if that were possible. It would be very interesting to compare this with the stock sensor.

Peter.


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## nitro (Jun 27, 2002)

SYED SHAH
You are not welcome on this site!!! you are by far to intellegent and say things so simple. Mind you there are a few others on here as well that know whats happining.!!!

This form of communication is not understood in this forum - please employ a dialect more in tune with the rest of the members - Admin 

Thats EXACTLY WHAT WE WANT TO DO IS TO SHOW ON THAT THING THAT WE HAVN'T INCREASED THE OCTANE.!!!!! CLEVER??

If you do a PROPER test and the WORLD std test and it would have to be pretty dam obvious, well at least i thought it would be, but after reading the crap your putting on here you DONT!!!!!!!
The only octane test that counts or is the proven way is the ASTM D2699 test and if you dont know what that is then its the test carried out by the only engine which can do it.
A KNOCK ENGINE !!!!!! and ive even included a pic of it for your small eyes to see.
YOU see it has a moveable crank shaft.!!!!!!! pretty clever hey ????
I was going to send a pic but the file is too big 

*EDIT - Admin*


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## slippyr4 (May 2, 2002)

Nitro

I can kind of see your point, but I don't think anyone on this board appreciates your childish approach, vulgar langauge and unneccessary personal attacks against MyCroft.

If you want to behave like that, please do it somewhere else.

I'm sure others here will agree with me.

Jon


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## nom (Jul 8, 2002)

Hi - I'm new here, but I've been following this thread for some time.
The Mycroft arguments make sense, and the anti-Mycroft arguments are, well, abuse, or lack of understanding - quite reasonable (the lack of understanding) given the level of chemistry involved. This isn't school chemistry stuff and no-one short of a specialist should be expected to understand it - but try, it's interesting when you know!
And also remember that the 'experts' - independant testers and companies - can be wrong, especially as they frequently have their hands in someone's pockets... weigh it all up before deciding, don't just slam someone's (well educated) point of view.
Think, guys - this bloke might save your engine, or give it a few more years life. I think it's worth a bit of encouragement?
Well, I've put myself down for abuse as well now, I think


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## slippyr4 (May 2, 2002)

I don't like Nitro's attitude. It's not called for.

I'm not a petrochemist, but I did learn a reasonable amount about octane/octane boosting/octane testing when i was tuning mini's

The _de facto_ standard method of testing octane is in a calibrated research test engine. Full Stop. 

However, some funny little hand held device could also be accurate... I don't know.

The thing that does not make sense to me is this:- Knock = pre ignition, which means the charge self-detonates before the spark. Knock sensors are simply microphones. They can "hear" the occurance of every fire of the cylinders, and if that fire happens before the spark, then the ECU knows that knock is occuring.

Following on from that, the theory that Octane Boosters "fool" knock sensors just doesn't add up. Does it make them go deaf or something? At the end of the day, if knock is happening, it makes a noise, and a knock sensor will pick it up.

Jon


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## slippyr4 (May 2, 2002)

Nom said:



> This isn't school chemistry stuff



Not true... none of the chemistry here is even slightly beyond A-Level Chemistry. That's not to say that petrochemistry is simple; just everything that's been said here has been simplified.


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## Peter (Jun 27, 2001)

nom said:


> *The Mycroft arguments make sense, and the anti-Mycroft arguments are, well, abuse, or lack of understanding - quite reasonable (the lack of understanding) given the level of chemistry involved*


Nom,

There is only one 'anti-Mycroft' argument here, the rest is just debate. I'd wouldn't like to think that my comments were taken as 'anti-Mycroft'.

Jon,

Yes, I agree with your sentiments totally.

Peter.


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## nom (Jul 8, 2002)

Hurrah, we're back on intelligent debate 
OK, yes, the 'school' thing was really 'normal school' as opposed to A-levels  - I certainly covered this stuff (or the theory behind it anyway) at A or S level or whatnot. And Peter, I didn't actually mean you, there's a few others who are a little less thoughtful...

Anyhoo, I think the 'fooling' the sensor thing seems quite possible - the noise may still be there, but disguised. So, 'fluff fluff fluff fluff' sounds fine to the sensor, 'pumph pumph pumph pumph' means there's knock, but what the hell does 'boof boof boof boof' mean? Well, I'll ignore it then, says the sensor. (Please inset whatever noises you think the engine makes rather than mine). But, once the 'boof'ing gets loud enough (i.e. end of effective addition of 'octane booster') then the sensor wakes up to it & hey-presto, the knock is back.
Assuming for a moment that the idea that boosters don't actually boost but instead 'cover up', does this 'cover up' actually help anyway? Or at least partly...
Sorry for the being simple. It is after 4pm on a Monday Mr Brain is still somewhere on Sunday morning... Maybe someone more awake would like to slash my idea (intelligently) to pieces?


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## Mycroft (Apr 13, 2002)

Syed Shah, no I can't say I do recall you from there, but as all I seemed to get was flamed by so many, if you were one of them then please don't follow Nitros example and start abusing me here! To answer your question, that is what I'm trying to discover, but my thoughts go to this, if I sell a full blown Octane booster that needs to be mixed at about 8%BV then it is going to be bulky, very bulky, if however you sell the old 'magic bullet' then it is small and convenient, now call me a cynic but if you can use something that lubricates and cools the valves and adds a little to the octane and masks (a less contentious term than fools, I agree) the knock, then is this a real power filip or is it a 'get around', I suspect the latter, my belief is that this is indeed what we have here.

Nitro, first yeah a test engine is the way to do some testing, it is however a bit 'old tech'. the question i have been trying to answer and getting for the most part valuable feedback from is whether an Octane Booster is worth its name.

Modern testing equipment is a boon to us, it is quick and cheap and this means I don't have to book and PAY for a test run, a handheld device that is as accurate as a room full of gear from 10years ago means that I can post info on here without costing me my Job or emptying my wallet.

I find it difficult to grasp all that you have posted but you seem to be having a problem getting your head around this.

If you wish to pay for a BS test, then PM me and I can arrange this with the Lab. guys. that would be a great service to the club. 

#Knock = pre ignition# Wrong! For want of a better term Knock is a post-ignition, pre-ignition cannot be detected by the Knock sensor, please re-read previous post by me. The knock you here and the sensors detect happens AFTER the initial spark and is a result of end-gas detonation.

Peter you have been exemplary in your questioning and I like to have any reasoned 'case against' you have done this and it has merely made me double check my findings. That is exactly what I want.

Nom good question, my next 'thing' is are the apparent power gains just the advancing of the ignition, as the knock now at a lower less 'resounding' frequency we don't notice it and if this is the case just how far can we safely go without damaging our cars?

So as to not confuse people I will again state that if you are using any OB then please do not stop on account of anything posted here as yet, this is not a conclusion.


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## Mycroft (Apr 13, 2002)

I have found them at last! one of our test units!

http://www.ridgenet.net/~hideseng/


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## Syed Shah (Feb 20, 2002)

Mycroft said:


> *Syed Shah, no I can't say I do recall you from there, but as all I seemed to get was flamed by so many, if you were one of them then please don't follow Nitros example and start abusing me here!
> 
> *


No, you were not 'flamed' by me, in fact quite the opposite at times. 

Anyway, as regards to your answer, well I look forward to your continuing research especially as to why they bother doing this sort of thing in the first place, also, although I am not an expert on cars, I do know that a knock-sensor is merely a microphone to listen for 'knock', this could not be fooled by changing the frequency of the 'flame front'.


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## Mycroft (Apr 13, 2002)

Thats cool then.

The microphone will indeed pick-up all the frequencies, but the processor only wants to hear 6400hz, if it takes notice of other signals then it is not gonna work, if it took 'all comers' you could in theory retard the ignition by tapping on the cam cover or slamming the door on tickover! 

There is good money in these things, their reasons for making the stuff is to make money.

I have a very jaundiced view of this World so just call me a cynic.


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## jrpidgeon (Aug 26, 2001)

It would be interesting to test your theory Mycroft. If I get time I 'might' connect my Signal Generator to the input DET Sensor signal pin on the ECU and disconnect the DET sensor itself (Microphone). If I where to put the Power FC into Knock monitor mode and set the Signal generator to around ~6400hz I should see a Knock level on the Apexi hand controller screen. Using the signal generator, I would be able to see how wide banded the ECU detection signal is and how sensitive, also were the actual focal frequency is (your saying ~6400hz). 
How does the ECU calculate the knock?, is it done by the amount of amplitude/signal strength (loudness) of the knock, or by a varied tap - IE tap.tap.tap, the more taps (knock) it hears the higher the knock volume?. (Just incase I have to use a pulse genetator also).


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## Mycroft (Apr 13, 2002)

The Toyota unit uses phase locking to detect the 6400, what you propose would (I think) work.

To say the least I would be very interested in the result.

Ihave found this;

http://www.streetrodstuff.com/Articles/September_2000/Engine_Basics_I.php


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## Blow Dog (Sep 4, 2001)

I would be most grateful if some of the foul-mouthed here would respect those that have obivously something valuable to give back to the community.

Very interesting reading BTW.

Cheers,

Cem


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## Peter (Jun 27, 2001)

PeterE said:


> *Mycroft,
> 
> One other point too, you mentioned that the stock knock sensors fitted to the GT-R (amongst others) were next to useless. Would it surprise you to know that well established and respected tuners in this country rely upon the stock knock sensor to determine whether the car is detting or how near the car is to detting whilst mapping the car?
> 
> ...


An unintentional swerve I'm sure what with all the 'action' today but what are your views on this? Are you familiar with the knock sensor used by Nissan on the GT-R or are you assuming it's similar to those fitted by Toyota to the Soarer, etc., i.e. next to useless?


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## Mycroft (Apr 13, 2002)

I think I'm right in saying that the Nippon denso unit in my car is the same product as in your own GTR, the 'design' maybe different but the functionality is the same.

Did you read the link above?


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## somberg (Jun 27, 2001)

Signal from a det sensor looks something like this:

http://www.picotech.com/auto/waveforms/knock_sensor.html

Basically it is a piezo sensor that generates a voltage in relation to the shockwaves generated in the block (in the case of the RB26DETT) following high pressures in a combustion chamber. Pinking in the end causes excessive pressures that in turn generate higher-than-average voltage spikes on a det sensor.
Piezo sensors come in two flavours: tuned and non-tuned. I think the RB26DETT are tuned sensors.

I'd be very interested in any test results, I'll probably be doing it myself also because the Motec ECU I'll be using doesn't have a direct det sensing capability and therefore I need to design addditional hardware/software.

For those interested, I have quite a bit more information and articles which I have dug up on the Web last week. If you're interested in these links, send me an email ([email protected] or [email protected])

Andre.


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## Mycroft (Apr 13, 2002)

What i do find interesting in the Picotech thing was the frequency, which to my eyes looks like 16Khz, now (if my music lessons serve me) the fifth harmonic of 6400hz is 16Khz (2½times) as to why they would use a fainter signal (amplitude/frequency) to detect knock is odd!

I coouldn't find out which sensor they were using or if by upping the sampling rate by 2½ times they 'shifted' the frequency notation on the scope.

We use National Instruments software Osc. and I will see if I can replicate this tomorrow (today!) by upping the SR.

Peter I have had a quick glance back and although not praising the knock sensors in our cars my quote was;
#The normal knock sensor on Japanese cars is actually quite basic, cant work much over 2000 rpm and as you say can even be fooled by internal noises# Next to useless is a bit strong, they do work.


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## somberg (Jun 27, 2001)

Have a look at

http://www-s.ti.com/sc/psheets/spra039/spra039.pdf

Will give you a better idea of what's going on.


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## Peter (Jun 27, 2001)

Mycroft said:


> *I think I'm right in saying that the Nippon denso unit in my car is the same product as in your own GTR, the 'design' maybe different but the functionality is the same.
> 
> Did you read the link above? *


I have now, very interesting indeed!  I may have missed it but I couldn't find any reference to knock sensors, only 'tin cans'. How have you concluded that they are essentially useless and does it surprise you that tuners use this knock output displayed by the Apexi Power FC to monitor det. when tuning? I find it difficult to believe or understand why a companies such as Nissan and Apexi would bother to incorporate this function within the PFC and the car to start with if the knock sensor is unreliable....

Another question came to mind when reading this article. Could an engine which is over-fuelling suffer from increased detonation by way of richer end gases making det. more likely? Prior to having my car mapped properly by Rod Bell recently, occasionally I would experience increased det. (assuming the sensor is correct of course) on track. My method for clearing this would be one or other or both of retarding the whole ignition map by a degree or two or adding extra fuel. This without fail reduced the det. readings. Perhaps the latter solution should not be used?

I regapped my plugs last week and, having read this article, I'm pleased and relieved to note that all the plugs were clean (sandy brown in colour) and totally intact.


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## somberg (Jun 27, 2001)

Peter

Maybe you should read the article I posted a link to in my previous post.
I think "essentially useless" means "can be improved upon because the proverbial 80/20 solution has been chosen". These cars are produced as a mass article; I think that if they achieve 80% of their objectives with 20% of the money they're satisfied. In the article you'll find acknowledgement for this. This also explains why a cheap solution like the one of the GT-R is working up to a certain point and why it is better than nothing. Tuners use this because it is all they have. It would be far better to have an individual cylinder detection + control strategy for the full RPM range because that will increase engine efficiency, but that costs a lot of money. Also note that the early R32 GT-R computer was a concept from the end of the '80-s ! I wouldn't say that the R34 computer is the same, but it's not a quantum leap. It is my opinion that car electronics as they are implemented are not always state-of-the-art to say the least. That has a lot to do with cost and the need (or better the lack thereof) for technological innovation.

Andre.


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## Peter (Jun 27, 2001)

Hi Andre,

It's too late to read another long technical article tonight, my head hurts! I'll summon up the courage later on.

I suppose thinking about the stock knock sensor logically, it was probably considered sufficiently sensitive to use with what is essentially a pretty simple det. prevention system on the stock car. It may not have been designed to operate to the level of sensitivity required by 'modern' tuning systems such as data logging with the FC Pro, etc. As with everything everywhere, the accountants had their say no doubt.  

The over-fuelling/increased det. issue interests me as I was told this could be the case quite a long time ago by Mark and I have to say I found that hard to take on board but perhaps he was right after all....? 

Cheers.

Peter.


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## somberg (Jun 27, 2001)

Hi Peter

Last one for tonight, got to get some sleep 

That's why I dislike accountants occasionaly. Don't think it's just the electronics that is affected... I've heard some weard stories about VAG engines in this perspective. Everything comes with a price tag attached !

As to overfueling/increased det: yes maybe. There's another thing you get from overfueling: bore wash.. 

One thing is for sure though: I will run my car only after I'm able to control and log all the parameters needed to keep everything in one piece  

Andre.

PS there are some very nice knock sensors avalailable that will go under the spark plug 

PS2 for sure we'll get to the absolute bottom of this


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## Adamantium (Jun 24, 2002)

Mycroft,

2 things.

1. is that your name, or are you sherlocks older more intelligent brother called upon when he is stuck?

2. I have read your posts with extreme interest and have to say I believe what you have said. I must stress that as a physicist I am duty bound to hate all chemists but what you have said seems to ring true plus you have backed it up by some sound scientific theory that makes sense to me.

My car had previously been mapped for ignition based on the output from the knock sensor. I have a remappable ecu rather than relying on the standard jecs ecu in the 22B to retard the ignition.

What I would seriously like to know, and I suspect you may have no idea about this, is whether the masking of the detonation (or explosive deflagration as I have been told to call it) would still be detectable using det cans?

I think ultimately det cans are a far better way to map so future mapping will be done this way.

Also can you give details or links to the digital knock sensor you referred to and possibly the pricing also. I have just boyught myself a pectel T6 ecu which has very complex knock correction software, and am hoping it may have the capacity to receive inputs from digital knock sensors. Due to its complexity I am guessing it does.

more importantly can you let me know where you got the information about the 2k rev useful rev limit of the basic japanese knock sensors.

many thanks,

Adam


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## somberg (Jun 27, 2001)

Adam

I've looked at Pectel years ago.
You wouldn't happen to have an electronic manual or a link to it, that you could provide me, would you ?

Andre.


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## somberg (Jun 27, 2001)

Faster than my own shadow  www.pectel.co.uk


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## pat (Jul 9, 2002)

Yikes, long thread 

First a few basics... knock is in general an "abnormal combustion event". This can fall into many categories, such as pre igniton, "detonation" etc. Each has differing characteristics, and will "sound" different listening to the engine through "det cans". In most cases it upsets the cylinder pressure curve, and may or may not have an audible presence. I would assert that the only true way of detecting such events is by actually measuing the cylinder pressure curve using devices such as the optrionic pressure sensors made by Optrand and used by F1 teams. The actual detection system would presumably employ some DSP algortim... first gut reaction would be to use a nonlinear time variant tansfer function with a finite impulse response but I'de really have to sit down and think about it.

There are many knock sensors available with varying characteristics; for example NTK/NGK have low Q, high Q and flat response sensors. Simply using a high Q sensor with a gated detector would not be sufficent to tell the difference between the background noise and the actual knocking signal unless the signal processor had an attack filter, measuring the sudden increase in amplitude at the centrepoint of the response curve (which may or may not be 6.4kHz). Probably the best method of detection while minimising the number of false positives while not missing any events would be to use a linear response sensor with a DSP system that looks for abnormal variations in a spectral analysis of the signal composition. It would be reasonable to assume that there would be an occurance of a spike centred on 6.4kHz with further harmonics, a phenomenon which could reasonably safely be linked to the presence of kock of some sort. That doesn't eliiminate the possiblilty of weird effects related to (for example) valve bounce being coincidental with the knocking signal, but gating the knock detection system to a window centred about the combustion cycle would reduce the possibility of false positives. The trouble with engines with a higher number of cylinders is that you end up with more power strokes per revolution and thus the percentage of the revolution open to the detector by the gate will increase, thereby increasing the likelihood of false positive detection. It is for these, and other reasons, that I belive that cylinder pressure curve monitoring is the only true means of reliably detecting the presence of knock.

With regard to the effect of the octane boosters, much has already been said. There are two (probably more) angles to look at this from. Each phenomenon (pre ignition, "detonation") has differing criteria for the fuel's characteristics. 

If we assume that (and this is not a safe assumption) there are no glowing deposits in the combustion chamber during the compression stroke then pre-igntion will be caused only by the adiabatic compression of the charge causing the temperature to exceed the autoignition temperature of the fuel and thus the mixture lights up before the spark lights the mixture. There are at least four ways to control this phenomenon... a) reduce the initial charge temperature, b) reduce the compression ratio, c) increase the autoignition temperature or d) increase the standard heat of evaporation of the liquid phase consitutents of the charge. Option a) can be achieved by means such as a more efficient intercooler, driving in colder weather, running less boost etc. Option b) can be achieved by either a piston swap or reducing the effective compression ratio by lowering the supercharging pressure. Option c) is the realm of fuel chemistry (over to you Mycroft!). Option d) can be achieved by mechanisms such as water injection, which effectively increases the relative humidity of the charge and thereby reduces the effective temperature rise due to adiabatic compression. In general though, pre-ignition is much more likely to occur due to glowing deposits, and sometimes simply due to running too much boost for the compression ratio.

The second (note there are more!) and perhaps more common mode of abnormal combustion, often referred to as "detonation" occurs after the spark and generally results from the gas in front of the flame front autoigniting and the resulting flamefronts (and pressure waves) colliding. It's not really a detonation as such, but I won't go into the details of why not as it's not relevant. Anyway, there are many methods to control this type of abnormal combustion event, in general a safe bet is that if ignition advance is reduced then the total combined temperature due to adiabatic compression and the heat from the flamefront is lowered to below the autoignition temperature and the knock is removed. As a general rule of thumb, manufacturers opt for compression ratios which exceed the maximum possible to achieve MBT timing at maximum supercharging pressure; this compromise is necessary to maintain some element of driveability off boost (the effective compression ratio of a low compression ratio in vacuum is so low that the thermal effiiency drops so drastically that the engine make virtually no torque). Knowing that the engine cannot achieve MBT timing on boost the manufacturers opt for the least "painful" compromise... continually running on the limit of detonation and using a knock sensor to react to differing fuel quality and atmospheric conditions.

It all boils down to effective in cylinder thermal management. If one can control (by whatever means available) the temperature rise in such a way to keep it below the autoignition temperature than knock can be inhibited. As stated one mechanism is by reducing the ignition advance. This alters the cylinder pressure curve to move the maximum cylinder pressure away from 14-16 degrees ATDC, which also reduces the maximum pressure at the same time (and also the thermal efficiency). Basically peak temperatures are reduced at the expense of higher thermal input to the exhaust valves. Of course there are other methods available, such as octane boosters (either real ones which increase the autoigniton temperature or "fake" ones which act as flmae inhibitors), reducing the temperature rise by raising the standard heat of evaporation of the liquid phase constituents of the charge etc. 

In the case of actually increasing the autoignition temperature of the fuel, it is possible to maintain the peak cylinder pressure at a point near 14 degrees ATDC (MBT timing) for a higher effective compression ratio or higher initial charge temperature. This is true octane boosting, literally making the fuel "better". Not many things can achieve this (to date, and correct me if I am wrong, the most effective "additive" ever found is still Tetra Ethyl Lead or TEL for short). Any additive capable of functioning in this way will show significant gains in power output. 

Damn, the post is too long, gotta split it!


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## pat (Jul 9, 2002)

Part II....

Sorry about the formatting it all went to pot during the cut and paste from the original post which was rejected for being too long!

In the case of the flame inhibitor, this slows down the flame front, with
less energy released by the burning mixture the charge does not get as hot
with the same ignition advance, and hence autoignition is avoided. It then
allows the ignition to be advanced again and initially it would look like
power has been restored. But there is a catch, of couse. In a perfect
world, fuel would burn instantaneously and thus ignition advance would not
be necessary in order to achieve maximum cylinder pressure at 14 degrees
ATDC. But this is not a perfect world, and ignition advance is necessary
in order to place the peak cylinder pressure at roughly 14 degrees ATDC.
By making the charge burn more slowly, sure the peak cylinder pressure is
reduced at the same advance, and the temperature may be at tolerable
levels at the "nominal" (ie timing before retard due to knock) but because
the mixture is burning more slowly, this timing will still not place the
peak cylinder pressure at 14 degrees ATDC. In fact you'de need to run
even more advance to get it there. The question then has to be asked
whether by slowing down the flamefront and allowing additional advance,
the thermal efficiency at that operating point has been affected in an
advantageous way. Or have you just allowed the engine to run with the
stock ignition map without detonation but not actually making any more
power than it did with the retarded ignition?


The increase in relative humidity (either by driving on a rainy day or
through water injection) may achieve its positive effect on an engine's
propensity to knock either due to the fact that the initial charge
temperature is lower, or due to the fact that peak cylinder pressure is
reduced due to the additional heat "removed" by the evaporation of the
liquid phase water. The water also has an impact on flamefront
propagation, and it could be argued that this has a similar effect to the
flame inhibitor, but it can be shown that the energy "robbed" by the water
can be recovered, and more by allowing greater advance (and hence thermal
efficiency). This is a halfway house between flame inhibitors and "the
real deal", that does appear to give reasonable results (but of course not
as good as real octane boosting).

An interesting point to note about the measurement of Research Octane
Number and Motor Octane Number is that it is performed at 600 and 900 RPM,
respectively, with a variable compression engine (the crank can be moved).
Sadly this is not quite as good an approximation to a real engine as
perhaps one might think, because a real engine has the benefit of squish /
quench areas. These inhibit the autoignition in the endgas either because
they allow heat to be drawn out of the charge or because they squash the
charge down to such a thin "sheet" that combustion as a whole is not
sustainable in those areas. As one varies the compression of an engine by
altering the location of the crank one also adds or removes the effects of
squish / quench. Of course one could stipulate that at no point should the
test engine be allowed to have squish and thus the effects can be ignored,
for test purposes at least. Also important in the real world is charge
stratification and the effects of swirl within the combustion chamber. It
is possible to design a combustion space capable of operating at 23:1
compression without knock if one pays particular attention to charge
preparation, localisation etc. This is well in excess of the theoretical
14:1 limit (or thereabouts) for gasoline SI engines. There's more to knock
control than meets the eye!

I'm sure that there as many many more things to take into account but it's
getting late and at this rate this post is gonna fill up a whole page on
its own 

Cheers,

Pat.


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## kowalski (Jan 12, 2002)

I'll get my coat...........this is so over my head its not funny


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## Hugh Keir (Jul 25, 2001)

*Number of posts*

Pat,

You sure know how to make an entrance, posts 1 and 2 made about the best reading I have seen on this site.

Got any more on cylinder pressure curve monitoring ?

I have seen a spark plug drilled with a pressure sensor and also a piezo electric washer that fits under your spark plug. I contacted the manufacturer of the in plug pressure sensor, but their response was it is work in progress. Autronic also claim they will have system that works with their ECU's in the next year or so, but don't hold your breath.

Some Hyundai engineers also presented a good SAE paper 18 months ago on their cylinder pressure curve monitoring test results which also looked at whether power was still increasing at the onset of detonation.

Thanks for the contribution.


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## nitro (Jun 27, 2002)

"MYCROFT"
Perhaps i have been a bit strong in my point of view and trying to understand the "FOOLING" part, if so an appology is given to you.

"PAT" a great indepth thread


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## pat (Jul 9, 2002)

Hugh,

I did have a datasheet for the Optrand device, I got that a couple of years back, and although it looked very interesting I was put off by the fact that a) they were USD 800 each (and I needed four), b) I needed to drill holes into the cylinder head, c) they required special interfacing as they are optronic devices. At the time they were definitely in use by at least one F1 engine manufacturer, as the datasheet clearly showed (it had the team's name on it, ahem...). The situation has probably improved somehwat over the years and the devices are probably a lot more user and wallet friendly. Optrand still appear to exist, which is a good sign and perhaps it may be worth investigating this again.

As you stated there are manufacturers who make spark plugs with integral pressure sensors. If memory serves correctly, Optrand did do something like that too, and NGK/NTK certainly list such plugs in their catalogue. Interestingly the NTK UEGO oxygen sensor is still "experimental" so it may well be the same for the pressure sensing plug. 

The great thing about these sensors is that effectively you don't need an ignition advance table. Your DSP can perform closed loop advance optimisation by continually keeping the spark at such a point as to get the peak at or around 14 degrees ATDC, and if it detects any abnormal pressure variations it can pull the timing back to a suboptimal position to prevent the onset of detontation.

One thing that perhaps I forgot to say in my previous post, at least not in a roundabout way, and it is perhaps slightly at odds with what Mycroft has said, is that in my view, these octane boosters genuinely DO reduce the fuel's propensity to autoignite *given the same conditions in the same engine*, rather than just disguising the detonation. If it really just disguised it then there would be evidence of det on the piston crowns and you'de end up blowing head gaskets left right and centre. However, the method used to reduce the fuel's propensity to autoignite is NOT to raise the autoignition temperature (which is what a good octane booster would do) but to make the fuel burn more slowly, effectively making the fuel worse than it was to start with, but in doing so saving the engine. You wouldn't necessarily see this effect on a knock engine but you would on a normal engine. It effectively alters the cylinder pressure curve in such a way as to delay the onset of detonation.

In short... an off the shelf "magic bullet" octane booster can save your engine, but it will not necessarily improve the power output. To stave off detonation AND make better power, you need a "real" octane booster such as TEL, Benzene, Toluene etc

It is possible, however, that the effect on the cylinder pressure curve of the "magic bullet" may have a net positive effect on power,, but certainly not to the extent that a genuinely higher octane fuel would have. 

Cheers,

Pat.


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## pat (Jul 9, 2002)

All,

Just a quick note re: Optrand... they now do a "CALplug" whereby they modify a production sparkplug to fit an optronic pressure sensor for continuous high speed use (they suggest motorsport applications). Their catalogue is available as a PDF download from their website at www.optrand.com, and it would appear that they have indeed made the sensors much more user friendly with 0-5V outputs etc 

Cheers,

Pat.


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## Peter (Jun 27, 2001)

pat said:


> *In short... an off the shelf "magic bullet" octane booster can save your engine, but it will not necessarily improve the power output. To stave off detonation AND make better power, you need a "real" octane booster such as TEL, Benzene, Toluene etc
> 
> It is possible, however, that the effect on the cylinder pressure curve of the "magic bullet" may have a net positive effect on power,, but certainly not to the extent that a genuinely higher octane fuel would have. *


Pat,

Very interesting posts although some flew over my head too but good stuff.

So, getting to the point of this thread, on balance, would you recommend the use of a 'magic bullet' octane booster generally? In my case I do only use one for track days when higher than normal water/oil temperatures are seen and, despite it perhaps not being altogether accurate, the det. sensor does indicate an increase in det. readings if I did not use one. I am not looking for or expecting any power benefit from it's use, it is purely as a measure to reduce the likelihood of det.

Hugh,

A few posts back you posted this:

For Apexi users like Peter, they have the option of adjusting the “ high water temperature / ignition “ and “intake air temperature / ignition “ maps to control things, but it sure is tempting to tip in one of these bottles for safety. 

I've had a look through the functions available to me through the Commander and cannot find these. Are they only available using the FC Pro? The water temp screen does not allow me to change water temperatures.

Peter.


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## Durzel (Dec 5, 2001)

I have this screen on mine, and I can change temperatures.

My ECU/warranty card has "FC Pro" on it as a silver sticker. However, I haven't seen any launch control functionality on it - unless Im missing something obvious.


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## somberg (Jun 27, 2001)

Good info Pat, thanks.

a link to a sensor that bolts under a spark plug:

http://www.pcb.com/products/custom/cus140m05.html


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## Hugh Keir (Jul 25, 2001)

Pat,

Thanks again for the extra information, Optrand was the manufacturer of the in plug sensor, but as of my last conversations with them about a year ago, a controller was not availble from them to integrate with the sensor to control the ignition timing.

Your comment To stave off detonation AND make better power, you need a "real" octane booster such as TEL, Benzene, Toluene etc  

Needs to be expanded to say that the energy in these additives is no greater than 98 RON fuel. Only by altering engine parameters like ignition timing and higher boost in conjunction with the higher octane fuel can you release more power.

To find a fuel that by itself increases power, you have to look at the race fuels as provided by ELF which most would consider prohibitively expensive.

Peter,

Am working away from home right now and am not sure which maps are available from the hand controller.

Somberg,

This is the one I had seen previously and is more real world as the voltage can be read directly. The downside is that you have to recalibrate each time you tighten your plugs, you will get a different pre-load and a different electrical start point for the voltage output. Combine this with the output from the ignition trigger disk and you can do closed loop ignition per cylinder to give maximum cylinder pressure at 16° to 18° after TDC. However it's not as far as I am aware been done yet by any of the Motec's or Pectel's, it's still in the evaluation stage by the big car manufacturers.

There is also Ion sensing, which I believe is standard on SAAB cars and is able to detect knock by looking at the resistance across the plug gap. Here is a link to http://www.meaa-mea.com/products/p_ionic.asp a system that Mitsubishi are working on to do the same thing. I think it might be ion sensing that Autronic are working on.


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## pat (Jul 9, 2002)

Peter,

I would certainly suggest that, in the absence of being able to alter the ignition timing curves in an engine management system designed to run on a higher quality fuel, such as Japanese import vehicles, the addition of the "magic bullet" octane boosters will allow the engines to continue to run the advance profile they started with at the factory without the same level of danger of engine demise as running without. It is also not unknown for a knock sensor to go faulty and for this to lead the ECU into a "false sense of security"; given the combination of poorer fuel and an ECU which cannot "hear" the engine knocking, it would certainly be more likely to survive such an episode with the booster in than without.

If, on the other hand, it is possible to alter the ignition advance curves in the ECU, then it may be better to use that approach. It's a difficult call to make because by altering the timing you'll put more heat into the exhaust valves, but you won't be spending an extre 3 to 5 pounds per tank for the booster. Conversely, if you did add the booster and the ECU were able to continue to run the factory advance, it is possible, but not not necessarily certain, that the exhaust valves would not get such a roasting (but, due to the slower burn rate, the effect may be to raise the gas temperature just before the blowdown phase and thus have similar, if not worse effects, than retarded timing... I'de need to measure EGTs in both cases to be sure... it may be quite cool in comparison but without measuring it I wouldn't like to say...)

Hugh,

It is unlikely that Optrand will make a closed loop ignition timing controller per se. I suspect that they will make the sensors and it's then up to the ECU manufacturers to add that functionality to their control code. Fortunately with their more ECU friendly 0-5V output it would be a simple case of sticking a high speed A/D on the ECU and a DSP, or to overspec the microcontroller and use spare cycles in that.

With regard to my comments about increasing power they had the following basis... your factory advance profile ran X degrees, but you had to knock it back to Y degrees because it was beginning to knock. As you have pulled timing away you are further away from MBT and thermal efficiency has fallen. Now by adding the "magic bullet" the timing can be increased again, but you will not necessarily make any more power because of the slower flamefront. Now contrast this to the situation with a "real" octane booster. By not altering (or altering to a lesser degree) the cylinder pressure curve, the peak in this instant is closer to MBT than it would be with the "magic bullet" version. This means that the thermal efficiency is greater at the same ignition advance, and hence the actual power output is greater at the same operating conditions, not because the fuel is able to release more energy (such as a racing fuel), but because the engine is able to more efficiently convert the thermal energy into kinetic energy.

Of course if you are not already at MBT and the octane booster is very good and allows more advance than the stock profile, additional advance will improve the situation further and even more power can be released, as you have stated. And if it's very good indeed then you might get a fuel which is has a higher autoignition temperature, and burns faster than the normal fuel; if the original timing was not at MBT, then this new fuel would make more power again at stock timing because by burning faster it is effectively moving the peak pressure closer to optimum without altering the ignition timing. 

Cheers,

Pat.


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## Mycroft (Apr 13, 2002)

Nitro, accepted.

Pat, nice posts!

Only one thing, the detonation that I believe still happens with OBs' will occur at a lower temp, we can see that with the coolent that is present in all of them, (by coolent I mean a residual light gas that buns cooler, this gas is present in the second det. and has a low flame progation though high ignition temp, similar to diesel) So the second detonation occurs but not so hot it therefore is not as immediately destructive as the high temp 'knock' we all know and hate, it is still destructive but is slower to form the piston head burning characteristic of the 'norm'.

Agree with the rest, 'cos it is correct!

I have got myself some Xylene R3 today and will try that at the weekend, should need about half the Iso-propyl (50cc) so should be fun.

Have you any input on the Digital sensors?
-------------------------------------------------------------
This thread (it seems to me) has become a little unwieldy, would anyone who has posted here object to the idea of pruning it and would anyone want to take on the task?

We have not finished but we are very much closer and i think anyone coming to it for the first time may just 'give up' and although a little'specialised' it has now become essential reading, to clutter it less, please post your answers to this (and we do need consensus) on the thread I will start momentarily.


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## somberg (Jun 27, 2001)

Hugh,

You're right re. the need for recalibration of these under-spark plug sensors. A bit user-unfriendly that is.
The MEAA Ionic Current Detection looks very interesting. The information provided on that web site is quite basic. Is there some more info somewhere re. these or comparable products that you know of ?

Re. Motec: they say it's possible with the M800/M880 to use an analogue input to trim the ignition timing. I'd prefer this to be implemented using CANbus messages since I'd be able to connect a black box with an algorithm inside to control ignition advance with individual cylinder (knock) pressure sensors + others (like crank angle) as inputs using the CANbus to output control data. Since I'm not yet familiar with the Motec hardware, I can't say if it's possible using the CANbus.

To be continued.

Andre.


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## somberg (Jun 27, 2001)

How about this:

J. Auzins, H. Johansson, and J. Nytomt. Ion-gap sense in misfire detection, knock and engine control. SAE Technical Paper Series, 950004, 1995. 

Robert L. Anderson. In-cylinder measurements of combustion characteristics using ionization sensors. 2SAE, 860485, 1986. 

Fei An, Giorgio Rizzoni, and Devesh Upadhyay. Combustion diagnostics in methane-fueled SI engine using the spark plug as an ionization probe. SAE Technical Paper Series, 970033, 1997. 

K.N.C. Bray and N Collings. Ionization sensors for internal combustion engine diagnostics. Endeavour, New Series, 15(1):10-12, 1991.

Some work to do on a rainy Sunday afternoon...:smokin:


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## pat (Jul 9, 2002)

Mycroft,

you may well be right with regard to a lower level knock occuring with the coolent (sp?), but I have found no evidence of this on any piston crowns I have inspected, where engines have been mapped and run with OBs. It may be that although it is still present, its intensity is reduced to such an extent that it is not destructive anymore? Perhaps corresponds to a praticular artifact that sounds like a "fart" through det cans... that certainly is an abnormal combustion even but doesn't sound like someone dropping a pin in a tin can.... but then I may be confusing that with the sound of preignition... too many different types of abnormal combustion modes to remember... LOL

Good luck with the Xylene... at least this one's not carcinogenic... 

With regard to the digital knock sensors, I'de have to do a bit of digging... 

Cheers,

Pat.


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## somberg (Jun 27, 2001)

How about this:

Knock and misfire monitor 

With a sensor the output noise of the engine is measured during each rotation of the crankshaft. With a fast microprocessor the acceleration and deceleration of each piston movement is tracked. The difference of the learned default values and the real-time values are interpreted. 

With two different outputs the engine correction for knock and misfire are given. 

Andre.


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## somberg (Jun 27, 2001)

Hugh

Have you seen this:

http://www.delphi.com/pdf/eandepdfs/Ignition/IonCurrentSens.pdf

Andre.


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## Hugh Keir (Jul 25, 2001)

Andre,

Hadn't seen the Delpi stuff before, but I have seen a controller chip somewhere that has been produced as a stand alone device to provide the management of the per cylinder ignition timing and might with a bit of work integrate with your Motec.

Back home for a day and have dug out the Hyundai paper, SAE 2000-01-0933. Closed-Loop control of Spark advance and Air-Fuel ratio in Si engines Using Cylinder Pressure.

They used Kistler spark plug pressure sensors which were used to measure pressure every degree of crank rotation. 

The main control seemed to be based on the expected performance at 5 points from 40° Before TDC to 40° after TDC. Using this strategy, they were able to monitor the burn process and hold peak cylinder pressure at 16° after TDC for performance and found 38° advance worked for lean burn cruise at 3000 rpm. 

This provided knock, air / fuel ratio and ignition control for optimum performance.

As far as I am aware SAAB have definitely gone further than most on this as I believe all their cars use ion sensing as standard. 
Will try and find out about the control chip.

You can look at www.adrenalineresearch.com/smart.htm and see a system that works and you can buy. Prices start at US $22,475.

There is also a DIY system that has been started. see www.hut.fi/~vvartiov/ion/ion.html

Gota go my missus is bending my lug


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## somberg (Jun 27, 2001)

Hugh

Thanks.
I found that Adrenaline stuff after I posted you; looks quite good; bit expensive though...

I also found an enormous amount of hits on Swedish university web sites; I agree in thinking that they are quite far with this in Sweden (Saab). They're also using the principle on diesel engines.

Looking forward to your data on that chip !

And good luck with the missus.. 

Andre.

EDIT: the 1999 Volvo S70 uses it, BMW also apparently. Wouldn't be surprised to see it in the next gen Nissan as well (like 350Z, R35).


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## nitro (Jun 27, 2002)

MYCROFT what is your email address and ill send you a chart of the independent test and the results including your toulene from a knock engine.
These test were carried out under the ASYM D 2699


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## Mycroft (Apr 13, 2002)

It's in my profile!

So to summarize, the 'Octane Booster' seems to work best by allowing you to advance the timing, but this can be a bit 'hit and miss', if you don't advance your timing then you only get the original settings maintained for longer.

Is that fair?

If so then the next question that screams for attention is whether you should now look to run the fuel with the highest Calorific Value. This is NOT Optimax, the fuel company that produces the fuel wih the highest CV is the Total/Fina/Elf group SUL, strangely this also uses Manganese to replace TEL and Manganese also smoothes the Benzene firing.

the TFE group fuel has a 5.5% higher CV than it's nearest rival, (Optimax), so if you are adding (to some extent) the Aromatics found in Optimax already then surely we must look to use the highest CV fuel for the base!

Whaddya think?


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## Hugh Keir (Jul 25, 2001)

Mycroft,

Spoke to the chemist at Silkolene a year or so back about octane booster. He said that the product that had the greatest effect on octane was iron - better than lead, problem was it screwed up the internals of your engine.

I agree calorific value against octane would be great.

I asked Shell for details of their fuel some time ago and all I got was a generic sheet with no specific details.

Can you give us some more info on the various fuels?


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## nitro (Jun 27, 2002)

MYCROFT NOW YOUR STARTING TO TALK SOME REAL SENSABLE TALK.

Remembering that i was trying to tell you all that this is what the fuel companies are using to add octane to the fuel.
manganese!!!

A lot of optimax has extra toluene added. a friend of mine accidently spillt some on his floor and it lifted the paint offf)
prem 95/96 seems to be a much more STABLE fuel to use which is what i use when i go racing with extra octane boster )

The rule of thumb for octane increase for toluene is every 10% by volume added gives 1 octane increase 

As for the "IRON" theory i dont think so or should i say thats old technology


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## Mycroft (Apr 13, 2002)

MYCROFT NOW YOUR STARTING TO TALK SOME REAL SENSABLE TALK Had to happen eventually:smokin: 

Manganese is essential for Optimax to work (see my paper of Oct. 2000, LSOC) I have found only traces of Toluene in Opt. for the most part it is Xylene and Benzene.

Optimax is high (very high) in Iso-parafins.

Any 'metal' (if its compound is 'soft') will assist the valves and to some extent the detonation. However some metals will cause the valves to rotate to quickly (performance road cars valves rotate at around ½RPM, saloon cars 1RPM) causing valve wear, this what caused all the trouble with Shells last foray into the hi-performance fuels, that had to be withdrawn as the claims against them were getting 'out of hand' I like what Optimax does, but I am always aware that their last effort screwed cars over a 2year period, I hate to feel like a long term test 'guinea-pig'. To some extent I feel that way about all the OBs'.


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## nitro (Jun 27, 2002)

I knew you would get it right )
I would have thought it wasnt exactly the speed of the valves rotating but just the lack of lubricant to protect them.
We are finding here that the 98 is not as stable as the 96 octane fuel it lose's its light ends a lot quicker ??
As for the toluene and other additives added i guess it all depends on the quality of the crude that they start with ?


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## LEIGH (Jul 8, 2002)

OK,

Forget all the crap.

Millers octane boost, will take Optimax to 103 octane.
97 unleaded to 102 octane, and 95 unleaded to 100.2 octane.

Does exactly what it says on the bottle.

I also use Millers Synthetic 10/60W for the engine, and Millers CRX for the gearbox, and CRX LS for the diff.

Leigh.


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## Philip (Jan 17, 2002)

*Millers*

103 octane - don't think so.


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## Mycroft (Apr 13, 2002)

LEIGH said:


> *
> 
> Millers octane boost, will take Optimax to 103 octane.
> 97 unleaded to 102 octane, and 95 unleaded to 100.2 octane.
> ...


'fraid not old mate, 6 octane 'points' means 0.6 of an octane, exactly what it says on the can!!!


Nitro,
Is 'irony' not available in Oz?


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## LEIGH (Jul 8, 2002)

I suggest you look again.
I have the spec from Millers for the Octanne Boost here at my desk.

Picked up from the Autosport show this year at the Millers stand.

Leigh


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## nitro (Jun 27, 2002)

PHILLIP ,MYCROFT YOU ARE CORRECT  
LEIGH
TALKING ABOUT CRAP !! YOU ARE THE KING :smokin: 
I WOULD SUGGEST THAT THE INFORMATION THAT YOUR READING GOES SOMETHING LIKE THIS ;
ADDING THIS BOTTLE TO THE FUEL TANK WILL INCREASE THE OCTANE EFFECT BY UP TO 6 POINTS (SOME USE UNITS / NUMBERS)OR IT MAY READ INCREASE'S THE OCTANE EFFECT BY 5 TO 7 POINTS. 
SO WHAT YOU TELLING ME IS THAT THE "NITROUS fORMULA"
RACE 6 RON WILL LIFT THE 98 UP TO 158 OCTANE GEZZZZZZZZZZ ID LIKE TO SEE THAT !!!!!!!!!
BUT IT WILL LIFT 98 UP TO 101.5 IN 60 LITRES OF FUEL BUT ACTUALLY HAS AN OCTANE EFFECT OF AROUND 103/104 !!!!!!!
OR IF YOUR TALKING COMPARISONS THEN A BOTTLE OF THE "NF" RACE IN 40 LITRES WORKS THE SAME AS "VP 112" OR "AVGAS 114" GIVES THE SAME 1/4 MILE TIMES 11.2 OR 666.4 BHP


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## Mycroft (Apr 13, 2002)

Easy tiger!

Take it down a decibel or 2.


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## nitro (Jun 27, 2002)

:smokin:


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## kowalski (Jan 12, 2002)

*Leigh*

Leigh, isuggest that you go back and read this WHOLE post.


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## LEIGH (Jul 8, 2002)

What ever not worth getting heated over.

Anyone else use Millers oils???


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## Guy (Jun 27, 2001)

*Millers*

I have posted in another thread in general section titled Super-unleaded.....

Conclusion from weekend's driving was:

Super-unleaded = no detonation in my car at either 1.25bar or 1.45bar

Normal unleaded plus Millers = detonation at both settings (less detonation at 1.25bar)

Unscientific conclusion, Millers does not uprate 95 Octane to 97 Octane, or even close.

This is real empirical evidence, I can't comment on the theory as I'm not a chemist.

Guy


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## Tinduck Racing (Jul 18, 2001)

Hi all.....

....How to pass a whole evening:
1) Read this whole thread
2) Read it again 'cos most of it went over my head

 
......blummin' fascinating read folks, respect to Mycroft Holmes..
..Back to the original debate of OBs....for those of us saddled with a paltry IQ of 145 or less.....
a) higher octanes are better
b) and hard to find in small bottles
c) fuel loses octane whilst in storage
...these facts I have gleaned from the thread so far....
So, chemist dudes, what escapes from the fuel to lower it's octane, and can you bottle it and sell it????
  

Apologies for the overly simplistic post,

Jon.


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## Mycroft (Apr 13, 2002)

#what escapes from the fuel to lower it's octane, and can you bottle it and sell it???? #

Aromatics, and they go into that Carbon canister in the egine bay, I would like to design at some point to design a simple 'Davy' type flamegrille and take out the carbon and pipe the 'gas' into the intake, giving a little added power. rather than having it released to the atmosphere after being scrubbed by the Carbon.


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## dingy (Feb 7, 2002)

Leigh, tested MIllers, get this, not even close.

NF one shots now in, 3 RON increase. £3.49

Millers maybe cheaper but doesn't take NUL to 97 yet alone any other petrol.


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## LEIGH (Jul 8, 2002)

Uhmm,

Go back to my last post.

Over discussed.

Leigh


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## dingy (Feb 7, 2002)

Sorry Leigh, you state one thing with no proof, then back down.

Used millers oils in the past, not as good as castrol on track, so i now only use Castrol RS.

Used to use millers until we tested it.



And NF was around


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## Mycroft (Apr 13, 2002)

Leigh, sometimes postings can be interpreted in a way that totally contradicts the real intent.

Your viewpoint is as valid as anyone elses here. 

(I don't even own a Skyline, yet this entire site has been courteous and allowed me to post freely, the truth is that you have more right to voice your opinion here than me!)


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## LEIGH (Jul 8, 2002)

Thanks,

But everyone has a right to post on here.

Dont take it wrong, its just maybe I was miss informed.
I was just passing on information that had been given to me.

On the oil front, I always used Millers CRX 10/60 in my 300ZX (for the last year), until I sold it. It never overheated or used a drop including track days. Millers do several oils, but this is the best one.

I would also recommend everyone changes there Gearbox and diff oil. I did it on my 300ZX, and it run and felt much smoother.

It also highlighted that the diff oil seal was leaking. The level had dropped below the seal, and hence never leaked before.

Once my Skyline comes back I will get the same Millers Oils again for the engine, gearbox and diff.

Leigh


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## Mycroft (Apr 13, 2002)

Cool.


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## nitro (Jun 27, 2002)

LEIGH

As to the misinformed bit, maybe you were and you are not alone here.
In all my dealings with what people read and what they think they are reading or being told i have only come across 10 to 15 people that actally understand this, "POINTS,UNITS NUMBER'S and most of all RON increase's). Here im talking 3/maybe 4000 people. 
Mainly in the parts and accessaries or performance outlets where they sell octane booster's they have NO idea what they are selling or what it does and 9 times out of ten are misreading the label or are reading a misleading label!! 
I hope that many people have read this thread and now know how to read an octane label.

Like yourself LEIGH you quoted as saying Miller's gives 6 points increase taking it up to 103 which you now know it only takes 96 up to 96.6 how ever a greater increase is sometimes achieved and this is covered by the word "EFFECT"

Another point to make is labels often read like this;
Raise's the octane by 5 to 7 points ,units, number's etc;
SO this generally MEANS it will take 92 octane up to 92.7 and takes 96 octane up to 96.5 and as the higher starting octane you use the less increase in octane you get!!!

As for the NITROUS FORMULA !!!!! in 92 octane fuel you will get a 6 ron /octane increase 92 up to 98 and by the way there is no Bull**** here.
BUT in 96 octane fuel it will only give you 4/4.5 octane increase and in in 98 only a 3 /3.5 octane increase. In 100 octane fuel only 2/2.5 octane increase !!!
As i said hope this helps.

My last point is "YES" you can have toooo much octane in your fuel !!! every car is different so every car needs its own octane requirement!! Most std turbo cars get great results with 99 to 100
octane. Thats all you need !!


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## dingy (Feb 7, 2002)

Nitro, UK 95 is the same as your 92



Just so people get it


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## stu_allen (Jul 24, 2002)

Great thread folks, reading it with interest. Keep it up! Oh, and would be intregued if theres any difference with the higher calorific value fuels...


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## tim at svs (Jun 29, 2001)

*some thoughts and some questions*

How refreshing to read such an interesting post/thread especially in comparison to most of what seems to be here these days. Now, to the point of my contribution (?)Seems to me that the octane levels of our UK pump fuels are largely enhanced by benzine ? What by comparison does anyone know about how Japan derive their octane levels ? Apart from anything else, I remember a UK tv programme from a few years back suggesting that the benzine levels present in our unleaded fuels (I seem to remember benzine hadnt been used in leaded) were virtually proven in the States to promote leukaemia (sorry cant spell)meaning that super unleaded users were rather more vulnerable to this. Not that this has much to do with the subject, but it may interest some of us ! America had responded to this problem by installing a bellows/extractor system onto the nozzle of each fuel pump, reducing the inhalation risks. Something we in this country have never done to my knowledge. So, knowing Japan have the best available pump fuel (100 octane ?) how is this achieved, is the basis of my humble inquiry. 
I only ask, because I did spend considerable amounts of time trying to reduce detonation present in a dinosaur-like Nascar Ford road homologation car, albeit around 4 years ago. I tried all varieties of pump fuel, and octane booster. The best booster I came up with at that time was an American product called 104+ (again from memory sorry). That was half decent, but all were frankly relatively inneffective (actually useless is a better word). The only cure I found, after altering the cam (it only had one !), cam timing, distributor advance curve, was finally to buy a 55 gallon drum of VP racing 105 octane 'VP red'. The cure was instant. When I neared the bottom of the can, I sold the car ! This took me nearly two years mind you, and I found no noticeable change in performance after leaving the car static throughout the winter each year. This in itself concerns me somewhat regarding what Mycroft tells us about Opti*ax, because I for one have a habit of leaving my car standing for 2 or 3 weeks at a time, before going for a 'spin'. What if any of our pump Super doesn't degrade with time ? Being as how I would rather go for a spin than a knock !
Oh, and as a final teaser, in those dim and distant days, some engine builders had found that power levels could be maintained with lousy 'pump' fuels by raising rather than reducing compression levels but in turn increasing valve overlap between intake and exhaust events, thus reducing compression pressure not compression ratio. Has anyone tried this with a turbo engine, or RB26 ? Only I like the idea of a responsive off-boost engine that still has plenty of power when on boost. Seems the only route to maintain that is to keep compression levels up, which in turn would appear to be tempting det/pre-ignition. Once again though, thanks Mycroft et al for some interesting reading, always nice to learn.


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## nitro (Jun 27, 2002)

TIM AT SVS
HMMM some good points and questions.
I can specificly answer the one about the 104 plus you were talking about.
YES the 104 plus WAS the best octane booster avaiable up untill 1996/97 it was very very good.
Gold Eagle purchased the NAME, LABEL and the Bottle but not the formula a lady still owns the formula.
It now contains ferosene this may interest the person that was talking about "IRON" as an additive and the first 2 lines of the instructions reads as follows 
Rasies the octane effect by 5 to 7 points!! so go back and read my last post about this.
It has been independantly tested and IT did give this result in prem 96 fuel.
The RED bottle infact reduced the octane level by 0.5 so be carefull!!!
I also have to agree about the cam shaft timing so much to be learnt in this area:smokin: but not much work done ????


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## Tinduck Racing (Jul 18, 2001)

...still the most impressive thread this side of the Hemisphere....

.....watching in anticipation........

Take care Skyliners,

Jon.


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## somberg (Jun 27, 2001)

Once more we have to come to the conclusion that what one really needs, is a reliable measurement tool that detects the quality of the ignition and burning process. And I mean something reliable throughout the whole RPM range. Until that time, you can make mixtures with or without OB's and whatnot but you'll simply not be able to research various options, which is what we are all talking about here.

Andre.


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## SimonEvo Xtreme (Jul 26, 2002)

Hi, Mycroft, finally found my way over from the MLR. Great thread but you posed a question I am not sure was answered. "Should we be using the fuel with the highest CV?"

I have used Optimax religiously in my car but, very occasionally, I have not been able to get it and have used SUL. I notice a difference in the responce of the car (worse), but on one occasion I filled up with Total I didn't. I thought it was just my imagination or that the weather had cooled down. Having read your comments, I now wonder what the reason is. Should I be switching my fuel of choice to Total?

Many thanks


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## Mycroft (Apr 13, 2002)

TOTAL/FINA/ELF produce the highest CV of all the fuels in the UK, that I can confirm today, what you experienced may be the 'sufficient' effect, if you drive your car for a while you get used to a way it performsand you actually ignore the foot work and gain the same momentum for less pedal travel, what you actually encounter is 'efficiency' the higher the CV the better the conversion into motion the less you need to force that pedal down.


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## Ray SA (Jul 26, 2002)

Mycroft ,

Just think of me as a student if I've blown this question , but does calorific value = true ron ? 

Ray


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## Ray SA (Jul 26, 2002)

Mycroft ,

If cv does = ron then why dont we just add benzene . I am aware you are helping me on another thread so if you prefer I will contain my comments there .

Perhaps there is a need for a fuel only BBS !
Thanks
Ray


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## nitro (Jun 27, 2002)

To RAY SA 
Nitrous Formula Octane Boosters are now avaiable in South Africa !!
Try some and see how impressive it is !!


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## Nick Harris (Jul 27, 2002)

Just registered, have read this thread front to back twice, (half a jar of coffee) I work in F1, engines mostly, and this thread is simply astonishing, I can only admire the dedication shown to this 'crusade' for the truth, I have E-mailed Mycroft (last night on another matter) I told him then and I'll say this openly this is the best thread ever, does you all credit, reasoned and reasonable.

A bit effusive maybe, but this sort of thing is so rare.

Nick.


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## InsBro (Jul 29, 2002)

Just read this post with great interest (nearly 2 hours)

A couple of questions

I wonder if SUL is therefore better for power and optimax is better at preventing det?

Where does Wynns octane booster fit in to this?

Thanks

Jeremy


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## Mycroft (Apr 13, 2002)

#I wonder if SUL is therefore better for power and optimax is better at preventing det?#

Sort of, but care needs to be taken finding the right SUL, also to some extent the biggest thing going for Opt seems to be its 'cleaning' function, perhaps the clue is within that, to surmise, perhaps we need to buy a tank of Opt. occasionally to keep the car clean and SUL(High CV) for the remainder.

#Where does Wynns octane booster fit in to this?#

You must decide for yourself, like all these things it is hard to give an answer that is definitive as there are so many different experiences, the real point to my mind is that buying any fuel and adding an OB may not be as beneficial (interpret that as you wish) as you are led to believe and that perhaps we should look for better more real power options.

Nick Harris phoned me today (from Germany) and pointed out something. I'll paraphrase "If any OBs' were that good then the Revenue men would slap a duty on them, they produce only a marginal improvement so as to stay out of the hands of the C&E'

Bloody good point.


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## alex h (Mar 11, 2002)

Which means the goverment think Toluene is great as they try to slap duty on it if you want it for fuel!  But like, who admits its for fuel?? 

By the way if you want some decent fuel you could try here

http://www.76lubricants.co.uk

There is some 106octane unleaded race fuel here...bl00dy expensive though!


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## Hugh Keir (Jul 25, 2001)

*Engine knock detection using spectral analysis techniques.*

Found this spec sheet from Texas instruments showing the application of their TMS320 DSP.

http://www-s.ti.com/sc/psheets/spra039/spra039.pdf

The article agrees with my earlier comments that I believe engine knock is a function of cylinder bore diameter and not at a fixed frequency as Mycroft would have us believe.

Page 7 has the following note " The impulse caused by the shock wave excites a resonance in the cylinder at a characteristic frequency that is dependant primarily on the cylinder bore diameter and combustion chamber temperature "

Page 8 also talks about different tuned frequency sensors can be required for each engine type and the normal range being in the 5 to 7 kHz range.

Andre,

In cylinder pressure sensing

Page 7 also mentions that Toyota is the only manufacturer to install combustion chamber pressure sensors into production engines, might be worth looking into further, especially from the control point of view.


All in all an interesting document.


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## somberg (Jun 27, 2001)

Hugh

I know that paper, haven't been able to read it completely yet. As it happens, we (my company that is) have some nice 320C25 based hardware..

As for in-cylinder pressure measurement: no real need for it since it has been proven, that it can be done with ion sensing. The thermal ionisation current is directly related to the pressure curve. The PPP has to be around 14 degrees ATDC to get maximum efficiency; building a closed loop control mechanism using this is a very interesting option.

Found another company in Sweden (www.mecel.com : subsidiary of Delco Electronics) who might have some nice hardware. Am about to find that out.


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## Mycroft (Apr 13, 2002)

Interesting paper, in appendix C on p47 it shows the actual frequencies used for the software the base frequency is 6140hz which to me ties in nicely with my statement;

#It is simply a pressure spike at around 6400hz#

They must have some trimming available so as to tune them better to the base frequency of the Detonation. so arange of 5-7khz is reasonable and that paper confirms that they do indeed use harmonics to gain further confirmation of the Det. even more pleasing is the use of weighting to these signals giving a fuller picture.

I also stated that there is some variation in th the base frequency due to bore size and material they allow them selves ±400hz, the 5khz is I believe for 2-strokes and really are of no concern to us here.

I noticed that they use very sophicated sampling to obtain 4000 rpm as a max rpm, most cars use a more robust system limiting the the true readings to just over 2000rpm and using the harmonics to extrapolate further retardation again confirming my earlier statements.

Overall a very 'agreeable' paper.


----------



## dan0h (Jul 26, 2002)

Mycroft et al

Very very impressive thread and findings guys!

I actually earn part of my crust modifying a product of Mecel - the SAAB Trionic engine management system which uses the plug gap Ion-flow to detect knock rather than a conventional sensor. Apparantly.

I just know how to make the software deliver more fuel, advance and boost!

What does that tell you guys, I work in SAAB tuning, and am now waiting for my Skyline to arrive from Japan! Front-Wheel-Drive are swear words to me. I say that ... Front-Wheel power is ok, but only when its guided by a HICAS control unit hehe

Anyway, very impressive stuff, I'm trying my hardest to read it all and keep up with the findings!

Dan


----------



## slippyr4 (May 2, 2002)

HICAS is the steering.... ATESSA ETS-PRO is the traction system.


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## dan0h (Jul 26, 2002)

slippyr4 said:


> *HICAS is the steering.... ATESSA ETS-PRO is the traction system. *


Oh arse  I knew that really  wasnt thinking ... very sad considering just how much anorak material I'd read about HICAS and ATESSA ...

*hits himself*

Cheers slippyr4


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## Steve W (Jul 30, 2002)

_Mycroft - GTR BBS_ 



> I found that Toluene with about 2% iso-propyl to be best at around 7% by volume of the fuel used.


What is the alcohol for ? ?

AND, is it OK without the alcohol ? ?

Do you need to 'pre-mix' the Toluene and fill the tank from Jerry's,
OR, is adding it prior to a 'fill-up' good enough ? ?
[ of course the only problem with the 2nd method is carrying
~5Litres of Toluene around with you ! ? ]

Steve W.

ps. Sorry if the above sounds a bit 'DERRR'  , but I've only ever used
'normal' Octane boosters before and they're _easier_ to use
(because of they're 'weaker' nature ?! Want to be a bit more
cautious when dealing with LITRES of solvents !! )

pps. SORRY, I'm a party-crasher from mkIVSupra.net. Please
feel free to tell me to *&%*£$ if you want.....


----------



## Mycroft (Apr 13, 2002)

Welcome Steve,

Toluene is prone to 'flaring' and the alcohol mitigates this.

witout some 'buffer' to ensure smooth burning the straight toly can make a smooth motor a little 'rough', it is just the clouding in the chamber as it ignites.

Mix 5ltrs in a can put it in drive to the nearest station and continue as normal.

Your caution is justified.

I'll leave the colourful language to the 'gentlemen' over there, they are so much more adept at it.


----------



## Tinduck Racing (Jul 18, 2001)

> you are lead to believe


...lead? led? ..fuel additive related pun intended, perchance?

Take care ,Mycroft....great thread...

Jon.

P.S: Nitrox Hotshot 500ml...."power boost and injector cleaner"..claims to increase power by "up to 10%"...hehe...
.....contains over 50% Methanol, apparently... 
....your views on this product and it's claims would be most appreciated...keep up the excellent work.


----------



## Steve W (Jul 30, 2002)

Thank You Mr.M.........

the curtain is at last lifted.........(well partially raised).......

I will be proceeding very timidly with Tol' use (AB-use?:smokin: ),
but, sounds almost like an 'all-ups-no-downs' affair - if treated
with respect.

[ I won't be making too many comments in/amongst your threads,
as most of what your talking about goes WAY over my 'No.2 cut'.
I took O-level Chemistry AND O-level Physics AND passed both,
BUT, when the 2 are combined and weaved amongst engine
internals.......I'm lost !] 

Yours, Steve.


----------



## Mycroft (Apr 13, 2002)

If you proceed Steve, then please post your results on this forum, I know the 'other place' will get it, but a first hand account here would be appreciated, good or bad, we/I would like to know.

Good luck and be careful.

Regards.


----------



## alex h (Mar 11, 2002)

Apologies for diluting the Skyline focus of this thread but...

I think IanC and I on the Supra list both agree that it sounds better and feels smoother especially the idle. This is all probably down the ignition not having to retard itself so much.

If you haven't used Tol before put it in and let it settle - reset the ECU - fire it up - let it do its idle hunt and settle on a (roughly) 600 rpm idle, then take her for a spin.


----------



## Mycroft (Apr 13, 2002)

Alex post a link to your Octane thread, i'm sure everyone here would like to share IanCs' and others 'contribution' to the discussion.

If this is difficult I have copied all of it, it is not very big, and perhaps we could put it in a thread all of its own.


----------



## alex h (Mar 11, 2002)

I can't remember which thread on Toluene you mean, sorry, our most recent chat about it was over lunch so that kinda rules out posting our ramblings!

There have been loads of threads on fuel and octane boosting (and now octane holding) on the mkivsupra.net/bbs site everyone is free to read them.


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## Mycroft (Apr 13, 2002)

Let me help you, this one particularly caught my eye.

http://supra.highspeedhostinggroup.net/public_html/vbb/showthread.php?threadid=2440


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## alex h (Mar 11, 2002)

Chris's post is the one to read...nice to see some real race proven results of modern pump fuel.


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## Mycroft (Apr 13, 2002)

Just a pity that it took 3+ years, but it IS a good contribution.


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## I Wish (Aug 2, 2002)

How about this link ?
I believe this is what is in the NF bottles..

http://www.gtatech.com/


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## Mycroft (Apr 13, 2002)

I wish you would post your real name and include an E-mail address otherwise I feel like I'm talking to a ghost. Sorry if that sounds testy, I don't mean it to be.

Anyways up, that IS an interesting link and describes (probably better) the interaction of Iso-parafins almost exactly as I did earlier in this thread.

One of my guys called the action of Iso-parafins as a kind of petrol-brakefluid, not a description to taken too seriously but.

It does sound like NF I agree.


----------



## Steve W (Jul 30, 2002)

Just found on Miller Oils 'UK' site they do "Octane Plus".

They _claim_ (on the site) an 'average' of 'up-to' 1.6 *RON* 
increase and example there 95-to-97 & 97-to-99 (I think it was 99)
[ It specifically said RON and gave the eg's ! - hard to
prove/disprove I suppose ? ]

NOT saying I believe it, just quoting.

That would be VERY good for any 'bottle', from your posts ?

Any knowledge of . . . . (would make a good standby for when Tol'
not available !?)

Didn't see how big the bottle was - or how much....
(probably 5Litres @ £30 or some' stupid - might actually do it THEN - eehh ? )


----------



## nitro (Jun 27, 2002)

STEVE W
Here is your answer to the "toluene bit"!!!
If you are using a 10% add of toluene then you add 1 ml per litre of the Nitrous Formula Race.
If your using 20% add of toluene then you use 2 mls per litre and 30 % of toluene then 3 mls etc!!!etc, etc
If you get up to 15 mls per litre then you should have between 700 and 800 bhp using 98 octane fuel as a base.
Hope this answers your question.:smokin: 
I think you'll find this mix a lot cheaper, safer (personal health)and easier to use than toluene and so much better on your engine.


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## JasonO (Jun 29, 2001)

Mycroft,

In another thread not unrelated to this one, you commented on the CV of the JET brand of PUL.

What if any observations did you make on that particular brands RON and subsequent effects on detonation.


----------



## Steve W (Jul 30, 2002)

Nitro...

What/Who is Nitrous Formula Race ? ?

I was asking about MILLERS "Octane Plus" !

1ml per Litre ? That's only ~ 50/60ml per whole tank ! !

WHAT is going to raise octane levels significantly at THOSE
sorts of concentrations ? ?

Steve.


----------



## nitro (Jun 27, 2002)

STEVE W

Perhaps you had better read your thread again.
You didnt ask anything about "Miller's" but made a statement!!!!! Here is what you ACTUALLY asked 

"Any knowledge of . . . . (would make a good standby for when Tol' not available !?) 
Didn't see how big the bottle was - or how much.... 
(probably 5Litres @ £30 or some' stupid - might actually do it THEN - eehh ? )"


So re-read my thread and you have the answer and if you havn't heard of "Nitrous Formula Octane Booster's" it would be a very good idea for you to know some more here's the address.
www.nitrous.com.au

One thing i have to say is your very good at maths :smokin: 
1 ml per litre IS 50/60 mls per tank!!! Thays all you need its the CHEAPEST Octane Booster on the Market that REALLY WORKS !!
per tank / increase and best value money can buy 
And as i said much safer for your health !!!!!


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## Steve W (Jul 30, 2002)

" Just found on *Miller* Oils 'UK' site they do "Octane Plus". 

They claim (on the site) an 'average' of 'up-to' 1.6 RON 
increase and example there 95-to-97 & 97-to-99 (I think it was 99) 
[ It specifically said RON and gave the eg's ! - hard to 
prove/disprove I suppose ? ] 

NOT saying I believe it, just quoting. 

That would be VERY good for any 'bottle', from your posts ? 

Any knowledge of . . . . (would make a good standby for when Tol' 
not available !?) "

Nitro.....

I DIDN'T actually mention anything BUT Millers, until right at the end ! !

I *DIDN'T* ask ANYTHING about 'Nitrous Formulas' ? ? ?

How many *RON* (NOT points) do they claim for that ? ?

Steve.


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## nitro (Jun 27, 2002)

STEVE W
The Question that you asked was may i quote !!!

"Any knowledge of . . . . (would make a good standby for when Tol' 
not available !?) " 

So i was giving you an alternative to toluene at the rates i quoted in my thread.

THE ALTERNATIVE IS NITROUS FORMULA OCTANE BOOSTERS.

You have now asked another question and here is the answer plus some extra information for you.

Every 10 % of toluene added by volume increase's the octane by 1 or it increase's the octane by 10 points.
so if your adding 20 % by volume of toluene then you will get a 2 octane increase or 20 points 30% by volume 3 octane increase or 30 points !!!!
SO answering your question on an alternative to toluene is NITROUS FORMULA OCTANR BOOSTER !!! pretty simple And ive already given you the rates to use in the previous thread.

But you have asked ther questioon on RON increase's well here is the answer to that.
Under the ASTM D2699 to get an octane number increase then here are the results.
Nitrous Formula Octane booster base's the increase (label increase) on 60 litres of regular 92 octane petrol. not 10 or so litres like most ,
If you look at the web www.nitrous.com.au then you will see the various bottles that are avaiable and the RON increase's.
The only octane booster company to actually talk in RON and not points,units or numbers.

so re-read my threads again and hopefully it becomes easy for you to understand


----------



## Mycroft (Apr 13, 2002)

Went to Stanlow refinery to get more info on Optimax, I'd like to thank Nick Harris for getting me through the door. grateful mate.

Some interesting stuff going on with Opt. getting past the chaff and finding the grains is not easy, but my view is this, and I am only using what I know and not actual facts.

The base for Opt is PUL, but it is treated very differently from the other fuels, taking out some of the denser compounds in the final cracker (which they tell me is only used on the opt) as the fluid moves along the process they heavy stuff is replaced with manganese which has been compounded with either Xylene or Toluene (I think the former) further additives join the party and we get opt. asked whether they understood that people are putting things like NF in their opt, the response was simple, (I am paraphrasing) 'Why bother, we don't spend millions on doing this just to get the same effect as a tin of 'off the shelf' stuff, if you want to do that then just use SUL and play games with that'

I smiled at that, went off and enjoyed a very good lunch with Nick.

EDIT.

Nick owns the best Supra I have ever driven, a beautifully powerful car, a true Twin turbo job, midrange to die for, 2500 to 4500 it is so strong it hurts. A glorious motor.


----------



## swan (Aug 10, 2002)

Mycroft, I'd appreciate your input on two issues:

Mixing 102.6 leaded racing fuel with unleaded 93 (believe it or not that's all we get...) - ignoring damage to catalysts, etc. is this a good way to increase octance? If you mix 50/50 will you get 97.8 or does the leaded/unleaded mix not work that way?

I've been told that a 50% methanol, 25% Tuluene and 25% Xylene mix gives a 108.25 octance rating. Is this correct and what is your opinion on mixing 5l of this into a tank?

Thanks in advance.


----------



## nitro (Jun 27, 2002)

MYCROFT
I admire the effort that you are putting into this thread with the research etc you have shown.

Your last thread just confirms what i have been trying to say since i first started so im very thankfull for you to back me up.

Your visit to the refinery to come away with the conclusion that octane boosters do work is very encouraging to say the least. Conformation from the refinery point of view that they need and use octane boosters is even better make optimax.

Well Done, Glad you enjoyed your lunch.
:smokin:


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## Mycroft (Apr 13, 2002)

Hmmm, well, that is a nice spin on my findings, but not quite the real message.


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## bladerider (Jun 29, 2002)

this is an absolutely fascinating thread...ive read it about five times over, just to get into the chemistry.....

I wasnt going to post anything as i have nothing to add.....as im not a petro-chemist.

however, without wanting the force of the aussie longue-lash to come down upon me i have two questions...

1....is it me or are several people in here employed/sponsored ny octane booster companies or their distributors.....it just seems that theres alot of vested interest in some posts...

and 2......why are you making it sound like you are the driving force behind all this nitro??.....to quote "your (mycroft) last thread just confirms what i have been trying to say since i first started etc, etc"

If anyone deserves credit for knowledge, explanation and motivation for this thread i can think of only one person........and i have never met him or know him......but he seems ok to me!!

well done Mycroft for all your hard work......hopefully a conclusion to all this will be found one day!!

James.


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## Mycroft (Apr 13, 2002)

I admit to having a few thousand shares in ESSO. (inherited)

But I have tried to remain unswayed by this fact.:smokin: 

I know what the main protagonists on here do, and have made myself aware from the moment this thread started to become the monster it now is.

A final 'answer' is somewhat elusive, but I think we have all advanced our knowledge of exactly what happens in that cylinder, anyone reading this thread will find one nugget of info that is new to them and all of us at least plan to up the power of our motors and the more we know the better equipped we are to make a right decision on what we go for.

In the end 'you pays your money and you makes your choice'.

PS.
This thread has been translated for at least one Japanese web site and I have received e-mails from all over the World about this subject, this forum has been quoted on damn near every Continent on the Planet.


----------



## nitro (Jun 27, 2002)

James 

answer to question 1

If the opinions on here do happen to reflect wether or not they do have an interest or sponsered does it REALLY matter.
I have tried nearly all the fuel additives on the market and found couple that do work so does one keep it to himself or tells others. 
After all thats what this site is all about sharing information !!!!

Question 2
Im not taking any credit for what Mycroft has done.
AS i said he's done a great job !!!
So i gave credit where it was due WHATS WRONG WITH THAT???

I voiced an opinion which stirred things up, got people talking, dug deeper into this area and found out many different opinions and have come up with some great answers.

This o b thread was going before i came on here so i dont see how i could be the so called driving force.


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## Ray SA (Jul 26, 2002)

Mycroft hello , glad to see this thread is gaining momentum again , was getting a little quiet lately . 

I have switched to 102.6 RON racing fuel . Fullstop . Only costs 25% more .

Wouldn't it be nice if the fuel company could supply the diffence in a bottle !

Enjoyed your report on Nick's Supra , think thats what we all want is a car that hurts when you accelerate .

Ray

James dont take Nitro too seriously I'm sure his intentions are not as he is received . I have found all people of differing nationalities display challenging characteristics and require effort to get to know .

Just trying to ease the flame front on that one .


----------



## Ray SA (Jul 26, 2002)

Oh forgot to mention thats 100 MON as well .

Ray


----------



## Mycroft (Apr 13, 2002)

Ray that is probably the best thing to do, I feel under qualified to design or help design a fuel for your environment.

Jun modded Supe properly set-up = shattering midrange the big 3ltr with 2 turbos that work in unison is perfect for that, the 2.5/2.6 six in my car and in the Skyline is more suited to 3000+ thats when they sing a louder, sharper song.

Regards
Iain, the hopelessly addicted petrolhead.


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## Ray SA (Jul 26, 2002)

Apologise if it sounded I was giving up on you Mycroft , not the case just got over my fear of load lead racing fuel after some friends having used it for up to 80 000km's without a wimper from the cats or lambda sensors . Its really more practical than travelling 300km's to fetch 97 and try and fix it , but was an interesting thought . The car has experienced a marked improvement in performance on the road tested against another car using a lower octane , so I'm pretty satisfied . I was rather looking forward to the groups conclusions on Tol / Xylene as we both know it works . 
My interest in racing fuel is how balanced it is , and I'm rather naively thinking it possible to convert standard fuel to racing if the composition of racing fuel is known .
Got some of that racing fuel in my eye whilst pouring it and was surprised it didn't sting too much ...

Cheers .
Ray


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## Mycroft (Apr 13, 2002)

swan said:


> *Mycroft, I'd appreciate your input on two issues:
> 
> Mixing 102.6 leaded racing fuel with unleaded 93 (believe it or not that's all we get...) - ignoring damage to catalysts, etc. is this a good way to increase octance? If you mix 50/50 will you get 97.8 or does the leaded/unleaded mix not work that way?
> 
> ...


First question, no don't do that, the metals carried in the leaded will effect the valve seats badly.

That mix works nicley and does not flare, it is less good than the mix I outlined earlier and you can go up 15/20% without too much fear (incrementally, so as to not 'shock' the motor) but it means a rather prolonged contact with the cocktail than you would really want.


----------



## David_S14 (May 4, 2002)

*Top thread guys*

Just a post to say that I've enjoyed reading this thread alot. It is good to see forums having a discussion on difficult topics and not resorting to the "handbags at five paces" approach.
There's a lot more to these infernal combustion engines than first meets the eye 
Keep it up


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## 200sx Lurker (Aug 17, 2002)

Wahay ello dave_s14.

Great thread chaps - oh where can i get some isopropyl alchohol from? Nuthin to do with cars but i need some.

Anyone selling callipers?


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## swan (Aug 10, 2002)

---
First question, no don't do that, the metals carried in the leaded will effect the valve seats badly. 
---

Interesting, the only side effects I was aware of was premature replacement on the spark plugs, lambda sensor and damage to the cats.

---
That mix works nicley and does not flare, it is less good than the mix I outlined earlier and you can go up 15/20% without too much fear (incrementally, so as to not 'shock' the motor) but it means a rather prolonged contact with the cocktail than you would really want.
---


Are you referring to :
"I found that Toluene with about 2% iso-propyl to be best at around 7% by volume of the fuel used. "?

Is this mix more/less carciogenic than the one I listed? If I were (hypothetically speaking of course , to get a batch mixed up would I need more details on a particular iso-propyl to use? With your mix that would mean 4.2l to a 60l tank, correct? Why is it less good than the mix above? In addition, would your mix even at that concentration not be more damaging on the fuel lines?

TIA.


----------



## Joe (Aug 28, 2002)

Mycroft,

I'm a new user in this forum and have registered in this forum cause I found this thread very very interesting ! 

I have read that toluene have a negativ impact on rubber and several plastics. 

Is'nt the flexible part of the fuel pipe partially made of rubber or plastics ?

Have you ever checked your fuel pipes after having used this Toluene mixture ?

How about the tank itself ? Is it in danger if I use Toluene ? Does this mean that I have to burn this mixture asap ?

TIA (Thanks In Advance) for your answer

Greetings from Switzerland,


----------



## Mycroft (Apr 13, 2002)

Yes this was a problem with some items at high levels of Toluene, but since about 1989 when many of these things became part of the make up of 'normal' fuels the materials used in the manufacture of our cars is quite tolerant, although I wouldn't like to run 30% for every day use for a year or so.

Thankfully, the stuff is just too hard to get hold of to do anything like that, 7% has been used in my car for a number of years now and my regular checking of the system has shown no problems at all. 

I get my Iso-propyl from Boots the Chemist,:smokin:

(Edit, the girl behind the counter probably thinks I'm a wino.)


----------



## adair69 (Aug 29, 2002)

Just got this thread linked onto the Scoobynet site, absolutely fascinating! Not being too chemically minded and really only understanding the carcinogenic properties in fuels being responsible for 
A/ the VAT man wanting his cut and 
B/ The change in the make up of fuels 

I am truly awestruck in both the way this forum has been run, and the considerable research and effort which has been placed on this topic, which for the most part is incredibly crucial for the cars we all drive. Thank you for trying to simplify it for us "Lay men"

I have one question which I may have missed the answer to, and if so I apologise in advance.

If the fuels are liable to losing "rating" for want of a better expression. Do you have to mix the "Mycroft Elixier" (Tuo, alcohol etc)at the same time as it is used, or could you mix and store a 
quantity which will retain its potency for a period of time?

And thanks again for the Tutorial!!


----------



## Hugh Keir (Jul 25, 2001)

Interesting link from B.P. Australia. 

http://www.bp.com.au/fuelnews/PET0605.pdf 

Probably re-stating stuff that's been talked about earlier but it's good to see comments from an oil company. 

" Increasing octane does not increase power" 

"All petroleum based products produce similar power" 

"Methanol is the only readily available fuel that produces any significant increase in power over petrol"


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## Steve W (Jul 30, 2002)

It's not the actual increase in Octane Rating that _gives_ you
more power - it's because with higher Octane you can alter other
factors {Boost, Timing etc ?} to PRODUCE the power, and the
fuel will be less likely to give combustion problems (pinking,
detonation ?).

OR, am I WAAAYYYYY OFF ? ?

Steve.

[ the number of times people at work have said "YEH, I tipped a
bottle of booster in me' Mini and it goes like stink" - it _may_ be
smoother etc. but it's unlikely to be producing any more GO unless
they've altered something else - OR, it SHOULD have had THAT
octane in it in the first place - ie. it was running too low an Octane
_before_ adding the booster !] ?


----------



## Mycroft (Apr 13, 2002)

Nope, you are right on both counts.


----------



## Steve W (Jul 30, 2002)

JESUS ! !  ('scuse 'taking-in-vain')......

You mean I actually (partially) understood something ? ?

I don't believe it.



[ I'll give you the fiver later Mr. M  ]


----------



## swan (Aug 10, 2002)

*Mycroft - clarifications please*

'ello Mycroft,

I realise I didn't address this to you:

--- 
First question, no don't do that, the metals carried in the leaded will effect the valve seats badly. 
--- 

Interesting, the only side effects I was aware of was premature replacement on the spark plugs, lambda sensor and damage to the cats. 

--- 
That mix works nicley and does not flare, it is less good than the mix I outlined earlier and you can go up 15/20% without too much fear (incrementally, so as to not 'shock' the motor) but it means a rather prolonged contact with the cocktail than you would really want. 
--- 


Are you referring to : 
"I found that Toluene with about 2% iso-propyl to be best at around 7% by volume of the fuel used. "? 

Is this mix more/less carciogenic than the one I listed? If I were (hypothetically speaking of course , to get a batch mixed up would I need more details on a particular iso-propyl to use? With your mix that would mean 4.2l to a 60l tank, correct? Why is it less good than the mix above? In addition, would your mix even at that concentration not be more damaging on the fuel lines?


----------



## Mycroft (Apr 13, 2002)

Leaded fuel mixed with unleaded fuel effects the performance of lots of things, Japanese cars in particular have been using unleaded for a very long time and the alloys chosen for many components just are not lead tolerant.

I have only done the work necessary to be confident that my own mix works safely, 7% gives me the ability to advance my ignition enough to get a good bit of extra power safely, I have always erred on the side of caution and will continue to do so, the mix you describe has been used and documented on the net and if you wish to proceed then fine, but as always take great care.

The carcingenic properties of all this stuff can be found at numerous websites, toluene and Xylene are not considered carcinogenic, you must check the others for your self and read the warnings, which are comprehensive, carefully.

If in doubt---check it out.


----------



## adair69 (Aug 29, 2002)

Mycroft

Following my earlier post, My curiosity is sufficiently aroused to try your mix, but where can you buy Toluene? And as I asked earlier has it got a shelf life?

Thanks


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## swan (Aug 10, 2002)

*Hazards of Toluene*

For those interested www.toluene.org and TOLUENE (AMOCO/TOTAL)


----------



## Guy (Jun 27, 2001)

*Viewings*

Over 10,000 viewings of this thread, just thought I'd bounce it back to the top......

Guy


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## dan0h (Jul 26, 2002)

*Re: Hazards of Toluene*



swan said:


> *For those interested www.toluene.org and TOLUENE (AMOCO/TOTAL) *


I just used to slop it around in a measuing jug making Race fuel when I started at Abbott Racing...


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## bladerider (Jun 29, 2002)

*exposure to toluene may result in brain damage*

lol

Thats why you're such a gibbering, twitching, slack brained neanderthal Mycroft. Hardly capable of stringing together a coherent sentence !!!! lol  

Do you just rinse, or do you gargle as well??......I think I could do with "brain damage" like yours matey !! 

Am I increadibly obtuse or is toluene the last bit of TNT.........and why not just mix a bit of the liquid form of this with some petrol to really get the old motor racing??

Only kidding Mycroft......keep up the good work !

James...............


----------



## SP 325i (Oct 10, 2002)

Sorry to crash this thread but there was a link to it from a BMW forum.
I am also a Chemist so I have read all 13 pages with interest. You guys with turbos, high boost etc have a lot more detonation problems than the NA cars but being into a certain French hot hatch I thought I would add the following insights.

The car was a 1991 205 1.9 Gti. This has a very basic fuel management system. The car was designed to run on min 97 RON fuel. Immediately if the fuel is of lower quality or 95 RON UL is used "pinking " under load can be heard so the ignition is retarded (this has to be done manually remember). The guy (an old school race mechanic) uses a stethoscope to listen for the noise as the timing is changed. I presume this is just a manual version of the knock sensors and then the ECU takes care retardation.
Using this method on old 98RON would get back to OEM spec and Optimax allowed the timing to be slightly in advance.
This is a real world example of "the Mycroft theory", if I am wrong please correct me.
I am now into BMW ownership and have decided to use Optimax instead of 95UL. Reading "being guinea pigs etc " has started to worry me though. I use it for the low sulphur content (BMW owners are paranoid about NIKASIL bore wear) and cleaning properties.

Good thread please keep it going.

Steve


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## Mycroft (Apr 13, 2002)

Brought over from another thread on here as it maybe pertinent to this discussion.

This leads on from the Octane booster thread to some extent, so for clarity I'll simply outline how a sensor of this type works; 

The oxygen sensor utilises the "Nernst effect." Nernst's law measures the voltage between two materials in close contact, one of which is a known constant. When the sensor reaches a temp. 640degrees F ±25F, it produces a voltage which is interpreted by the ECU and adjusts the fueling to suit. 

The outer shell of the sensor is Zirconium Oxide, this material is very sensitive to contamination, think of a nice piece of polished alloy and how easily it will absorb the oil excreted by you skin, well ZircOx will take up all those additives in petrol, but for the most part they don't effect it too badly, but Opt and all those OBs' do contain contaminents and if over applied or applied constantly (as in using Opt continually) the voltage engendered is not as it should be, Citric acid cleans ZircOx perfectly, the acid actually cleans down into this 'rough' surface, we are talking very small scale here, so to the hand it is quite smooth. 

Lead, from fuel screws them, Phosphorous (Opt, and most OBs') does the same only slowly, If your turbos have ever blown their seals and blown smoke out the back, the phosphorous in that burn out will kill it fairly quickly, you should always replace the sensor if this has ever happened to you.


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## dan0h (Jul 26, 2002)

*Broquet Fuel Catalyst*

Mycroft...

As my car is arriving soon I've been looking into ways of getting around having to use Opt or SUL and have been pushed in the direction of the "Broquet Fuel Catalyst" (http://www.broquet.com), apparantly it was used by Subaru UK to remove pre-ignition problems on early impreza's.

Can you confirm or deny the usefulness of these, will it work, or is it just garbage?!

Cheers,

Dan


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## SurreyPuma (Oct 14, 2002)

*Avgas*

Very simple and very easy! 
1.Obtain jerry can,
2.Proceed to a local airfield where they fly 'PISTON' engined aircraft.
3.Squat down under wing and look for fuel drain, which will at lowest point in wing.
4.Turn drain and empty fuel into can(May need a screwdriver but most are hand turnable)
5.Fill can, may take some time!!!

Piston engine aircraft fuel is blue in colour and 100 octane. I imagine u can buy it as it is taxable etc. There are also different grades of Avgas which go up too 115 octane, but ive never seen any.Maybe contact shell or some oil company, 115 fuel is purple colour!!
100 avgas aslo contains small amounts of lead so do not use on a cat car!!!

Have fun


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## dan0h (Jul 26, 2002)

I believe you've forgotton steps 6 & 7...

6. Replace destroyed cylinderhead and pistons in 6,000 miles.
7. Make a note never to use AvGas in a road car again.

I've heard all kinds of horror stories about AvGas and its long term effects on road engines. Maybe its just scare stories but I'm not going to try it in an RB motor until someone else does 

Good idea though


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## bladerider (Jun 29, 2002)

*your absolutely right dan*

lend me your car and i'll try it for you !!!

yer wimp !!!!! 

James..........


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## SurreyPuma (Oct 14, 2002)

*Avgas*

I cannot see the problem with using it as a one off. People mix it for use on jet skis and it keeps light aircraft flying with no problem. I know lots of people who use it in their cars, when i can i use Jet A-1 in my diesel and it makes no difference. All i can say is compare spec sheets on fuels!


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## dan0h (Jul 26, 2002)

A-1 Jet is basically parafin though so no harm to a diesel, its just the long term issues I was concerned with ... Although as you say for one offs its probably not an issue... I'll still wait until someone else does it to an RB though


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## R32BigSly (Oct 17, 2001)

*Avgas!*

Surreypuma,

Was reading you post with a lot of interest! and you say that avgas does contain a small amount of lead, does this mean i cannot use it in my motor as i have sensors tapped into the zorst for afr, egt etc ect and i was told that AVGAS will put a "coating" on theses sensor and render them useless??

I do not have a cat on the car BTW....

Many Thanks

Stu


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## Mycroft (Apr 13, 2002)

Please, if you have a Japanese car made since 1987 then don't even think about fuel with Lead in it, you are playing russian roulette with you engine and your wallet.


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## R32BigSly (Oct 17, 2001)

*Gambling!*

Cheers Iain,

Will keep my gambling to a wed & sat nite max then!!

Stu


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## dan0h (Jul 26, 2002)

Mycroft said:


> *Please, if you have a Japanese car made since 1987 then don't even think about fuel with Lead in it, you are playing russian roulette with you engine and your wallet. *


Thats pretty much what I heard ... what do you think of the Broquet thing though Mycroft?


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## R32BigSly (Oct 17, 2001)

*Additives!*

Dan,

When reading the spec sheet of Gary's HKS R33 on his website!! i am sure it said something about him using the Broquets to help raise the octane!!

Stu


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## dan0h (Jul 26, 2002)

Stu,

Ahhh excellent .. I'll look a bit further into it then ... I'm just not really a fan of things that "Just work" I like to know how and why! Was hoping Mycroft could shed some more light onto the subject...

Cheers,

Dan


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## Mycroft (Apr 13, 2002)

I sent a request for information to Broquet but have nothing back as yet except the usual non scientific guff, but will keep trying.

I might buy some and test the stuff myself when I have time.


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## dan0h (Jul 26, 2002)

Mycroft,

Thats cool .. I'd be interested to hear the results, certainly on the web I cant find a bad word said about it ... everyone reports power and economy improvements, sounds too good to be true though... 

Cheers,

Dan


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## R32BigSly (Oct 17, 2001)

*Interesting??*

Dan,

Is there a specific site i could have a look at please??

Just curious thats all mate! as i have used virtually everything else available or not on the market!!

cheers

Stu


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## Philip (Jan 17, 2002)

I understand that all Impreza P1s and UK 22Bs were delivered with two Broquet in-tank pellets, put in there by Prodrive or IM. Haven't seen any independent proof that it works though.

Phil


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## Philip (Jan 17, 2002)

http://www.broquet.com/

http://www.broquet.com.sg/


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## Blow Dog (Sep 4, 2001)

The Subaru community was 'encouraged' to use the Broquet after knowlegde of Subaru placing broquet into the tanks of all the P1's sold.

Lot's of energetic enquiries and tests were made with no firm results. As far as I know it's since been forgotten.

This is an interesting thread I've dug up.

http://www.scoobynet.co.uk/bbs/thread.asp?ThreadID=8554 

Cem


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## dan0h (Jul 26, 2002)

*Broquet*

Stu,

Those two links posted by Philip should tell you as much info as there really is on the web. I'm hoping that if Mycroft does some analysis on it that we may get a little more technical stuff that might go some way into explaining how and why it really works.

The link Cem posted is well worth a look.

Cheers,

Dan


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## Mycroft (Apr 13, 2002)

I may be able to kill this quite quickly, whilst talking to one of the 'senior' lab guys here, (old people can be irritating but they have a vast knowledge base and SHOULD be respected for this)
anyway this coffindodger gave me the rundown on this stuff, the short answer is 'Don't bother'.

Fuller and very boring answer;

Broquet used to work, in fact it worked brilliantly, but that was when there was something called 'pool' petrol which was basically 70oct stuff with a CV that barely put it over paraffin, when the original Broquets were put in this they made the fuel a slightly higher octane and made this rather poorly refined fuel burn better, as the fuel quality went up after WW2 they became less and less effective (at one point petrol in this Country was so pish-poor that just stuffing Moth-balls in the tank helped the deflagration) it was reformulated later in the 60's but was never able to keep up and the general consensus is that the material is at best 'mostly harmless' at worst, 'worthless'

I shan't be wasting my time taking this any further.


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## dan0h (Jul 26, 2002)

Thats all I needed to hear ... Thanks Mycroft!


----------



## Steve W (Jul 30, 2002)

*edit-"SORRY Mr.Mycroft - didn't stop to read your last reply ! ! - disregard following:- "*  



> ......Another major advantage of using the catalyst in countries where unleaded petrol is replacing, or already has replaced, leaded petrol is that Broquet will generally allow the safe and efficient use of unleaded petrol in all petrol-engined vehicles......


SO, it must ADD a 'lead'-type lubricant...ie. is it as harmful as
Leaded fuel to Jap' engines ? ? (non-cat'-affecting ?)




> .........also removes, and then inhibits, the build-up of carbon deposits, waxes and gums that normally form in the combustion chamber.


? ? ? All we need to know is HOW....if all-it-is is lumps of metal,
how does it achieve cleaning of combustion chambers ? ? ?


NEED THOROUGH DESCRIPTION OF WHAT/HOW IT DOES
WHAT IT'S SUPPOSED TO DO.......

Yours, Mr. Sceptical, (Fat Steve).
[ps. I'd LOVE to be proved wrong, BUT, they never tell you HOW..]


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## Syed Shah (Feb 20, 2002)

Mycroft said:


> *Please, if you have a Japanese car made since 1987 then don't even think about fuel with Lead in it, you are playing russian roulette with you engine and your wallet. *


Why exactly do you say that?

Leaded 116octane fuel is used in the states by Supras, Skylines etc, with no harm at all, all it does is shorten the life of your O2 sensor to a few thousand miles, nothing to the engine, in fact, it is better for the seals etc.


----------



## dan0h (Jul 26, 2002)

I'm pretty sure the US idea of 116 octane differs from ours, I think we display Research Octane Number (RON) and they just show Pump Octane .. or the other way around


----------



## Syed Shah (Feb 20, 2002)

Nope.

There is MON and RON, we show RON, the highest of the two numbers, they show an average of MON and RON.

So to put it another way, their 93octane fuel is like our Optimax.


----------



## dan0h (Jul 26, 2002)

Hmmm .. hopefully Mycroft can shed some light on this then...


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## Mycroft (Apr 13, 2002)

Ahh, my 'pal' Shed Syah,

Longevity, to an ant a day is a huge part of its existance, to a tree it is just a small part of a season, a season is a small part of a trees life.

To have a car run on 116oct leaded fuel means that it is something out of the ordinary, it has been rebuilt, like as not and it will also be owned by someone trying to extract the very last ounce of power for an impressive dyno run and as your friend Chris Wilson is apt to say, 'it ain't real world numbers' someone who is going down this route will not baulk at rebuilding the motor often.

Lead effects all manner of things, valve rotation being the one that does the most damage in the end, there are many books on this sort of thing, have a look at Moderns oils also they are very badly effected by even the most minute trace of lead, just a little flooding and that expensive synthetic oil is gonna 'curl' it locks the lead within itself and there is formed a precipitate in the oil, just waiting to block one of you arteries.

There are many reasons to do with metallurgy also.

Fuel ratings
RON--- MON--- PON 
90----- 83------ 86.6 
92----- 85------ 88.5 
95----- 87------ 91 
96----- 88------ 92 
98----- 90------ 94 
100--- 91.5---- 95.8 
105--- 95------ 100 
110--- 99------ 104.5 


We in the UK use RON others PON
OPT with a (debateable) Oct of 98.6 RON is 95 PON.
SUL with 97 RON is 93 PON so #their 93octane fuel is like our Optimax# is wrong..


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## dan0h (Jul 26, 2002)

Mycroft said:


> *Longevity, to an ant a day is a huge part of its existance, to a tree it is just a small part of a season, a season is a small part of a trees life.*


Beautifully put Mycroft. Once again your wisdom clears a path through the fog of mis-informaiton!

Cheers,

Dan


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## TOKYO (Jun 28, 2001)

*Mycroft*

Are you a Vampire? 

You've gotta sleep during the day to come out with these sayings this time of night    .

Plus you do scare me sometimes    .

glen


----------



## Mycroft (Apr 13, 2002)




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## somberg (Jun 27, 2001)

hehe  sniffed too much toluene have you


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## Mycroft (Apr 13, 2002)

Nah, sniffin's kids stuff, 'on the rocks' is the way to go.

Edit, this thread is getting WAAAYYYYY too many hits, nigh on 12,000, poor (literally?) Cem.


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## TOKYO (Jun 28, 2001)

*SPOOKY*

Rights thats it, I'm off to bed  .

glen


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## Syed Shah (Feb 20, 2002)

Mycroft, 

Saying that lead is bad for engines and valves goes against everything I've ever heard, some from very knowledgeable people, which in my mind, cancels out what you have said.

As for 116octane fuel only being used in extreme vehicles, well, a lot of people in the states run this fuel in 'BPU' Supras, when at the track etc. Not the most extreme of setups.

BTW, you are simply being pedantic about the octane ratings, 93vs94 is not a huge amount of differnce, and the point still stands.


----------



## somberg (Jun 27, 2001)

Syed Shah,

I don't think you quite understand the concept of searching the limits of an engine. In the quest for max power output, you want to find the limit where detonation starts (and consequently engine life is shortened  ). As you can (or should have if you will) read from various other posts on this board, and I'm sure you can get this verified by your expert friends, this also depends on the octane rate of the fuel used. Using fuel with an octane rate lower than used to program the ECU (even if it "only" differs 1 octane), will (dependant on the ECU used) in the best case cause loss of power and in the worst case destroy your engine.

Andre.

BTW can you explain what the heck BPU is ?


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## Syed Shah (Feb 20, 2002)

Basic performance upgrades (Tm  ) Like decat +exhaust and BC etc.

As for your post, well I dont think any stock-turboed skyline would detonate on US 93octane.

As for the ECU mapping, the ECU 'adapts' to the fuel used, ie if too low, timing will be retarded causing power loss, but use of a very higher octane fuel (leaded or unleaded) will result in a power gain due to timing not being retarded.


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## somberg (Jun 27, 2001)

If that stock turboed Skyline has a std ECU mapped for Japanese fuel (100 oct), then it probably will detonate, yes.

Re. use of a "very higher octane fuel": if your reference point is the octane rate of the fuel used to map the engine, it will not result in more power, but merely "not less power" due to the timing not being retarded.
Note that the means used to detect detonation in most ECU's (like the ones in the Skyline) is done with piezo-effect det sensors. The electronics hardware and software with which the signals are analyzed, are not very elaborate. In other words, it's quite an "over the thumb" method, meant to protect the engine from destruction. Timing is retarded quite drastically, resulting in quite some power loss. That's why you don't really want to use 97 octane if your ECU is mapped for 98.
The ECU's as such are basically open loop systems. Next generation ECU's will be based on closed loop control, using det sensing techniques ("ion sensing") that go far beyond the possibilities of the piezo sensors. See also earlier on in this thread. Result will be better adaptability of the engine to various octane fuels, better fuel economy and less pollution.


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## Syed Shah (Feb 20, 2002)

Well, not sure about Skylines, but in Supras, due to the ECU 'learning' the fuel octane, then a better octane will mean more power.

This relates to Mycroft's post a while ago about toulene reducing his 1/4 mile times by over a second (this much of a difference is unrealistic IMHO). This would be due to the car making use of the higher octane.


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## Mycroft (Apr 13, 2002)

#Mycroft, 

Saying that lead is bad for engines and valves goes against everything I've ever heard, some from very knowledgeable people, which in my mind, cancels out what you have said. #

Interesting...do me and all of us a favour, run you car on unleaded for the 3 months, then return with you 'findings' please do this if you can. I will be quite happy to eat my words if I am wrong.

Try also running your car on 116oct but before you do take readings of your timing before 116 and after, then post just how much your ECU has 'learnt' about its rating. this will also be interesting, I have de-programmed a few Toyota ECUs' and they don't quite behave in the way you describe.

I have to advance the ignition by deceit, the ECU doesn't do this, it can retard and can back off from maximum retardation but it can never fully recover the Factory settings, that is why they have a simple 'reset' mechanism of removing for 30secs the fuses, this would be un-necessary if the system was 'fully-recoverable'

As for the pedantry, you maybe right, but accuracy is important here, so if I correct you it is for the sake of accuracy, this thread is read all over the World and 'guestimates' just don't cut it here.


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## Syed Shah (Feb 20, 2002)

1 second, 3/4 of a second, eirther way, too much for JUST adding toulene. 

De-programming Toyota ECUs??? For which Toyota?


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## somberg (Jun 27, 2001)

Syed Shah

Why do you think that ?
Do you believe it's due to for instance the removal of an ingrown toenail ?


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## dan0h (Jul 26, 2002)

somberg said:


> *...Do you believe it's due to for instance the removal of an ingrown toenail ? *


LMFAO  

Perhaps if it were a really painful toenail it could have prevented the throttle being fully depressed?   

Nice one somberg ... thats the most I've laughed in quite a few weeks!


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## alex h (Mar 11, 2002)

somberg said:


> *Syed Shah
> 
> Why do you think that ?
> Do you believe it's due to for instance the removal of an ingrown toenail ? *


Geeez have you seen the results of this mod....I wiped 2 secs off my 1/4...and there was me thinking the body work or engine were ripe for weight reduction....

LMAO!!....


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## Syed Shah (Feb 20, 2002)

As soon as you supply me with some 116octane leaded race fuel.


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## Mycroft (Apr 13, 2002)

Milton Keynes, has a little local airport and they sell 116oct leaded AVgas, go to it!

We await results.


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## Syed Shah (Feb 20, 2002)

AVgas has different properties to the leaded race ffuel used in US Supras etc, so no thanks. :smokin:


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## Mycroft (Apr 13, 2002)

Not very much my friend, the composition is basically the same.

The only difference really is the additives in the AVgas are not suitable for warm weather.

We had our first 'frost' last night and the days are colder so stop the excuses, put up or alternatively...


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## Syed Shah (Feb 20, 2002)

Well, just going on what i've read on the US forums, they use a lot of leaded race fuel, but do NOT recommend the use of AVgas.


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## Mycroft (Apr 13, 2002)

Mostly for the reason I have outlined, it is cooler now, the flash point and boiling point is now suitable.

I do understand your 'evasion' though, as within a month your motor will be ruined.

Leaded race fuel is for race engines which are built to a design with materials unaffected by it. Road cars are built to a price, the materials will always be selected with this in mind, Japanese engines have been designed since 1978 to run unleaded, lead has been 'out of the picture' for so long.

This 'diversion' has served a purpose though, please THINK before you POST.

End of. (As far as I'm concerned)


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## Syed Shah (Feb 20, 2002)

Mycroft,

Why not go over to www.supraforums.com and post your 'thoughts' there?


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## Syed Shah (Feb 20, 2002)

Do you remember the Fiat Coupe forum??? Does the name Nigel ring a bell?

A quote: 


If it was my kids you wiped out in the accident you are likely to have or cause one day very soon, I would merrily tie one of your bollocks to your mangled Soarer and the other (if indeed you actually have two) to my 355 and pull gently away. - Nigel 



http://forum.fiatcoupe.net/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=19;t=000204;p=4


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## Syed Shah (Feb 20, 2002)

Hmm, still keep an eye on the forum full of idiots? Sad indeed.

Its you with the issues.

Mods, please do delte this stuff, but not the previous things on leaded fuel etc, as that is all simply discussion.


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## Syed Shah (Feb 20, 2002)

Mycroft said:


> *. *


Your most genius post!


----------



## Steve W (Jul 30, 2002)

[ DELETED, AS IRRELEVANT (by author) ]


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## Mycroft (Apr 13, 2002)

There are various race fuels that are lead free and the Guy on your site to seek advice from is Chris Wilson, he (I believe) uses it so can probably supply you at a reasonable cost. He may even have some tolly kicking around. (for that little bit 'extra' when it's needed ;-)


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## Steve W (Jul 30, 2002)

[ DELETED, AS IRRELEVANT (by author) ]


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## Blow Dog (Sep 4, 2001)

This thread is too valuable to risk an irrelevant tangent.
Mycroft has contributed significantly to the discussion of Octane on this BBS, I'd be very grateful if we could keep the thread on topic and any personal discussions offline.

Keep up the good work.

Cem


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## Tinduck Racing (Jul 18, 2001)

[Posts removed as requested]


JonB


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## Gibbo (Nov 19, 2002)

Hi there

At the moment I am running a UK Honda Prelude 4th gen (1992-1996) 2.2Vtec.
It is completely std and at the moment I fill up with STD unleaded fuel.

I've have read most of this thread and have come to the conclusion that if I start filling up with Shell optimax or fuel from Fina/Elf/Total I might see a slight performance increase?

What fuel will be best for my car? If it's Optimax then fine, if it's the stuff Total/Fina/Elf sell then what is it called on the pump? Basically whats gonna give me the best performance and is there any risk of longterm damage?

Or will there be no improvement and therefore I should just stick with bog STD unleaded fuel?

Sorry for all the questions, just wondering if it's worth spending a few extra pence on fuel and what improvement and problems there might be?

Thanks.


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## Mycroft (Apr 13, 2002)

As far as I am concerned the jury is out on Optimax.

Shells' last foray into an exotic fuel 'Shell Advance' lead to its withdrawal and quite a few claims for new engines, if in a furhter 2 years no-one has claimed that their motor is dead as a result of Optimax then I'll use it, until then it's the T/F/E group for me.

(and a little tolly/xylene for those...special times)


----------



## Mycroft (Apr 13, 2002)

*Just when you thought that Octane Boosters and Optimax had gone away*

Well, some time has past on this matter and a few things have happened here and there regarding this whole subject and for the most part they have been of little or no interest to us here.....however....

In November I read a post from an Engineer from Aston Martin he had noticed over the past year or so that during the strip down and rebuild of the DB7 Supercharged motors and some of the more highly tuned V8's and pepped up 'Old' 6's that there seemed to be a problem with water in these motors, there was rust deposits on the plugs and even on the upper parts of the cylinder liners.

He asked for help as he had performed every conceiveable test he could think of to check for moisture, gaskets...the lot...finally he had returned to him a motor that he had built not long before, it was one of the first motors he had seen with this 'problem'.

This mans qualifications and experience in re-building engines puts him in the top league, he has been flown all over the World to re-build motors for Museums and Collections etc. A man of exceptional skill.

He kindly sent me a Spark Plug from this motor asking if I would kindly check if the brown spots on it were rust and some huge exceptional quality photographs (his hobby) taken with his Hassleblad.

At first glance no doubt about it this engine had a leak, a water leak, not a bad one but bad enough, the odd thing was that apart from the odd hard race and a precautionary strip down and re-build, these motors would run beautifully.

But again that is no surprise as we all know that water can be injected into any engine and in all cases about 0.3% power boost obtained due to the thermal expansion of the water into superheated steam, even better in turbos because of that and the cooling of the charge prior to ignition.
Normally however the explosion and steam never leave a 'deposit'
on anything unless the chamber is 'saturated' and that is a waterway/head gasket failure....none of these motors had this!?!

The plug and photos 'screamed' gasket failure the engines were not using water at all and they ran smoothly, some had been 'cleaned up' and returned just a few weeks later to be found with this 'condition' not one fluid ounce of water missing from the system.

Under a 400× 'scope everything changed....the 'tell-tale' brown rust had become a complex chrystalline structure of great beauty and in polarised light this jewel of a structure flashed and sparkled in a manner that no 'full sized' jewel ever could to the naked eye...I recognised the characteristics immediately.....this was not rust.......this was Manganese.

(Big string section of an orchestra some where behind me goes....Da-daa-Daaaaaaaaa)  

I now had a damned good idea as to what was happening.

I immediately made contact with our Engineer, who being a meticulous sort of chap had records of almost every detil of every spin of all the motors he 'owned' as he put it.

As he talked me through each car after about 40 minutes or so (yep, a telephone conversation that could have bored the pants off a frigid nun locked in a fridge in the middle of a frozen lake in the Arctic circle) a pattern emerged, all these cars had run Optimax and Octane boosters which is exactly as I suspected the moment I saw that chrystal structure.

Now I must emphasise that NO DAMAGE had occurred, a few very cautious owners had paid for a couple of very expensive re-builds.

This is why this thread has been revived..because almost all the contributors and many of the readers of this thread I believe are just that cautious and enquiring.

Moral..It may look like rust, it may seem like you are heading for a big bill, but if you use Optimax with a high Manganese Octane Booster then don't have a brown trouser moment, check everything first, perhaps a little less OB?

Regards.


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## Alan (Jul 1, 2001)

> but if you use Optimax with a high Manganese Octane Booster


I have been following this thread over the months since it was raised. 
Very interesting Mycroft 

In your experience which are the O.B. that have a high Manganese content 

Waiting in anticiptation  

Best regards Alan


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## Mycroft (Apr 13, 2002)

Frankly, I don't know!

Now despite the close monitoring of his engines, he is never there when they are filled with fuel/OB and only the info supplied by his customers is available, they may just be putting in the Manufacturers recommendations and a little bit more 'for luck'.

A bit of feedback from Abbey/Gary/Mario/Anyone on this would be interesting.


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## Steve W (Jul 30, 2002)

SORRY "Mr. Crofters".....

are you saying the manganese is _from_ the OB, or, from the
Optimax ? ?

and,

is this deposition only occuring because of the combined use of
both ?

ie. would it occur if only using _either_ ? ?

(is it a sort of 'over-addition' of additives ?)

"STILL-way-out-of-my-league"-FatS.

[BTW, STILL haven't got/used any Tol yet ! ! SO FAR (~6months)
have been using mostly Optimax and , OB if I couldn't get Opt']


----------



## Mycroft (Apr 13, 2002)

Iain or Mycroft 'll do.

From 'which' it is impossible to tell, it appears to happen when both are used in combination, Opt and OB.


----------



## Steve W (Jul 30, 2002)

Cheers Iain,

that's _probably_ OK then,
I can't afford to keep using BOTH at once 

(I drive like a woos most of the time anyway!)

Thanks anyway, FatS.


----------



## Peter (Jun 27, 2001)

Iain,

I think you've solved a longstanding mystery for me. When I took my stock turbos off my car to replace them, both wastegate chambers (?) were covered in what I took to be rust. This caused some head scratching as my car never has used any water so, in consultation with the experts, we concluded that as the car had been standing for a couple of weeks prior, this was the result of condensation and nothing to worry about. 

The main reason for me never really accepting this was why were the turbines also covered in rust being that they are ceramic? For the past year or so prior to this change, I religiously used Optimax and OB. I no longer use OB except on track days... I've still got them if you want a scaping?

Peter.


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## Blow Dog (Sep 4, 2001)

For what it's worth, I've stopped using Optimax. 
Had a tank full of it in the car for over 2 weeks a while ago, car really wasn't happy in it's running for a few days. Also notice excessive det with Optimax.
Texaco Super now with OB, runs much better.

Cem


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## Mycroft (Apr 13, 2002)

Peter.

No, been there, solved the mystery.

I'm pleased to have it further confirmed on here.


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## GTR-NUTTER (Jul 9, 2002)

sorry if i sound daft  but what should you use then   , and is optimax worth it


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## ctrlaltdelboy (Feb 22, 2003)

*Recipe?*

Hey Mycroft

do me a favour and tell me your 'preferred' recipe

I have 25L of toluene and 500ml of Isopropyl alcohol in my garage
how much iso should I mix with the tol and then how much of the resulting mix would you recommend to mix with super u/l or optimax?

cheers in anticipation - I'll let you know how it goes.

ps car is Honda NSX 3.0 VTEC normally aspirated, compression ratio = 10.5:1, low cam profile up to 5k rpm then switches to high cam until 8k rpm, I'm running a hi flow air intake with cold air induction, performance headers & exhaust and hi flow cats. around 300HP at the flywheel.


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## InsBro (Jul 29, 2002)

Some points they have answered, they will be glad to answer any questions!

From a website 
"Why is Optimax so variable?

Age, 'Optimax' has a 'tank life' it degrades quite rapidly as the super hot
benzene 'loses' it volitility after just 40days in the tank [the one in your
car or the one in the ground at you petrol station.

From this day, if you use it, then ask the attendent when the last delivery
of it was, if he can't answer then get the Manager, I've started doing this
lately and they are blissfully unaware of the time thing so answer with a
flourish of paperwork and a quizzical look. My rule is simple, look at the
docket, it says size of tank 10k ltrs, the discharged amount AT LEAST 90% is
needed to keep it at the 97/98 ron, the stuff in the tanker will be 98. this
started from the simple question posed me 'What RON is Optimax' the answer
is......enhanced 95ron...this is to avoid prosecution by the Customs and
Excise if they perform one of their checks.

Shell Say

"I will reiterate:

'Shell Optimax is 98 RON min, it is a completely new uniquely formulated fuel in which the high octane comes from refinery blending components not octane boosting additives. It also contains a top tier detergent additive which has the ability to clean away the deposits left behind in the airways of the engine by other fuels.

All Petrol, including Optimax, is manufactured to a specification which correlates to a storage stability of 2 years when stored under correct conditions. We do not, however, recommend that it is stored for a period of more than 6 months due to the seasonal variations of the fuel. The RON of Optimax would not decrease over the period of time that the fuel remains in the tank of the vehicle or the retail site, and is only likely to decrease by 0.5 RON max under very extreme conditions.'

The comments regarding benzene are irrelevant since benzene is not particularly volatile, and it is typically only present in quantities of 0.5%v/v or less in fact the specification for all grades of petrol is 1% max.

Optimax is 98 RON min, typically around 98.6. It is NOT an enhanced 95 RON fuel, it is a uniquely formulated fuel in which the increased octane comes from high octane refinery streams not an additive."

Another
"It also scrubs the tank, and this may well be what fooked Adis' cats, his
explanation of events fits the dirty tank scenario, apparently the smallest
tank on the forecourt is selected [this bit also explains why it is not
available nationally] It is cleaned and sealed with an inert gas awaiting
its new load, the inert gas does escape and if the gas is not present the
new surface scales into rust, the oxide is bad for the SH Benzene and makes
it behave oddly during burning, there is a precipitate (solid) formed and
this is what I think got Adis cat in trouble, the heating of the solid means
that it can perforate the matrix of the cat blowing a hole clean thu it in a
few hudred miles."

Shell 

"When a tank on a forecourt becomes available for Optimax it is drained and refilled in quick succession (if it is a diesel tank it may require testing for licensing purposes and this will be the only situation where nitrogen (or any gas) would be introduced). The tanks at our retail sites are manufactured from coated steel and therefore occurrence of rust is very unlikely. And again, the benzene issue becomes irrelevant on two counts."

Another

"Manganese is essential for Optimax to work (see my paper of Oct. 2000,
LSOC) I have found only traces of Toluene in Opt. for the most part it is
Xylene and Benzene."

Shell
"There is no manganese in Optimax. Manganese is often used in octane boosting additives, however Optimax is a uniquely formulated fuel where the increased octane comes from refinery streams alone. 

Again, the maximum benzene spec for all UK petrols is 1%, Optimax is typically 0.5% or less."

Another

"Optimax is high (very high) in Iso-parafins."


Shell

"Probably quite true - iso paraffins are generally high in octane."

Another

"Any 'metal' (if its compound is 'soft') will assist the valves and to some
extent the detonation. However some metals will cause the valves to rotate
to quickly (performance road cars valves rotate at around 1/2RPM, saloon
cars 1RPM) causing valve wear, this what caused all the trouble with Shells
last foray into the hi-performance fuels, that had to be withdrawn as the
claims against them were getting 'out of hand' I like what Optimax does, but
I am always aware that their last effort screwed cars over a 2year period, I
hate to feel like a long term test 'guinea-pig'. To some extent I feel that
way about all the OBs'."

Shell

"Optimax contains no metal compounds.

The fuel you remember was Formula Shell. Formula Shell contained a spark aider additive which was the cause of exhaust valve problems in a small minority of cars running on leaded petrol only. Shell Optimax is a completely different petrol formulation since it is an unleaded petrol and it does not contain the spark aider additive contained in Formula Shell. 
We have extensive engine test data showing that this unique high octane, clean burning petrol, with its market leading additive performance will enhance engine performance, improving responsiveness and giving superior acceleration. This has also been rigorously tested and benchmarked against other petrols currently available in the UK."

Helen Scholey
Technical Manager - Automotive Fuels
Shell U.K. Oil Products Limited
Rowlandsway House, Rowlandsway, Manchester M22 5SB, United Kingdom

I am just awaiting confirmation I can publish the email address then you can send your own questions.

Jeremy


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## Mycroft (Apr 13, 2002)

As this is the OB thread (primarily) I have replied in the 'Optimax' thread.

http://www.gtr.co.uk/forum/upload/showthread.php?s=&threadid=8636


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## ctrlaltdelboy (Feb 22, 2003)

for those of you that are intrigued by the octane boost offered through the use of toluene further reading is available here


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## milkytadpole (Feb 28, 2003)

Really intrigued by this thread, and the various inaccuracies within. Just have a quick question for Mycroft.

What's this institute you mention earlier in the thread?


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## Mycroft (Apr 13, 2002)

A minor discussion has started on Scooby-net on this subject... so far there is nothing on there is not already in here... but it may generate something new, I will transfer anything 'worthy' over here.

http://www.scoobynet.co.uk/bbs/thread.asp?threadid=180951&Page=3


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## Jason abz (Oct 3, 2002)

*hmmm.....*

An engine running optimax and booster with no deposits???
Mycroft, you said ........;-)!!!
So perhaps this is not just specific to optimax afterall??
Manganese or something wasn`t it mycroft?
This is really turning into a nightmare......i`m buying a steam engine!!
jas ;-)


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## Mycroft (Apr 13, 2002)

Jason I think you may not have understood John Banks posts.

John Banks is running Optimax and an OB and he has it.... in fact his motor seems to be coated in fine layer of it... 
---------------
I said that the deposit (and I quote) :- 

#As he talked me through each car after about 40 minutes or so (yep, a telephone conversation that could have bored the pants off a frigid nun locked in a fridge in the middle of a frozen lake in the Arctic circle) a pattern emerged, all these cars had run Optimax and Octane boosters which is exactly as I suspected the moment I saw that chrystal structure.

Now I must emphasise that NO DAMAGE had occurred, a few very cautious owners had paid for a couple of very expensive re-builds.

This is why this thread has been revived..because almost all the contributors and many of the readers of this thread I believe are just that cautious and enquiring.

Moral..It may look like rust, it may seem like you are heading for a big bill, but if you use Optimax with a high Manganese Octane Booster then don't have a brown trouser moment, check everything first, perhaps a little less OB?#
--------------------------------------
He also says he may have seen a similar thing but he ran both SUL with OBs'.


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## Mycroft (Apr 13, 2002)

Steve W asked:-

#are you saying the manganese is from the OB, or, from the
Optimax ? ?

and,

is this deposition only occuring because of the combined use of
both ?#

To which I answered:-

#From 'which' it is impossible to tell, it appears to happen when both are used in combination, Opt and OB.#

It is only a nightmare should you only partially read the thread... this is a thread that needs the reader to think...


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## Mycroft (Apr 13, 2002)

Some further reading of experiences regarding the OPTIMAX side of this thread... on page 2, I clarify further my thinking... should you require it.

http://www.scoobynet.co.uk/bbs/thread.asp?ThreadID=207812&Page=1

Should you not wish to trawl through further pages... I don't blame you!!!... my post below my 'contribution'...

###
Optimax cleans the cylinders and head... now once the deposits are gone the reason for your retardation goes as well so you can then return to SUL and it won't retard so quickly... so the real value of optimax is as a cleaner... run it every 5th-6th tank full and the car will be faster overall... you may need 2 or 3 tank fulls to clean it out in the first place but that is it.. in a nut shell, if you run rich and have dark Sparks normally then you should really attend to the fuelling but if you dont then Optimax is good at stopping a big build up of carbon...
###


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## EvoRob (Aug 30, 2003)

Mycroft! What do you reckon to this fuel combination and do you think that it could possibly cause internal detonation?

1 Portion of donner meat and chips, onions, tomatoes, topped with lashings of hot chilli sauce and Garlic Mayonaise and using a can of Tango as a Booster?  

Ive not tried it in my Evo yet but it deffo makes me do the quarter mile when im on foot a lot quicker as the chilli sauce gives you a lot of back pressure! 

P.S Could you do a lab test for me on that and the possible increases in internal activity that it would create!

Keep up the good work! V-Bird


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## Guest (Aug 30, 2003)

she-eet EvoBob, that aint on-topic.. someone will have to remove your post.

Heaven help anyone who tries to inject a little friggin' humour.


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## Steve W (Jul 30, 2002)

Mr. Myc'... or others ? ? 

Burtons (Gants Hill... Ford-ie place) sell Aldons Booster.

It is a 1Litre plazzie bottle and says "contains Xylene Isomers,
TOXIC " etc etc.

It stinks of Paint-ie smells (NOT Toluene, I KNOW what that smells
like - used it in old job)

Q: Is THIS liable to be 'more' Xylene-ie/Toluene-ie in nature than
the likes of Millers etc.

ie. _better_ at actually increasing OCTANE rather than _allowing_ 
the Timing to be advanced ? ? ?

(I'm having trouble finding a local Toluene supply and trying to
find some CR*P-in-a-Bottle that'll _nearly_ do the job ! ! )

FatS.


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## Mycroft (Apr 13, 2002)

Avoiding Evorobs' diversion as best I can, this thread has to be 'revived' again... due to the introduction of BP 'Ultimate'.

Steve W... you need at least 7% by volume to make any tangible difference. little bottles = little difference.

There has been some discussion on other forums about this 'new' fuel, sadly almost all has been 'wrong headed' or has entirley missed the point.

In an effort to do what all the refinery companies shy away from I will try to explain how things are not always what they seem.

As usual, you need some history for this to make some sense.

In this Country we adopted a system of 'Star' [*] ratings for fuels after it was found that one 'Super' grade of fuel was not as 'super' as it maker would have had you believe, so the introduction of Star ratings came about 2 3 4 and even 5* fuels could be found on the forecourts of the UK.

After a short while even this was 'abused' and further more accurate measures were needed, at this time we faced a choice, we could go for either the 'expensive to check' MON or because of the ESSO companies '100oct 5*' fuel logos on their pumps the alternative bigger numbered RON system, at the time RON was a better guide for the more uniform fuel found in the UK [very small temperature variance through the year] So we then adopted the RON system and the numbers we love to 'bandie' about like '95' '97' etc were 'enshrined' here.

I could if you wish explain the difference between RON and MON in some detail but ditchwater is less dull so I won't. 

So all was fine, the fuel until very recently fitted very nicely within the accepted formula from one system to another... you see until now 100 RON always was 91.5 MON and vice versa...

This was due to the base and top out chemicals used to form the basis of the 'formula'

Then they started making some rather neat coc-ktails that really started to blow holes in this, our chosen rating system, you see the real figure that matters is not RON... the really important rating is MON... you could say that our system of rating has been made somewhat redundant...

So although we may rate a fuel here as 97oct [RON] which would have been 89 MON in reality it will still only attain 97 RON but might show 91.5 MON when tested to that 'standard' now by the old conversion factor to get 91.5 MON you needed 100 oct [RON] fuel.

I hope that clears this little matter up.

Questions?

[Copyright Dr. Iain Wiltshire, 12/10/2003 Not to be copied/transcribed without permission of Author]


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## Howsie (Feb 25, 2002)

Mycroft, I don't suppose the oil compaines list MON ratings anywhere because of this then? Are they listed anywhere on an independent reasearch site or have you done you own?

Cheers,
Howsie


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## Mycroft (Apr 13, 2002)

Now you come to mention it, but I do have that info and I will tomorrow endeavour to retrieve it from the system and on my return from my duties post them on here.


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## Gez (Jan 8, 2003)

Soo the real question we should be asking is the MON rating of BP ultimate. Anyone know the answer to that question????


Cheers

Gerry


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## Mycroft (Apr 13, 2002)

Shell Optimax.

RON 98.3 [tested independently]

MON 89.2 [tested independently]

Using the 'old formula' one would expect 98.3 RON to be around 90.5 MON, so if you do the sum 'backwards' for 89.2 MON the figure of 97 RON is achieved.

BP Ultimate.

RON 97.2 [tested independently]

MON 90.3 [tested independently]

Using the 'old formula' one would expect 97.2 RON to be around 89.4 MON, so if you do the sum 'backwards' for 90.3 MON the figure of 99 RON is achieved.

The divergence you see in the above is set to worsen over the next few years as others try to get in on the act.

[Copyright Dr. Iain Wiltshire, 13/10/2003 Not to be copied/transcribed without permission of Author]


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## AndyF_RSX (Nov 26, 2002)

Iain,
Where did you get those MON figures from because when I asked BP about the MON rating for 'Ultimate' they told me it was 97RON and 86MON so I'm interested as to where you got your figures.

Cheers

Andy


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## Howsie (Feb 25, 2002)

Interesting. Cheers Iain!


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## Mycroft (Apr 13, 2002)

Test results from the refinery!

I think that they sent may have been a typing error, they should have sent [so as to not confuse the masses] 89 MON which on the original formula equals 97 RON... it should say something like '... at least 89 MON' that is what I received from them!


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## chunky (Oct 14, 2003)

So am I right in thinking that had either of these fuels been marketed in the US they would be sold with a 94 octane sticker on the pump? Or more specifically 93.75 octane?


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## Big Mark (Nov 27, 2002)

> So am I right in thinking that had either of these fuels been marketed in the US they would be sold with a 94 octane sticker on the pump? Or more specifically 93.75 octane?


That would seem to be the case..... (RON+MON)/2.


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## AndyF_RSX (Nov 26, 2002)

Iain,
Looking at the BP australia website it gives the following RON and MON's

Regular Unleaded 91 and 82
Premium Unleaded 95 and 82
BP Ultimate 98 and 85

I can only assume that this 'BP Ultimate' is different to the one that we are getting. Is that correct?

Andy


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## AJFleming (Feb 25, 2003)

Why all this nonsense petrol? Why on earth dont we get the same fuel as Japan?!?!?


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## Gez (Jan 8, 2003)

TAX is one word  
Best crude is British but unfortunatley we dont get it (surprise surprise).
We just get the cheap crap on the market so the gornement and Petro-chem companies make silly amounts of profit. 

Many thanks

Gerry


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## AndyF_RSX (Nov 26, 2002)

Just to add a bit more info I've received....

All SUL in the UK has to have a minimum MON of 86 and this is what BP are claiming for 'Ultimate'

Shell also claim a minimum MON of 86 for Optimax however I've had a response from Shell saying that a MON figure of around 87.5 is a 'realistic' value of the MON rating.

Any comments Iain?

Andy


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## Mycroft (Apr 13, 2002)

Read this...

http://www.asa.org.uk/adjudications...how_advertisers&dates_of_adjudications_id=all

The truth will 'out' eventually.


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## JasonO (Jun 29, 2001)

Mmmm, Intresting


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## dan0h (Jul 26, 2002)

Didnt doubt you for a minute Mycroft ... I dont rate Optimax either, and we certainly dont map on it at Abbey's...


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## Daz (Aug 14, 2001)

So you want me to fill-up on BP Ultimate before I bring my car up next weekend then Dan ?


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## IanH (Nov 23, 2002)

Ran mine on Optimax for almost a year with no problems (at 1.2bar for 3 months) or knock, had to use BP Ultimate once and was forced to turn the boost to 0.8 to avoid knock.

Engine really didn't like it!


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## Daz (Aug 14, 2001)

I've only used BP Ultimate twice ... and the car felt a bit hesitant on it.

Generally I use optimax.


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## Smithicus (Mar 25, 2004)

What is this CVL stuff people were talking about on the first page on the thread?


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## Samuel Cross (Aug 2, 2002)

www.millersoils.co.uk

Have a look on here Smithicus.


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## Smithicus (Mar 25, 2004)

Where can i get some Good octane boost for my skyline, as im in the USA, and we only have 94 oc. Anyone know of a place in America, or a company that will ship here.


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## Fadhel (Nov 23, 2003)

*An amazing thread*

Had a question as well if Mycroft is still reading this..

Is this mix recommended for low octane gasoline as well (Such as 90 RON)? Or will it be just too much risk?

Thanks


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## Saabman (Aug 5, 2004)

Some more questions for Mycroft,

What is the advantage of toluene over xylene? Doesn't xylene have a slightly higher octane rating? Is there some other drawback?

The small amount of isopropanol added to your toluene mix is mentioned to prevent flareing, is this during combustion, or is at a safety precaution during handling?

Just read all 24 pages and am fascinated to try this..............


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## Yunis A (Jul 25, 2004)

what about cellulose thinners? containg xylene/toleune?


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## Mycroft (Apr 13, 2002)

Fadhel, my apologies for the very late reply...

The answer to your question is that Toluene/Xylene can be mixed with any 'gasoline' to increase the Octane rating and so long as you take a 'considered approach there should be no detrimental effects.

Saabman, there is no advantage of Toluene over Xylene, they are almost equals, Xylene is slightly superior, but the margin is small.

The Iso-alc is for during combustion.

Yunis, yes I know of a few people who have done this, but i have not tried it myself, all seem to be perfectly happy to get their Xylene/Toluene that way.


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## Neil_H (Mar 30, 2004)

Smithicus said:


> Where can i get some Good octane boost for my skyline, as im in the USA, and we only have 94 oc. Anyone know of a place in America, or a company that will ship here.



Don't the US use the MON rating system (which is a lower number than the RON equivalent we have)?


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## ctrlaltdelboy (Feb 22, 2003)

Neil_H said:


> Don't the US use the MON rating system (which is a lower number than the RON equivalent we have)?


Neil, in the US they use 'octane' ratings which are (RON+MON)/2 so using the figures posted by Iain a year ago on P23 of this thread, and shown below


Mycroft said:


> BP Ultimate.
> RON 97.2 [tested independently]
> MON 90.3 [tested independently]


we can deduce that the US pump rating for this fuel would be 93.75 so in answer to Smithicus's question


Smithicus said:


> Where can i get some Good octane boost for my skyline, as im in the USA, and we only have 94 oc. Anyone know of a place in America, or a company that will ship here.


the answer is that your fuel is as good as the best we have over here, it's just labelled differently.

Hope this helps


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## ctrlaltdelboy (Feb 22, 2003)

Smithicus said:


> What is this CVL stuff people were talking about on the first page on the thread?


this is useful too http://www.millersoils.net/pdf_downloads/octane_fuel_test_results.pdf


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## skymania (May 28, 2004)

Blumming heck this thread should win the 'Longest Thread Award'


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## kenan (Apr 29, 2003)

Mycroft, if I can't get to a Shell garage for me Optimax and end up having to use 97 is there any point using any of the OB's ???

I have always run my car on optimax and was advised that an OB would take the 97 to a similar level of fuel


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## ctrlaltdelboy (Feb 22, 2003)

woo-hoo!!

the OB thread lives on, 3 yrs & 3 months and still going strong


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## Froos (Oct 24, 2006)

Ok guys, where can you comfortably buy Toluene/Xylene, since its also used for makin syntetic drugs.....dont feel like getting busted buy the man next time i pull into the pitlane


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## SiKBoY (May 15, 2006)

Whoa thread revival !! 

So who is gona go back through this thread and re calculate everything now we have V-Power and Tesco 99..


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