# Inside the Garage Bomber



## ATCO (Feb 2, 2003)

You know how people come on here saying they can buy a GTR from Japan for a few thousand Yen and a bag of Haribo's, so why pay £8K+ for a car here? And the old lags(!) bang on about buying a "UK" car so you know what you get, as averse to buying from Japan with the risks that entails. Well herewith is the lesson, but it isn't all bad news.

Well I've bought from Japan directly twice. In both instances it wasn't quite what it said on the box. First time it was close, with a few pleasent surprises like TEIN suspension which had not been mentioned and not so pleasent, like repaired panels and paintwork that needed a full re-spray, also not mentioned. In the end I suppose it worked out about the same price as "local" when everything was put in order.

When it came to buying the Garage Bomber, considerable caution was applied and lots of questions asked given the nature of the beasty. Let me be absolutely clear here, I was dealing with people I knew who answered my questions to the best of their knowledge, I am not aware anyone deliberately "lied" they just reported what they had themselves been told - you should remember the cars frequently have very limited history, sometimes none at all, and may have passed through several sets of hands.

Parts which had been on once may still, or not, be on. It is very easy to get your fingers burnt. Big time.

Here is the original "spec" of the Garage Bomber:

Hi David 

Here is a spec list that he has for the car
He said that there is much more to this car but this is just the main parts that he can remember.

Engine 2.7 capacity - _yup, got that_

Tomei full counter crankshaft 12000 revs - _think we got that, in process of being checked_

Stage 2 HKS pistons - _definitely got that_

Apex rods - _think we got that_

Tomei oil pump and oil pan - - _Not sure if its Tomei but it is definitely a good one_

Hks race type crank balancer and pulley kit - _yup, got that_

Head-- Ported - _sort of got that, incomplete port and poor surface finish. But fixable._

280 intake cam--290 exhaust cam - _no didn't get that, both are HKS 280 degree and 10.5(?)mm. Unfortunately the intake cam is now scrap because there was insufficient clearance on the bucket to head for it too fully open properly. Its not short by much, so cam can turn, but the cam has worn a hole in the bucket and broke off the valve head as well as putting a flat on the lobe. Same symptoms showing on cylinder 2._

valve springs,valves - _yup, got those. Only trouble is was that half the springs are upside down. That's a novel approach, why would someone do that...... We did get beryllium seats though and bronze guides._

1.2 drag hks gasket - _no, didn't get that. It's actually an HKS 1.6mm gasket which works wonders for the compression. Peak boost was set to 2bar, so why would you run such a thick gasket?_

Turbine-- HKS GT3037 with dual external wastages - _they are actually GT3037S's_

Greddy intake plenum- _yup, got that_

braided fuel lines- _yup, got those but had to replace them after two burst_

2 greddy fuel rails - _yup, got those_

12 injectors (1000cc+440cc) - _nope, turned out they were 660 primaries (which where not working very well) and 375 secondaries. It now runs HKS 1000cc+original 375. In truth twin 700's would be a better combination._

2 HKS large fuel regulators - _yup, got those_

HKS AFC - _yup, got that_

big flow meters - _yup, got those but now long gone_

catch tank - _yup, got that_

Intake/ Fuel -- 49mm throttle bodies - _nope, got standard GTR TB's. Have you SEEN the price of the bigger throttle bodies!  _

4 fuel pumps - _yup, got that_ 

trust 6 speed gearbox - _yup, got that. It was broken and needed to be repaired, again and again and again....... Now replaced with a sequential - everyone should have one!_

4 plate OS clutch - _nope, it was an HKS triple_

Intercooler-- 4 core - _yup, got that_

Hks front drag axles - - _nope, standard front and rear_

Driveline: Cusco front and rear limited slip - _yup, got that_

4 wheel steering delete kit,HKS 4 wheel torque controller with ETC drag adapter - _didn't get ETC DA it was taken off and didn't know the controller had been modified which is how we got it stuck in RWD mode........._

pro start and line lock. .- _yup, got those_

Body--Carbon wing - _nope, possibly stolen out of car during shipment....._

carbon bonnet - _yup, got that. It flew up on top speed run at TOTB and broke the windscreen........._

radiator shroud - _yup, got that along with standard rad! Now a PRO Alloy rad lives there._

electric fan - _yup, got that_

Top secret body kit - _yup, got that_

Jun rear bumper - _yup, got that_

full dual exhaust system - _yup, got that. Its actually a full race system. Pity the centre section pipes are too small in diameter_

carbon trunk - _yup, got that_

Suspension--HKS drag with drag arms and bushings - _certainly HKS Drag suspenders, not sure on rest_

front and rear fibre sway bars. - _maybe!_

Electronics: Greedy (profic boost control and gauges). - _yup, got that but now HKS V-PRO and guages_

Auto meter RPM gauge with memory and play back.- _yup, got that_

Seats—stock available but now 2 Reccaro buckets (new).- _got stock not Recaro  _

std brembo R33 brakes - _yup, got those unfortunately_

New 18 volk T 37 wheels with 265 35 tyres - _yup, got those, absolute b******* to keep clean._

GTR Zenon lights - _yup, got that_

So what other things do we now know?

Well the pistons are perfect, no det marks at all. Just slight marking on the combustion chamber in the head.

Bores are perfect. Block is an N1.

Some of the engine work is brilliant, some isn't. Looking at the head gasket it looks like one of the more recent HKS ones. As the head has never been off while I've had the car it suggests it was taken off not long before it left Japan, perhaps even that the head was swapped which might explain some of the really weird things about it.

The biggest mystery? 

Well, consider with the 1.6mm gasket, the cam/valve and valve spring arrangement etc. etc. how was Gary Passingham able to squeeze 845BHP at the wheels at 8250RPM out of the engine? I know he did because I was there at the time! Also why was the old girl so willing to rev to 10k+? Speaks volumes about the RB26, the new V has a lot to live up to.

And the next question is, with JUN Step 2R 11.35mm lift 288/293 cams, 1.2mm gasket and lightweight valves, will I need a parachute? 

In summary, do I regret buying the Garage Bomber? Absolutely not, I had assumed all would not be as stated because that is the way it is. However, let these be words of caution to anyone looking at those "bargain price" deals and thinking "how much of a risk can it be?".

DaveG


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## WIT BLITZ (Apr 1, 2007)

COOL! A new project to follow!


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## Dave_R1001 (Nov 24, 2002)

Dave was the Bomber the car that Chris Archer nearly bought? We used to rent a house together and I seem to remember him mentioning that the car went to someone else instead?


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## Pimpernel (Dec 5, 2003)

The Bomber was almost Chris's car. I was ahead of him in the queue so he got the "sister car" with the single turbo when I said "yes" to buy.

Update on the above list.

Tomei full counter crank - no, its standard HKS.

Apex Rods - no, they are HKS.

It basically had a 2.7L HKS kit in there............ 

DaveG


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## blue34 (Jul 28, 2005)

So i't most definately in pieces then... and an HKS stoker kit ain't too bad after all... sounds like the re-build is going to be mostly head work then... hopefully it'll be up and running in no time...


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## ATCO (Feb 2, 2003)

It all depends Malcolm.

Yes the HKS Kit isn't "junk", however it was supposed to be a full counterbalanced Tomei for 12,000RPM, which the HKS kit isn't!

Not sure how Apex rods compare to HKS, probably not much in it.

The cams don't compare, especially with 10.2mm lift, as it impacts on performance, as does the unfinished porting job.

The 1.6mm gasket was another performance weakener and might explain why I've always felt that "torque" was missing. That's 8.3 compression instead of 8.7, with the benefit you get throughout the rev range. Accepting that the lower compression was also kinder to the engine........... It could have been worse, a 2mm one!

It's one of those feelings where having originally expected a few "shortfalls", the list has steadily grown, especially in a few critical areas. Makes you wonder if it is the engine Aki originally put in it.

Also interestingly, Gary is reporting that the bottom end is looking "black" and ashen indicating lubrication property breakdown. He says it isn't short of oil, just that it hasn't maintained the "film" between parts with indications the oil has actually failed.

I've always used Silkolene Pro, regularly changed, however the implication is it wasn't up to the task and temperature has killed it. Given it normally max's around 100-110, with most I've ever seen being at Brunters with 115, looks like it will be redline in future...........

It will not be ready for Rotorstock, awaiting the JUN cams, plus a few valves and another session on the dyno. So you can borrow the tyres again Malcolm!  

DaveG


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## rasonline (Mar 24, 2005)

Tomei crankshaft is full counterbalanced. Read more about it here
TOMEI WEB Catalog


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## paul cawson (Jul 3, 2003)

ATCO said:


> The 1.6mm gasket was another performance weakener and might explain why I've always felt that "torque" was missing. That's 8.3 compression instead of 8.7, with the benefit you get throughout the rev range. Accepting that the lower compression was also kinder to the engine........... It could have been worse, a 2mm one!




It would be worth checking that the head or block has not being skimmed.
The grade marks should be visible on the block surface the head will need to be measured


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## Pimpernel (Dec 5, 2003)

Correction to above post.

It definitely isn't a HKS crank, it could well be a Tomei after all. It definitely is a good one, just hope it isn't bent!

Rods are not manufacturer marked, so they may be Apex too, don't look like HKS.

Pistons are definitely HKS!

The crank shells are heavily scored, slight marking on crank which should polish out.

Head being pressure tested and inspected. Not sure if its been skimmed.

Checking on valve springs, they were all upside down. Possible they are HKS Step Pro. Standard Nissan valves.


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## blue34 (Jul 28, 2005)

*how about an update Dave!*

All quiet on the ATCO front lately - know you been busy at work but how's the engine re-build going Dave?


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## ATCO (Feb 2, 2003)

Oi, you looking to cause mischief!

As you know the Team re-installed the rebuilt engine on the Saturday afternoon before the Jap Show Finale on the Sunday...........

I "ran in" the rebuild on the 150mile trip up there. Initial impression was that the car semed to have more low down grunt coming in slightly earlier than before and wasn't short of upper end power. This was against the change from 1.6mm gasket to 1.2mm, so increased compression was helping. The flip side was of course longer duration, higher lift cams had also gone in, however this did not seem to be proving too detrimental to low/mid rev running.

There hadn't been time to re-map the car before leaving so I was keeping one eye on the AFR on the way up and noting that it was typically running about 2 points or more higher (weaker). This was 1.6bar on SUL. 

At the Jap Show, a slight delay (cough) in the arrival of my 17" tyres and race fuel (they were in the truck) meant the first two runs were done on rock hard 18" Dunlops, 1.6bar and SUL, resulting in high 11's. By the final run I had 17" wheels, 2bar and safe fuel. Result was a 10.3 quarter. I also reported the worryingly high AFR numbers but couldn't be precise as I am a bit busy going up the quarter so couldn't focus on the AFR readings.

"Next time you cross the line keep your foot down and read the value" were the subsequently infamous words.

As I previously reported I fluffed the start in the first knockout so lost the run to the line, but as instruction I kept my foot down across the line (in 4th) and focused on the AFR. 15.29 it said. Can't be I thought and focused hard. Yes it read 15.29. Triple  At which point the engine went bang throwing No1 rod straight through the block. O bother I said............. :flame: 

150miles and 4 runs up the Pod, one rebuilt engine written off.

Analysis was that the engine was probably doing at least 11,000RPM (155+ mph at the time, limiter was set to 20,000) and on strip down it was clear that No1 big end had been starved of oil likely due to the high flow pump emptying the Trust sump faster than it was draining back. The Big end shells welded themselves to the Crank, this snapped the rod, the end of which exited out the block. Wasn't a build failure, so no warranty claim!  It was simply over revved. Gary has muttered something about rev happy Clients and setting the limiter to 9000 (but he's a wimp  ). 

Luckily(!) I hadn't got the trick Veilside block on but the original N1.

The result is a new JUN billet crank, rods, pistons, Veilside block, oil pump, bearings etc. etc. which are being mated to the old head, which is the only part we could recover. 

The 1000+375 injectors will also be swapped for twin 700's and the Kakimoto exhaust will be replaced by a custom item from MIJ Performance.

Following which the merry-go-round can start all over again. 

Don't you just love Skyline ownership, where else could you pay for the priviledge of being driven insane?

DaveG


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## Nicolas Kiesa (Dec 13, 2003)

Nice thread and write up,
Very exciting to read and I can almost taste your entusiasm in the quest for horsepower and reliability.

In 2005 I as well blew a lot of Sh1t during the AEM ecu introduction dramas and I never gave up, on engine 3# I souced it and has run great ever since.

Good luck getting there 
Kismo out


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## Madden (Nov 14, 2004)

Good write up mate. I enjoyed the the read.

What the veilside block then?


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## Smokey 1 (Nov 1, 2005)

ATCO said:


> .
> 
> Analysis was that the engine was probably doing at least 11,000RPM (155+ mph at the time, limiter was set to 20,000)
> 
> DaveG



Jezzzzz Dave would love to see the dyno graph for that, dont know anyone who's redline is that high, you the man  


Smokey :smokin:


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## blue34 (Jul 28, 2005)

I only wondered if if it was going back together yet... thinking of changing the head studs for bolts on mine before we give it any more beans... see you soon!


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## chris singleton (Jul 20, 2005)

Why was the rev limit set to 20k


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## m6beg (Apr 21, 2003)

Because its a special engine that revs to 20.000 rpm and makes 6.000.000. bhp lol:chuckle: :chuckle: :chuckle: :chuckle: 


Mick


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## tim at svs (Jun 29, 2001)

*Nice write up Dave*

Especially like the fact that you remain enthusiastic despite all the set-backs !
Tech list is impressive and detailed, however could you clarify, what sort of 'sequential gearbox' are you running ? Whats it like, any good ?
best wishes
Tim


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## ATCO (Feb 2, 2003)

m6beg said:


> Because its a special engine that revs to 20.000 rpm and makes 6.000.000. bhp lol:chuckle: :chuckle: :chuckle: :chuckle:
> 
> Mick


I wish Mick! If it did I could have easily sustained 250 for a mile in both directions!  

Nicolas, you know what is like, sort out the problem and move on (and up) to the next one!

Madden, its an early R32 block that came off an official Veilside car. It "looks" standard but is heavier and made from something other than the standard material.

JohnB, we've never rev'd it much over 9 on the dyno as it isn't kind to the engine and Gary has too much of a sense of self preservation in his body and the engine.

Chris, if you take off the rev limiter on the V-Pro it defaults to a 20k value as it has to put a number of some sort in there. Of course I don't think any RB26would rev to 20k, although Mario I think goes to 15k, but that's Mario of course! You may have noticed that on the strip I never hit the limiter, I changed gear when the shift light came on at 10k. Gary has always wanted to set it to 9 but I made him take it off...... :chairshot I'm now prepared to compromise and have the limiter on, 10.4 has the feel of a good number..........

Tim, it was designed for a Viper!  Apart from the lousy reverse, the baulk between 3rd and 4th and the awful constant whining its OK, the much faster gearchange and ratios over standard make it tolerable. Needs more development though.

DaveG


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## chris singleton (Jul 20, 2005)

Could the failure have been caused by excessive revs?

Is it still making peak power past 9.5k?

Not having a dig, just genuinly interested


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## ATCO (Feb 2, 2003)

Chris,

Failure caused by high flow oil pump (mechanical, so flowrate -rev level correlation) emptying Trust sump faster than it was draining back, might have also been compounded by hard acceleration which "drives" oil toward rear, even though it is baffled. 

The failure was caused by oil shortage to No 1 big end shell, which welded itself and the bottom end of the rod to the crank. The crank force snapped the rod and put it through the block in a very similar way to how John Bradshaw's engine went. His was fixed by going dry sump, which isn't really practical for my road use.

Given what we saw pre-rebuild inside the engine, slight signs of oil failure/breakdown on No 1, it looks like I've run "on the edge" a number of times before but not quite gone over. This time I did.

The implications are that the JUN/HKS/Renix pumps can outflow a high capacity (slightly overfilled) baffled sump at somewhere near 11,000RPM under hard acceleration (also I presume under high corner speed conditions too). Logically something like an accusump would be a wise investment for high rev applications for peace of mind, or keep the revs down a bit.

For information, the rest of the engine was perfectly sound, bores OK, pistons fine, billet crank on 2 thru 6 perfect, the high revs had had no detrimental effects at all. Makes you wonder how high the revs really could go.

Pre-previous rebuild, so lower compression and diddly squit cams (272/10.2mm lift), peak torque came in about 6250 and was pretty near flat all the way through to just over 9000. Way the car ran it was still holding up at 10k, we estimate making about 500ftLbs. 

DaveG


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## Cord (Aug 21, 2002)

I wouldn't be so quick to state that the main problem is the pump is emptying the sump. When the pump is doing 11,000rpm yes it is consuming a lot of oil, but not all this oil is going into the engine, a great deal will be getting dumped through the PR valve, via the drain straight back into the front of the sump. I think it far more likely that enough oil is not returning from the rest of the engine into the are within the sump that it is needed.

Just wondering are there any signs of damage within the oil pump, 11,000rpm is way past what it is designed to do. I would be very suprised if it is capable of drawing enough oil through the relatively small feed paasageways to run without some form of cavitation occuring?


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## m6beg (Apr 21, 2003)

ATCO said:


> JohnB, we've never rev'd it much over 9 on the dyno as it isn't kind to the engine and Gary has too much of a sense of self preservation in his body and the engine.
> DaveG


Just a thing that is wondering me if you only rev the car to 9.000 rpm on the dyno. Why do you rev it to 10.400- 11.000 rpm on the strip ? surely the car will be mapped to 9.000 rpm. So your reving the car to what ever without the remaining rev's being unmapped!

That is very very silly.

Tweenirob wanted to do a test on my car to see when the peek power dropped off. So limiter was set to 10.000 rpm and the car was still making power never dropped off at all. But stopped reving it that hard as it causes problems. If you need to rev her that hard i would suggest you change your set up as you are not happy with the power. Remember high rev's will cause problems! 
Get some bigger turbos mate and rev it to 9.200 you will do a 9. If someone else drives it lol (only kidding) :chuckle: :chuckle: 

Dave you have a great car there just need a Perfect Touch me recon's.



Mick


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## ATCO (Feb 2, 2003)

Cord, damn good question, Rod isn't paying you enough!  

As we are down into the weeds and where the "Tuner tricks" lie, i.e. those who really know how it works.....

No, we don't think its the pressure relief valve cutting in, the oil pressure log on the HKS guage does not show "excessive", with peaks around 6Bar and so we don't think its a consequence of triggered "short circuiting". Remember, the GTaRT crew have knowledge/experience of what has been learned with John Bradshaws engine too.

Of course it is all "conjecture" put think fully about the overall process, its not about 'backpressure' and therefore rising pressure, its more about oil collecting toward the back end of the engine from top to bottom and being held back from being recycled - we are thinking about baffling the rocker covers too (Rod knows what we mean, don't want to give too many trade secrets away). There is logic in your hypothesis Cord and it is worthy of not entirely being discounted, however on basis of all the facts observed the primary conclusion is the pump out pumped the sump! 

Mick - are you on commission from Tweenie!  

The map is mapped to 11000RPM. I specified this to Gary at the outset as this has implications on map granularity (finite number of cells available in V-Pro, and yes its more than any other ECU). Yes its true that for the "perfect touch" each map cell should be tried, tested and validated, however given the data available we extrapolated the map into the higher rev ranges. The final validation came from readings on the sensors from real use on the tarmac. We took a known risk with the engine mods at Jap Show Finale, but it wasn't the cause of the failure.

Don't know what your problems have been, but I've been reving the Garage Bomber to 10,000 regularly since 2004 without any problems. (Gary and Aki think I'm crazy, but what do they know, they are only experts! :chuckle: ). She sings to me beautifully! (You know what I mean Mick). 

We also now know the problems at 11000 revs so it is ever so tempting to install the fixes and push the bar even higher, other than Gary insists he does not want to rebuild the engine again (he's on a guilt trip because he is the one who told me to keep my foot down). Personally, I've no problem with the revs, I lived with 13,500 to 15,000 before without issue (but not with a RB26 I add) and the sound is addictive, let alone the speed.

Anyway, I like what I've got and despite giving you about 2-300Kg benefit I'm not far behind you Mick!  (Queue personal diet opportunity). And we both love what we are doing, we just need more to come and join the Club don't we? :thumbsup: 

For those who are remotely interested, check out the latest issue of Jap Performance magazine, yes that ugly bar steward is me! Even Zoe couldn't create a Brad Pitt impersonation for the camera! 

Onward and upward, to infinity and beyond, slip streaming the JUN Lemon before selecting top gear.................    

DaveG


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## tyndago (Oct 24, 2002)

Your insane.. 11,000 rpms. Thats motorcycle territory there. Well not the new ones, but old motorcycles.

I really dont like the RB rod bearings, or oiling enough to rev the engine that high. I have done in plenty of #1 and #2 rod bearings.

I have uncovered the oil pickup too many times on a road course. Aki was with us at Laguna Seca when we tacked two engines in the R34 World Challenge car.

If it were to be reved that high I would have to go to a dry sump. No other way to ensure the engine has oil.


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## ATCO (Feb 2, 2003)

OK, I'm prepared to re-phrase my comment.

Gary, Aki AND Sean :bowdown1: think I'm crazy!

In my defence (defense for Sean) I have admitted above that I'm prepared to accept the limiter set to 10,400.

Does that make me only half crazy Sean?

DaveG


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## tyndago (Oct 24, 2002)

ATCO said:


> Gary, Aki AND Sean :bowdown1: think I'm crazy!
> In my defence (defense for Sean) I have admitted above that I'm prepared to accept the limiter set to 10,400.


Ha ha. Id rather do big boost than big revs. The other day Wakita did 39 psi on Johns car. Thats the way to true enlightenment. 42 psi + . How much boost ? 3.0 bar. 

Too many people stop at 30 psi . Just because your gage stops there , doesnt mean you have to give up at 30.


Again though. The oiling system, and oil pump drive on an RB leaves a lot to be desired. I have looked at a JUN pump that I reved to 9500 a few times, and the cavitation marks on it are scary. Reving that high, you just can't pickup enough oil to feed the oil pump. The cavitation will kill the engine. I though a little about opening up the oil feed - suction side a bit , but I'd rather keep the r's down and run 45 psi with a little shot of nitrous to get it up there.


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## ATCO (Feb 2, 2003)

Know what you mean Sean. However the 3037S Turbo's would be off the island at 3Bar and Gary quotes me "2bar OK, 2.25Bar the bang is coming, 2.5Bar the big bang is here" and Mr Tanaka says if 2bar isn't enough you need bigger turbo's (Hi Mick!).

HOWEVER, I drive this car on the road, regularly, between tuner shop visits (its on a time share) and 3240 or bigger is not actually that road friendly from a power point of view. I already drive generally "off boost" below 4000because if I allow it to spool up the acceleration (and speed) is manic and licence shredding territory.

Not easy circles to square!

Aki did say 9000 OK forever, 9500 annual rebuild. He went quiet when I said I rev to 10.......

Plus of course, nitrous is cheating, shame on you!

DaveG


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## blue34 (Jul 28, 2005)

If the torque holds up, i.e. the engine can continue to get enough fuel and air in and exhaust out - which it can - then the faster it spins the more power it will produce.... no need for higher boost.... and an extra 1000rpm means a big increase in power output and higher speed in any given gear. That's I think why our Dave likes his revs and why he's building the engine with the best components to withstand the revs.


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## roadie (Feb 6, 2006)

Wow, keep it up guys. This is the best thread in months. It's like shaved ****** when you were aiming for second base !!!!!!


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## tyndago (Oct 24, 2002)

ATCO said:


> "2bar OK, 2.25Bar the bang is coming, 2.5Bar the big bang is here" and Mr Tanaka says if 2bar isn't enough you need bigger turbo's (Hi Mick!). and 3240 or bigger is not actually that road friendly from a power point of view.
> Aki did say 9000 OK forever, 9500 annual rebuild. He went quiet when I said I rev to 10.......Plus of course, nitrous is cheating, shame on you!


The last time I talked to Aki I mentioned your signature with the 10k quote in it. 



Nitrous - cheating ? Wheres it cheating ? Its just nitrogen and air. Just another way to put some more air into the combustion chamber. Sure wakes big turbos up quick. 

Anyway - 2.25 bar .. have to look at a compressor map for that turbo. C16 fixes everything. I hear Q16 is even better though.

It looks like its still good up at 2.5 - 2.75.


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## tyndago (Oct 24, 2002)




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## ATCO (Feb 2, 2003)

Sean, that's a 3076 Map you've put up, not a 3037S. They are different. Even with the 82mm the 37 does not get up to the 3076.

I was tempted to "upgrade" to 3076 or even the 308X series, however HKS advised against it.

You are right though, you can push it to 2.5, 2.75 I'm not so sure about. I use Sunnoco 119, not C16 and NOS is for when you've run out of ideas to make it go better!  

DaveG


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## tyndago (Oct 24, 2002)

ATCO said:


> Sean, that's a 3076 Map you've put up, not a 3037S. They are different. Even with the 82mm the 37 does not get up to the 3076.


I beg to differ. According to HKS information...

tyndago - GT-R Turbos

GT3037 420 48	52.8	76.2	70	50	0.60	84	60	55	
440	52	55	76.2	70	50	0.60	0.73
470	56	57	76.2	70	50	0.60	0.87
GT3037S	450 52	55	76.2	100	50	0.60	1.01
480	56	57	76.2	100	50	0.60	1.1

2835 is 71.1 mm on the big side of the exducer. All the 3037s are 76 mm on the big side. The 3240-3540 are 82 mm.

The 3037S are 55 mm and 57 mm on the inlet side. The compressor map above is for the 57 mm inlet. The 55 is a little smaller and according to HKS worth about 30 hp less per turbo.

Nitrous is great fun stuff. Just more air. Just more cold air is all it is. The only people that say its cheating , should be the same people that say a turbo or a supercharger is cheating.

I tried Sunoco - I still believe in C16. 137 mph in the quarter on a stock RB26.


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## ATCO (Feb 2, 2003)

Hi Sean, don't dispute your sizing figures at all.

I haven't overlayed your map, but checking by eye the 3076 seemed to deliver better.

GT37









and the GT30;










Haven't tried C16. The car was mapped on Sunoco and as you know every 'blend' is different so stay with the same one as a precaution. Might be interesting to do a dyno run with C16 in just to see what happens.

DaveG


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## tyndago (Oct 24, 2002)

ATCO said:


> Hi Sean, don't dispute your sizing figures at all.
> 
> GT37
> and the GT30;
> ...


If you like Sunoco , I wouldnt switch to C16 just to switch. I like C16 and its not too hard to get , but you should try to stick to one fuel. VP has some other new stuff called Q16 that is supposed to be ok. I have never tried it.

What are your sources for these compressor maps ? As far as I know , HKS doesn't release compressor maps. 

Looking at the numbers - one of the 3037S , and at least one of the 3076 are the same turbo. If they are different , they are different by about maybe 20 hp each. No real big difference in an 800 hp-900 build.


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## ATCO (Feb 2, 2003)

Where did I get them from? That's a brain racking question Sean! I tend to save them to file if ever I come across any as they always come in handy.

The GT37 originally came off :: Limit Engineering ::

The GT30 (and the GT37 is also on) Compressor Maps

That site also provides a useful explanation of how to read compressor maps if you want a headache.

Luckily I have both sites buried in my favourites so could pull them back up!

Your 3076 max pressure looks like 4, so 3x14.7=44psi

37 with 82mm is about 3.5, so 36.75psi max pressure. Although it is true to say that for the 82mm the corrected flow is comparable. That housing with the 0.54A/R really bulges the curve, wonder what a 3076 would be like on that build? FYI I think my 3037S are running 0.6A/R.

the 30 is similar but looks like its down at around 52. For those that do not know, the 125000 figure is the wheel speed. 

I have an ATP dyno comparing a 3037S with a 3071, not much in peak power difference at about 10, but the torque is miles better up to about 6500.

DaveG


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## GTR R34 (Oct 2, 2002)

ATCO said:


> Cord, damn good question, Rod isn't paying you enough!
> 
> As we are down into the weeds and where the "Tuner tricks" lie, i.e. those who really know how it works.....
> 
> ...


Your car is insane.
But why are you still runnnig stock brakes on the gtr?


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## ATCO (Feb 2, 2003)

As I frequently told Gary Passingham (GTaRT), brakes only slow you down!

Although I've been persuaded to upgrade to at least StopTech's, would have like Mov'IT Ceramics but the price really is insane, after I came under the bridge at Silverstone @ the JapShow doing around 160, put my foot on the brakes and it just went straight to the floor!

Only just made the turn at the end..............

The Brembo's in truth are fine on the road because they get chance to cool, but the GB's performance is too much for them on the track, not lasting even three laps of the Silverstone short circuit.

DaveG


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## tyndago (Oct 24, 2002)

ATCO said:


> Although I've been persuaded to upgrade to at least StopTech's,


That would be "downgrade" to Stoptechs. We tried them under real race conditions. The rotors warped easily . The Brembos are more expensive , but they don't do the same crap that the Stoptechs will do in one weekend at the track with a 3000 lb , 500 whp GT-R. 

If you do anything , change the fluid to Castrol SRF , put some ducting on the car , and some aggresive pads. Thats enough for most weekend type people. Most people NEVER get the ducting right. If you cool the rotor , the car will stop. If you use SRF , its expensive, but it really does work. We used Motul 600 most of the year, switched to SRF and really noticed a difference. And thats with bleeding the brakes after every single session on track.


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## Cord (Aug 21, 2002)

tyndago said:


> That would be "downgrade" to Stoptechs. We tried them under real race conditions. The rotors warped easily . The Brembos are more expensive , but they don't do the same crap that the Stoptechs will do in one weekend at the track with a 3000 lb , 500 whp GT-R.
> 
> If you do anything , change the fluid to Castrol SRF , put some ducting on the car , and some aggresive pads. Thats enough for most weekend type people. Most people NEVER get the ducting right. If you cool the rotor , the car will stop. If you use SRF , its expensive, but it really does work. We used Motul 600 most of the year, switched to SRF and really noticed a difference. And thats with bleeding the brakes after every single session on track.



What he said, exactly. 

If you do upgrade personaly i would use Alcon, Grex, AP or Brembo (probably in that order as well!)


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## Kevingo (Feb 21, 2006)

Totally Agree!

No Stoptech for me!

AP or Alcon (Y)


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## ATCO (Feb 2, 2003)

It's interesting you should all say that, StopTech seems to have people in two camps, either love them or hate them!

Warped rotors Sean under track conditions also seems to be a function of AP's too. Which particular ST discs did you warp? I know they come in various sizes, the 35 seemed to be the best option. I've not bought by the way so still have the choice!

Cord, why do you think Alcon are the best option?

In all instances I'm very much aware its the heat that does it, hence the MOV'IT's being on the wish list, but they are seriously expensive stuff, I can have others all round for just one and a bit corners theirs!


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## skyrocker (Feb 14, 2005)

The standard 33 brembo 4 pots front brakes are totally crap as we all know (IMO they are plain dangerous if proper braking above 200KMPH/125MPH is required), so considering that, changing to slowtechs would be a step forward  

On a more serious note: I can confirm Sean's findings about the fact that Stoptech rotors warp easily.

Henk


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## Cord (Aug 21, 2002)

I don't think AP's discs are all that good either, they can be prone to cracking unless you have the option of storing them outside in the rain for 8 months before you start using them.

I like the Alcon monoblocks cos they are a well engineered caliper, not too heavy and very little flex. The full kit (front 6 pot rear 4 pot) seem very well balanced.


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## Smokey 1 (Nov 1, 2005)

Any more development news Dave? when will the Garage Bommer be out next?
did you change the brakes to stoptech's ?





Smokey :thumbsup:


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