# LPG for R35 .. thoughts



## borat52 (Jan 29, 2006)

OK guys I'm preparing to get my head bitten off here but I've owned quite a few LPG cars (a 235,000 XJR and my current GS430 being noteworthy expamples).

I'm considering converting my R35 to LPG, the car is a 2009 with 16k miles and running stage 2 atm so close to 600bhp I would have thought.

Its unlikely I'll get a system to support 600bhp but I do know they can switch back to petrol at high load so I'm thinking of a system that could run on gas up to 300bhp then switch back to petrol when giving it some.

Does anyone have any experience or advise on this (other than just don't do it becuase its never been done before)?

I know LPG can kill valves, anyone know the approx cose of a complete valve overhaul for the R35?


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## Adamantium (Jun 24, 2002)

Get out, don't let the door hit you on the way!


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## TAZZMAXX (Mar 9, 2010)

There's a guy on here called Edward (posts as MobileLPG) who may be able to help. If you search, there is a thread about converting Skyline's to run on LPG as well. I'm sure R32 Combat had one of his Stagea's converted for LPG as well. It's doable but you may find yourself being the first. The biggest thing I would think being against it is the fuel tank will be so close the transmission so you will be fighting the heat it gives off?


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## Adamantium (Jun 24, 2002)

Fuel tank is also not that big for the fuel consumption. Add in the lower calorific value of lpg and you will need an extra tank. No spare wheel well, so you'll lose boot capacity.

My main concern would be the reduction in value, but if you intend to run the car into the ground anyway, why not! I'd imagine on a gtr it would pay for itself quicker than on many other cars.


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## Trev (Nov 1, 2003)

Can I ask a question.

Why are people buying GTR's then wanting to worry about fuel economy?

Odd.


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## Adamantium (Jun 24, 2002)

Some people love the car but hate the running costs, you could argue that an LPG conversion lets you have both.

In the states, the car is much cheaper to run because of the price of gas. If you whacked the price of gas up out there, people would complain. Just because you have to pay the cost, doesn't mean you can't be bitter about it.


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## Neanderthal (Apr 5, 2013)

I've had mine 4 weeks, filled up 4 times lol
My previous car I'd have filled up once.

It's a pain, but you should go into ownership of these cars with your eyes wide open.

To the OP, you'd be better off buying a cheap diesel to commute in and save the GTR for the weekend.


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## ASH-R35 (Jun 7, 2013)

Neanderthal said:


> I've had mine 4 weeks, filled up 4 times lol
> My previous car I'd have filled up once.
> 
> It's a pain, but you should go into ownership of these cars with your eyes wide open.
> ...


Only 4 times in four weeks?...I managed three tanks in my first week lol...and that was using it purely for pleasure purposes!


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## wmd_gtr (Jan 15, 2013)

Save yourself from the hassle, put the money it would cost you to one side and use that money on petrol


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## ROG350Z (Jun 15, 2008)

Adamantium said:


> Some people love the car but hate the running costs, you could argue that an LPG conversion lets you have both.
> 
> In the states, the car is much cheaper to run because of the price of gas. If you whacked the price of gas up out there, people would complain. Just because you have to pay the cost, doesn't mean you can't be bitter about it.


I agree - I am chuffed to bits with my new map which appears to do 26MPG as opposed to historic 21MPG on a run. Just because an owner can afford it doesn't mean to say saving money on Motorway etc isn't smart/desirable. No one got wealthy by pissing money away if they don't have to.


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## Trev (Nov 1, 2003)

I understand.

Still think its part and parcel of owning one, pros and cons ect.

Still, get around it and I say well done!


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## charles charlie (May 3, 2008)

Better off swapping the engine for a 1.8l diesel and flogging the original.

LPG.

Seriously :runaway:


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## borat52 (Jan 29, 2006)

Appreciate the advice here guys.

Please don't get me wrong, if its a no go I'll stick with petrol but I dont want to drive a diesel to work daily and if there is an option to pay half price for petrol then I would prefer that option to paying full price. 

Boot space is really of little concern and I drive past an LPG pump on the way to work daily so filling up often due to a small tank is not the end of the world. 

If we can disregard the 'why would you buy a GTR and worry about petrol?' comment (to those people please call me to arrange your insurance as I'll gladly take a £1k commision for arranging it - you get my point ) and stick to the general thread of what would be the problems and any experience people have had with other high power cars on LPG.

I see the car as a keeper for me and that means putting another 50k miles on it with potential savings of £10k.


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## TAZZMAXX (Mar 9, 2010)

http://www.gtr.co.uk/forum/167699-converting-lpg.html?highlight=converting+a+skyline+to+LPG
http://www.gtr.co.uk/forum/152914-1...pg.html?highlight=converting+a+skyline+to+LPG
and this is the one I remembered
http://www.gtr.co.uk/forum/128705-lpg-converted-gtrs.html?highlight=converting+a+skyline+to+LPG


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## borat52 (Jan 29, 2006)

Tazz,
Great links and I've made some enquiries with those members who seem to have some good knowledge.

If it goes ahead then I'll definaltely keep everyone posted here.


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## Nedzilla (Feb 10, 2012)

Neanderthal said:


> I've had mine 4 weeks, filled up 4 times lol
> My previous car I'd have filled up once.
> 
> It's a pain, but you should go into ownership of these cars with your eyes wide open.
> ...


I got through a full tank yesterday! 250 mile round trip to litchfields then saw off what was left at night trying out the new mods which included a very interesting encounter with a big bike!


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## TREG (May 20, 2004)

I guess it depends on how much the Lpg system costs and how often you use your car to make it pay?


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## Takamo (Oct 18, 2005)

I've heard it all now...... Don't degrade please just buy your self a cheap diesel corsa or something


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## TREG (May 20, 2004)

TREG said:


> I guess it depends on how much the Lpg system costs and how often you use your car to make it pay?




But then you will have more miles on the 35 so its will be worth less anyway. So really only worth fitting lpg if you are keeping the car for 5 years or more otherwise there is no saving.


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## borat52 (Jan 29, 2006)

Takamo said:


> I've heard it all now...... Don't degrade please just buy your self a cheap diesel corsa or something


I've already got a Lexus that will do 27 mpg @65p a litre so I've no interest in another vehicle.

I want to drive my GTR at 65p per litre if I can.

If its not for you guys I respect that but in the interest of pushing something out there that AFAIK has not been done before on an R35 it would be nice to draw on and knowledge in the field before going ahead.


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## CT17 (Mar 25, 2011)

Agree with some points mentioned.
How many miles will you need to do to get the cost of the conversion back plus any damage done to resale value?
Is it really cost effective?


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## Alexinphuket (Jan 25, 2012)

LPG is even cheaper if you fill the car up yourself at home. Buy a 47ltr propane cylinder, turn it upside down and connect pipe work and pump. Tax in heating LPG is only 5% very cheap motoring. However, I do have to agree with other peeps, half the fun of owning a GTR is fantastic performance, it may be doable but can't honestly think why you would want to, the setup may be good enough for 300hp, but if you press the throttle and give it a but more oomph, the system would changeover from lpg back to petrol, most LPG cars I have been in have been less than transient switch and cough and splutter when going from 1 fuel to the other. iit may end up becoming frustrating, especially if you are trying to overtake. Best of luck though, subscribed.


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## KAT (Apr 7, 2011)

I've always thought that an extra economical car makes more sense as the savings you get from fuel, running costs and depreciation due to mileage will mare than cover the extra car. 
Only problem is my extra run about just now is a Shogun :chairshot
J


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## R32 Combat (Jan 29, 2004)

LPG rules OK. I converted my Stagea, and a few other cars. I even had a RB30 Nissan Patrol on LPG for a short while.

There is nothing wrong with LPG, I ran 300hp with mine. You should really map the car for it as the burn rate is difference from petrol. You'd need a 2 map ECU ideally.

It's cheap, it clean, its green and you can get more power than petrol, sure the tank is heavy as hell and they take ages to fill up, but apart from that, its all go go go, fill, go go go.


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## Steve (Sep 21, 2001)

borat52 said:


> OK guys I'm preparing to get my head bitten off here but I've owned quite a few LPG cars (a 235,000 XJR and my current GS430 being noteworthy expamples).
> 
> I'm considering converting my R35 to LPG, the car is a 2009 with 16k miles and running stage 2 atm so close to 600bhp I would have thought.
> 
> ...



Don't be stupid, the GTR is a car not a gas propelled cigar lighter!!!:chuckle:


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## Verinder1984 (May 8, 2011)

oh my!

GTR economy is pretty good! i have driven bentley GTs and Aston DB9s, now those cars guzzle!

would make an interesting read to hear how you get on if you do decide to convert it.


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## WARP SPEED (Aug 14, 2012)

If you can get it to run more than the standard torque and horse power then yer go for it.


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## ACspeedtech (Aug 25, 2011)

Using LPG on performance turbo cars is something I've had quite a few dealings with, the weight of the kit/tank is the only difference (30kg-ish) as you'll be carrying LPG instead of Petrol. With the modern systems there really is no performance downside, in fact there may be an improvement to be had.
Few pointers... Be sure to use valve lube if needed (or even if not, just to be sure), also make sure the install is done by an approved place who can certify it for your insurance company.
The limitation is that most vapourisers will only allow you to use up to around 14psi of boost, with most guys running switchable maps though, this isn't an issue, and you could use one map to run a lower boost level, but additional timing and make the most of the higher octane rating (using a switchable output in the ecu to trigger on the lpg system in that map mode too maybe?)
Very interesting, if someone wants to do a lot of miles in their GTR then having the equivalent of 40-50 mpg whilst cruising then why not? You can always switch to petrol and high boost to go 'playing'!


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## tarmac terror (Jul 16, 2003)

ACspeedtech said:


> as you'll be carrying LPG instead of Petrol.


Not so...you will need to carry both. And quite a reasonable amount of petrol too in a dual system....

Technically, converting ANY car to LPG is straightforward and uncomplicated. The reason they are popular with estate and 4x4 drivers is that they can accomodate the tank. A GTR, on the other hand, would most definately not.

Drive your Lexus more and use the GTR less.....saving's RIGHT THERE!!!!



TT

P.s I'm off to trawl the Ariel Atom forum to see if anyone has asked about converting one of them to LPG...just as bonkers an idea as doing a GTR IMHO..


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## ACspeedtech (Aug 25, 2011)

You will need to carry 'some' petrol as the system will fire up on petrol and warm up to around 60 degrees C before switching over, however you will not have any need to carry a full tank of petrol around.
The next step forward is for the liquid LPG system to be available where you can totally remove the petrol system/tank and replace it.
There are many many sizes, shapes and options on tanks. Installed in the boot which is designed to carry weight there is not a problem.
If a person does not have the luxury of a second car, enjoys driving the GTR, but has need to cover a lot of miles on the motorway, then why not? Putting a large tank into an ariel atom is not a viable option, in the same way I don't imagine we'll be seeing many LPG motorbikes towing a tank around, but in an 1800kg GT car, 30 kilos weight and only being able to carry 2 sets of golf clubs for the improved economy on a motorway run may be a fair trade for some people.


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## tarmac terror (Jul 16, 2003)

Jeez...Atom comment was as tounge-in-cheek as it could possibly be!!!

The OP HAS a second car which, if he is so concerned about fuel costs, he should utilise more to offset the cost of ownership...

TT


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## car killer (Oct 27, 2005)

I say go for it.
why bother driving around in a diesel when you have a GTR at home ?
Some people (most definitely not me) dont want to thrash around every time they use their GTR. What if your a motorway cruiser why not cruise at equivalent to 40mpg. Makes more sense than doing it at 20mpg..
some people would rather use the GTR every day rather than have it sat as a garage ornament.
Go for it and keep us I formed of the results from it.


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## car killer (Oct 27, 2005)

https://www.youtube.com/watch?v=DBvQmJ34mRQ&feature=youtube_gdata_player

not bad for crappy lpg eh lol


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## borat52 (Jan 29, 2006)

Well having spoken to Phil at Gas Tech in Warrington I've found out that he has had some impressive results on other turbo performance cars including 300+bhp impreza's. If we take a 300bhp 4 cylinder impreza and scale it up then 450bhp across 6 cylinders should be possible on LPG. In fact its more of a boost pressure issue apparently as from my limited understanding the gas cannot be supplied to the engine if there is too much pressure on the air side due to the way that gas does not have a pump but instead relies on pressure from the tank.

In any case 1 bar of boost seems to be easily possible so our talks so far have focused on getting a solid 450-500 bhp on LPG (so stock power output) but building enough headroom in the Gas spec to aim for 600bhp (stage 2) if we can.

Possible issues:
- LPG is known to cause valve seat recession, reportedly due to a lack of lubrication in the LPG as opposed to unleaded so a flash lube system will hopefully cover this.
- LPG burns hotter than petrol (although for a shorter period so the actual energy release in total heat should be similar) which may in fact be the cause of valve seat recession that is attributed to a lack of lubricant. It's hard to see a way around this other than to burn out the valves and rebuild them with hardened valve seats if this does occur.
- Plasma coated cylinder bores - will the LPG destroy these?
- Weight of the tank - its actually possible to fit a 102l donut tank in the boot, this is obviously quite a lot of weight to be carrying over the rear axle and its also relatively high in the car, but the car is front heavy anyway and there really is no other way around this. Someone hardcore might be tempted to remove the rear seat and fit there which would be a lot better for weight distribution but I want the rear seats retained.

I'll open a thread in the projects section once I've satisfied myself that its mad enough to work!


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