LPG Conversion
Author
Discussion

rthurbin

Original Poster:

2,782 posts

243 months

Sunday 30th October 2005
quotequote all
I currently drive a vauxhall vectra grey box and hate every minute. Buy the end of March I will say goodbye to the gutless piece of miserable motoring and say hello to a £20k car (I am opting out of the company car scheme).

I do about 25,000 miles a year and can virtually choose the car I want.

I have managed to narrow it down to the following choices:

S8 (2002 with 50k miles)
M5 (2000 with 50k miles)
Monaro (2004 CV8 with 10k miles)

The monaro is in the lead at the moment and I will probably end up buying one.

As I do the high miles a LPG conversion will pay for its self in about 9 months!

Anyone done this to their car?

Does Vauxhalls warranty still stand?

Any other things I should consider about a LPG conversion? Longevity?

raggyman

2,317 posts

264 months

Sunday 30th October 2005
quotequote all
Not sure that it can be done on the 5.7, as far as my mates experience back home, they won't convert it.

stevieturbo

17,916 posts

268 months

Sunday 30th October 2005
quotequote all
The plastic inlet manifold is a potential problem. Small backfires seem to be an issue with some LPG conversions. With an alloy inlet, its no big deal. With plastic, its likely to blow it apart.

Apart from that, there is no reason why it cant be done.

uk hsv

1,692 posts

274 months

Sunday 30th October 2005
quotequote all
LPG and the LS1 don't mix.......

HSV state their cars cannot be run on LPG.

The main problem is the LS1 uses a plastic intake manifold that could fail if the car backfires into the inlet track......

vy2clubby

957 posts

243 months

Sunday 30th October 2005
quotequote all
Why buy a serious performance car like a HSV or the (slightly)lesser Monaro and thottle it back with inferior fuel. If you are worried about fuel consumption then buy a 1.5 litre lawnmower - to quote the old Rolls Royce arguement ' if you need to ask about the fuel consumption, you obviously can't afford the car':-)

308mate

13,758 posts

243 months

Sunday 30th October 2005
quotequote all
I cant help also thinking its a slight contradiction, less power, less efficient (but cheaper fuel.)
Would you still have gone down the LPG road had you bought the M5? I cant see that being an easy conversion.
If youre still keen though, have a look at www.gasresearch.com.au
Im pretty sure they know a bit about gassing Holden/Chev V8s.

PB

rthurbin

Original Poster:

2,782 posts

243 months

Sunday 30th October 2005
quotequote all
If it cant be done, then that answers it! Thanks.

As for the contradictions... I accept that when you buy the monaro you dont expect it to be cheap to run. I am sure I will be on first name terms with my local garage.

If there was a way to half the cost of fuel for the '000s of motorway miles I will be doing, stuck behind some w**ker who doesnt like using lane one, or the predictable stop start around the m25, then I dont see the problem with it.

If it pays for its self and doesnt detonate the car then surely that is a good thing? If you want to have a 'play' or do some laps on a track then you can turn it off!

Anyway its academic. Thanks for the replies.

Regards,
Richard.

sjc

15,552 posts

291 months

Sunday 30th October 2005
quotequote all
Richard, I think a very valid point here is that apart from fuel comsumption( and it's not THAT bad for what it is) an 04 Monaro will be way way cheaper to run than an older S8/M5 in maintenaince etc.The M5 in particular holds some real horror stories. And of course you'll have the balance of the manufacturer warranty as well. Stick around on this forum and I'll be surprised if you find any unhappy owners.Pick your dealer carefully, ( not necessarily your local one,Greens and Picador spring to mind)and add a Wortec re-map,exhaust and rip-shift for about 2 grand, and for approx £22K you will be gob-smacked by the type of car you end up with.

stevieturbo

17,916 posts

268 months

Sunday 30th October 2005
quotequote all
Its an internal combustion engine. Of course it can be done.

As for it being an inferior fuel ? Not so. It may contain less energy content per litre, but its a higher octane fuel.

So if the engine is tuned to run on LPG, it wont lose power. It will use more fuel than equivalent petrol to make the power, but it still has the ability to make good power. A forced induction engine could exploit that a bit better.

roger440

160 posts

264 months

Sunday 30th October 2005
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There is actually a ute in this country fitted with Gas on an LS1. And its hothouse green, Grrrrrrr!

Don't know anything more than that though sadly. As Stevie says it will be possible, just needs a decent cast manifold.

308mate

13,758 posts

243 months

Sunday 30th October 2005
quotequote all
Where did you get your ute Roger? What spec is it? Got any pictures?

uk hsv

1,692 posts

274 months

Sunday 30th October 2005
quotequote all
these guys have done some conversions on UTE's... [url]www.p-i-fuelsystems.com/[/url]

roger440

160 posts

264 months

Sunday 30th October 2005
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Hi 308mate. The ute is a 2003 (VY) Holden SS ute in Hothouse green. Now has a remap, ripshifter and lowered with whiteline springs. I imported it myself in 2003 (new) before our government decided to make that virtually impossible! Came in from Perth.

Made my trip to OZ the most expensive holiday i ever had! Best car i have ever bought though!!!

Go here for a picture www.monkfishperformance.co.uk/about%20us.html

Boosted Ls1

21,200 posts

281 months

Sunday 30th October 2005
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LPG is higher octane like Stevie said and it's also very compatible with forced induction. No way is it the low power option. In fact on a boosted ls1 it's probably safer then petrol. I wanted to do this years ago using dual fuel injectors but got delayed. Aluminium plenums are available so LPG can be done.

Boosted.

stevieturbo

17,916 posts

268 months

Monday 31st October 2005
quotequote all
If I was doing it, I'd just use the plastic inlet anyway. If, or when it blew apart, then I'd worry about changing it.

I'd say modern gas injection systems would be less prone to backfires, and with the factory LS1's very mild cam profiles, it should be fine.

There are a few alloy inlets available, although most arent cheap..

Although using a carb inlet manifold, and adapting it to gas injection would make it relatively cheap, although perhaps more work.

slippery

14,093 posts

260 months

Monday 31st October 2005
quotequote all
For what it's worth, I had my wife's Discovery converted. There are loads of different systems around. Mine is a multipoint and the job cost around £2500. You can't even feel it switch from petrol to gas. Even if there was a slight difference that you wanted to remove for one of those 'high octane' moments, a press of the button on the dash will have it running on petrol in a split second (there are 2 tanks). The extra tank goes where the spare wheel is in most cars so you don't lose any boot space. You are just in a bit of a muddle if you get a puncture, although in reality most people still just lay their spare in the boot unless they need the space. The company that did mine are called Jaymic and I have had no trouble with it at all. More and more stations are popping up all the time so with a little bit of forward planning, refuelling is not a problem. If my Chevy was on the road, I would certainly have looked into getting that converted too. Another bonus you will have is a greatly increased touring range.

308mate

13,758 posts

243 months

Monday 31st October 2005
quotequote all
Roger440! I love the hothouse Green - always wondered if it would affect the resale but at the end of the day it looks mint. Yours has a really nice stance, not too low yet business like. Im from Perth myself. Id be very interested to talk to you about the mods, how you imported it and any problems you had. Im some way off getting one right now (have to clear some debts first) but its always good to chat about it - gives me something to work towards - my company car is a bucket.

PB

308mate

13,758 posts

243 months

Monday 31st October 2005
quotequote all
Roger440 (sorry to take this OT guys) - check out the Holden section of the Pistonheads classifieds. There is a guy there selling his red ute (maybe someone from here?) and his No plate is H15 UTE! He may let it go seperately if hes flogging the ute anyway? Id get it myself but it would silly on my Peugoet and Id be depriving someone else!

PB

roger440

160 posts

264 months

Monday 31st October 2005
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308mate, there have been several utes for sale recently. Number plates with ute in are quite cheap, usually no more than £500, cos it means nothing to most people.

As far as getting a ute, i would advise you buy one that is here already. SVA is a nightmare now, unless you want to bring in an 05 maloo, in which case you need to talk nicely to Stu Harris and see if you can use his model report.

roger440

160 posts

264 months

Monday 31st October 2005
quotequote all
Feel free to give me a ring to discuss if you want. Phone number can be obtained through the Monkfish ad at the top of the page.