After seeing all the discussions concerning the "fuel of the devil" I wanted to know if anyone has converted their coupe to LP Gas. Its as cheap as chips out here, way less than half the cost of high grade petrol per litre.

I have read that you will require about 10% more of it compared to petrol but when the cost of LPG is $0.60 per litre against $1.55 per litre of petrol, it still looks economical.

If it has been done, what is the effect on performance and the cost to convert and does it effect the reliability of the coupe.
Cheers

Yes, it has been done, look for posts by a member called "kingpleb", He's no longer active in the coupé world though, I seem to recall that three engine failures made him lose the love.....

Yeah KP was the LPG and veg oil specialist many moons ago. Nice chap too. He did melt numerous engines in his quest to save a few quid though. I doubt it helped that he didn't get it mapped properly and he was running more than standard power with it.

Because of the sensitivity of fuelling on a turbocharged car I don't think it's the best application of LPG technology whereas in one of your native big, lazy Holden V8s it seems to work a charm.

Just be glad you dont have to pay UK prices for fuel - you'd add another dollar to that for 1 litre!

Yes i replaced an engine on Wills coupe (Kingpleb) but it was due to him running it out of oil.
The LPG nowadays isnt much cheaper than fuel.
On top gear they worked out it would take 70,000 miles to recover the initial outlay which doesnt include engine failures.
IMO not worth it.

AndyEssex runs dual fuel, petrol and LPG, and can toggle between the two. He has been for some time, and has had no issues in that time.

He'll no doubt chip in if he sees this post.

I believe there isn't much of an issue with the latest multipoint injected systems because the standard ECU is making all of the decisions on the fuelling, the LPG ECU seems to act as a bit of a slave.

Thinking about return on investment:
LPG Conversion cost: £1000
Petrol cost per mile: 20p
LPG cost per mile: 12p
Breakeven: 12,500 miles

Then there are the benefits of a cleaner running engine.
Longer life.
Fewer oil changes needed.

In Australia you can get a govt rebate of about $2000 for installing LPG. On a large car that does high mileage the cost benifet is well worth it. The majority of taxis on the road (like 90%) are 4L 6cyl Ford Falcons running on LPG. I have never seen a diesel taxi, diesel is too expensive.

However the injection systems employed are super low tech and use a lot more fuel because of it. But as you say when the fuel is cheap who cares. And on an aussie 6 the tech is tried and tested and reliable enough. For a performace car you are going to need a much better liquid injection system. This cost a lot more but they also use very little extra fuel compared with petrol. I remember a guy I use to chat too at the race track has a Datson 240z on gas and he could get a lot more power out of it than standard petrol.

If you are really interested I would check out some of the Aussie Ford forums. I'm sure someone has a Falcon XR6 turbo on gas.

Not necessarily doubting you as I haven't checked for years, but I would have expected the LPG conversion to cost nearer £2k?

You also need to take account of the fact that you can't always get LPG so will end up running on petrol for a chunk of the time (in the UK at any rate)

I run my daily runner, an Audi S8, which is a 4.2 V8 at 360 BHP, on LPG, there's very little loss of performance and it's 72p a litre verus £1.42 for super plus.

It paid for itself in 18 months.

It's a no brainer as far as I'm concerned.

My mate runs his 2006 Land Rover Discovery 4.0 V8 on LPG......unfortunately he hadn't realised that LPG doesn't lubricate valves in quite the same way and toasted a bank of valves. Still, it was only a £3000 repair bill, but on the bright side that did include the oiler kit that he should have added when the conversion was done. Don't notice any difference when switches between the two fuels.

The valve problem depends very much on the quality of the valve seats.

The Mondeo I did had to use an oiler, anything from VAG doesn't, I don't know about the Coupe. I'd hope being a turbo that the valve seats are of a good quality.

I could write quite a big piece on this subject as my
coupe has done at least 40k now on lpg which can be
simply switched to regular fuel on the press off a button (as Dan said, thanks Dan),
(Romano N sequential system). Basically it means i get
full coupe power on switched petrol, so about 250-260bhp
and works out as equivalent of 46 mpg after bashing
through a calculator.

Essentially i do most driving on lpg but when i want a blast i switch it over to super unleaded petrol, then switch it back again afterwards.

I have started quite a big write up but never got round
to finishing it and posting it.

I understand the Prins system is slightly better
with no power loss when in use.

A mechanic on another forum, scoobies, , 'Westwood2006' , has done the installation himself by attending a course and using his own car as the donar to pass the course, there's a thought.

Very good write up by him at -(warning pic heavy -good !)-
http://bbs.scoobynet.com/projects-40/881490-my04-wrx-ppp-lpg-skunkworks.html

page down about 4 screens and the write up starts.
He does go on about valve flash lube, mine doesnt have it and its been ok, but i cant really comment on that, all i know is its been ok without it.

Have a read and let me know if any questions/pics
might help more or perhaps drop Westwood2006 a mail.

just install the PRINS lpg system best on the planet it has a slave ecu that copies data from your original ecu...tried and tested on a audi rs6 560hp..its the only lpg system that uses KEIHIN japanese lpg injectors best on the planet

http://www.gasdoctor.eu/?CategoryID=242&ArticleID=138

A few months ago I was looking about £800 to convert a 4 cyl Alfa. I added a bit to account for the Coupe needing a 6 cyl system. I had an LPG station on the way to work, so did hardly anything on petrol.

My old Rover 618 did the same. At 225,000 miles the tappets had run out of adjustment and I had to start filing down the tops of the valves to keep it all airtight.

I got installed a Landi Renzo system about a year ago, little before the cam belt snapped...

Nothing to do with the LPG, of course. The engine was recently rebuilt and I've done about a thousand kilometers. It still needs to be tuned, but it works nicely.

Other from that, with our high fuel prices, LPG allows me to spend almost half the money as compared to gas, while driving the same distances.

It's my second LPG converted car (after a '00 Fiat Panda 4x4), so I definitely have a good experience to share.

Regards!
CJ