WRX LPG conversion?

[brum]

A mate of mine is running an 05 plate WRX which he is using as a company car – unfortunately due to the mileage incurred it is costing him an arm and a leg in fuel.
He is considering getting rid in favour of some kind of diesel repmobile.
Since I am forced to drive a diesel repmobile and I rather enjoy taking his Scooby out for a blat at the weekends it would be a shame if he had to get rid of it.

We were chatting last night about the possibility of converting to run on LPG in order that he can hang onto it. It has raised a few questions.

1) Has anyone undertaken an LPG conversion on a WRX if so what MPG are you achieving?
2) What’s the impact on performance (I have hear a loss of 4bhp but not sure if this is accurate)
3) Does in impact the dynamics of the car at? Does the LPG tank affect weight distribution adversely?
4) Is this just a bloody stupid idea?

Thanks Guys

[GravelBen]

Never really heard much about people converting turbos to LPG, but its fairly popular with the big aussie 6's. My parents use to have a 4.1 XF Falcon converted to dual fuel (petrol tank and LPG tank), iirc it made a bit less power on LPG but more low-down torque so it wasn't all bad.


In a recent NZ Autocar fuel economy test an LPG 4.0 Ford Territory (Falcon-based SUVish behemoth) cost less to run than a Honda Jazz

[cw42]

Quick search on Scoobynet produced this:

http://bbs.scoobynet.com/scoobynet-general-1/63268...

Think you'd be better getting a second car and keeping the scoob for the weekend

[GTS Turbo]

there was a scoob impreza wagon wrx with a LPG conversion not long ago so can be done

[ScoobieWRX]

Why mess with the Scooby....Sacrelige!!!

You've gotta have a big LPG tank in the back taking up loads of space not to mention the extra weight of it all. You don't buy a WRX for economys sake, it's there to be driven and run on the good stuff not fart gas!! What an awful thing to do to it.

Lets get a Bugatti Veyron and see if it will run on steam power

Tell him to get a quick diesel, there's plenty of choice, and leave the Scooby alone

[EDLT]

Keep it as a second car and get something else to pile the miles on, whats so bad about diesel remobiles if all you are using them for is basic transport?

[Vixpy1]

I had a customer with a LPG 200sx, actually made more power on lpg than vpower when tuned for the fuels!

[ScoobieWRX]

If it was such a great conversion LPG Scoobys would be commonplace, however....they aren't, and i think for good reason. There are still very few LPG stations around and LPG conversions have been around a very long time. The cost of a good conversion can be a couple of grand, so just those two reasons alone make it prohibitive. Equally i don't fancy having a bad rear ender one day when i have a bottle of compressed LPG in the boot just waiting to go bang. Bugger that!!

Although it might be a novel idea to have a Petrol tank and LPG reserve i still think you're better with a diesel. Much more MPG, and then you make your own BioDiesel, which will cost you bugger all for the first 2500ltrs, after that you'll only be paying about 51ppl in tax, which is still cheaper than LPG due to the high MPG you get with diesel....if you want to be economically minded that is.

I'm looking forward to seeing a Diesel Scooby come to the market as i plan to make my own BioDiesel when that happens. Very easy to do too.

Edited by ScoobieWRX on Sunday 16th September 01:03

[wrightyrs]

If you go to Europe you'll see loads of cars with LPG conversions.

As in Europe the different goverments have encouraged the use of LPG as an alternative to Petrol and Diesel.
The phobia towards LPG in this country is lack of information on the subject,as its never been really actively sold to us.

I have a turbo engined car running 200+bhp and have had it running on LPG for nearly 100K miles with no problems what so ever.
I have done trackdays in it and many laps around the Nurburgring.

It makes having the car i have affordable for me to run due to the lower cost.

I will admit i do over 40K miles a year in my cars and for the length of time i keep them the conversions pay for themselves and it means i don't have to drive around in a diesel.

Its not for everyone and its only worth it if your gonna be doing big miles and are going to keep the car for a while.
Or buy a car thats already be converted,as you never get the money back in the sale price when yhou sell them,means you can get some bargins secondhand.

[liner33]

There was a Skyline running on LPG,iirc there is a higher risk of det and LPG burns hotter than petrol so high exhaust temps may be of concern, may be ok for a totally stock car but i'm sure it will affect potential performance

Its hard getting an honest opinion though LPG converts and companies will tell you its fine and the more sceptic amongst us will tell you not to risk it

[emicen]

liner33 said:

There was a Skyline running on LPG,iirc there is a higher risk of det and LPG burns hotter than petrol so high exhaust temps may be of concern, may be ok for a totally stock car but i'm sure it will affect potential performance

Its hard getting an honest opinion though LPG converts and companies will tell you its fine and the more sceptic amongst us will tell you not to risk it

LPG reduces the chance of det as:
1 - it has a higher octane rating than petrol
2 - it is by definition a liquid gas, which when expanded in to the inlet, removes heat from the charge

Making your own biodiesel is a shit idea frankly. Unless you want an old Berlin taxi to smoke about in, any modern diesel reliant on high rail pressures and good quality fuel will get mucked up using such a fuel.

The idea of an LPG turbo'd car makes a lot of sense. Buying a crap car to notch up the miles completely defies the purpose of having the nice car in the first place. Believe me, I know, I bought a Corolla to keep the miles off my Celica, sold within 2 months as it made driving so mundane. Current car is a Golf GT TDi, not a patch on the Celica again and I'm really struggling to keep it just on the basis it saves me cash. Banging an LPG conversion in the Celica is on the table and under consideration, the advantage to the Scooby owner over my car would be at least theirs has a sizeable boot to sacrifice some space from!

[ScoobieWRX]

emicen said:

liner33 said:

There was a Skyline running on LPG,iirc there is a higher risk of det and LPG burns hotter than petrol so high exhaust temps may be of concern, may be ok for a totally stock car but i'm sure it will affect potential performance

Its hard getting an honest opinion though LPG converts and companies will tell you its fine and the more sceptic amongst us will tell you not to risk it

LPG reduces the chance of det as:
1 - it has a higher octane rating than petrol
2 - it is by definition a liquid gas, which when expanded in to the inlet, removes heat from the charge

Making your own biodiesel is a shit idea frankly. Unless you want an old Berlin taxi to smoke about in, any modern diesel reliant on high rail pressures and good quality fuel will get mucked up using such a fuel.

The idea of an LPG turbo'd car makes a lot of sense. Buying a crap car to notch up the miles completely defies the purpose of having the nice car in the first place. Believe me, I know, I bought a Corolla to keep the miles off my Celica, sold within 2 months as it made driving so mundane. Current car is a Golf GT TDi, not a patch on the Celica again and I'm really struggling to keep it just on the basis it saves me cash. Banging an LPG conversion in the Celica is on the table and under consideration, the advantage to the Scooby owner over my car would be at least theirs has a sizeable boot to sacrifice some space from!

I think making your own biodiesel is a great idea and makes a lot of economic sense too. Also the general concensus from people that make their own is that their cars run much better, and more smoothly than pump diesel. I've had a 1.9 TDi 130 and i thought that was pretty good for a small diesel engine. A friend of mine runs his TDi on home made Biodiesel and it goes really well. Also it doesn't smoke as much as when he used pump diesel. IMO the TDi is no old Berlin Taxi

P.S. there are only 2.5M vehicles worldwide using LPG out of the 100's of millions of vehicles currently on roads globally. Although LPG has a higher RON rating than petrol it suffers with a 4% power loss over petrol. The only way you get more power from LPG is by upping compression ratio in the cylinder Why would i want less power from my car?? RON numbers only indicate the antiknock rating of a fuel. Using a very high RON rated fuel doesn't create more power, only your knock sensor does that by telling the ECU to alter the timing,AFR and other parameters. MON rating has more to do with how much power your fuel will provide than RON.

You're wrong about the cooling effect of LPG too. The heat of vaporization of gasoline helps to decrease the temperature of the fuel mixture, producing a denser mixture. Although propane and methane have a higher heat of vaporization value, they are already in a gaseous state when inducted into the intake manifold therefore they do not provide this cooling effect. Introducing a liquid (petrol) into the cylinder creates the cooling effect.

I'll stick with Petrol

Edited by ScoobieWRX on Thursday 20th September 22:21

[emicen]

ScoobieWRX said:

emicen said:

liner33 said:

There was a Skyline running on LPG,iirc there is a higher risk of det and LPG burns hotter than petrol so high exhaust temps may be of concern, may be ok for a totally stock car but i'm sure it will affect potential performance

Its hard getting an honest opinion though LPG converts and companies will tell you its fine and the more sceptic amongst us will tell you not to risk it

LPG reduces the chance of det as:
1 - it has a higher octane rating than petrol
2 - it is by definition a liquid gas, which when expanded in to the inlet, removes heat from the charge

Making your own biodiesel is a shit idea frankly. Unless you want an old Berlin taxi to smoke about in, any modern diesel reliant on high rail pressures and good quality fuel will get mucked up using such a fuel.

The idea of an LPG turbo'd car makes a lot of sense. Buying a crap car to notch up the miles completely defies the purpose of having the nice car in the first place. Believe me, I know, I bought a Corolla to keep the miles off my Celica, sold within 2 months as it made driving so mundane. Current car is a Golf GT TDi, not a patch on the Celica again and I'm really struggling to keep it just on the basis it saves me cash. Banging an LPG conversion in the Celica is on the table and under consideration, the advantage to the Scooby owner over my car would be at least theirs has a sizeable boot to sacrifice some space from!

I think making your own biodiesel is a great idea and makes a lot of economic sense too. Also the general concensus from people that make their own is that their cars run much better, and more smoothly than pump diesel. I've had a 1.9 TDi 130 and i thought that was pretty good for a small diesel engine. A friend of mine runs his TDi on home made Biodiesel and it goes really well. Also it doesn't smoke as much as when he used pump diesel. IMO the TDi is no old Berlin Taxi

P.S. there are only 2.5M vehicles worldwide using LPG out of the 100's of millions of vehicles currently on roads globally. Although LPG has a higher RON rating than petrol it suffers with a 4% power loss over petrol. The only way you get more power from LPG is by upping compression ratio in the cylinder Why would i want less power from my car?? RON numbers only indicate the antiknock rating of a fuel. Using a very high RON rated fuel doesn't create more power, only your knock sensor does that by telling the ECU to alter the timing,AFR and other parameters. MON rating has more to do with how much power your fuel will provide than RON.

You're wrong about the cooling effect of LPG too. The heat of vaporization of gasoline helps to decrease the temperature of the fuel mixture, producing a denser mixture. Although propane and methane have a higher heat of vaporization value, they are already in a gaseous state when inducted into the intake manifold therefore they do not provide this cooling effect. Introducing a liquid (petrol) into the cylinder creates the cooling effect.

I'll stick with Petrol

The VW PD is a variation on a theme within diesel engines. Modern BMW engines etc with massive rail pressures suffer form clogged injectors with the use of biodiesel, even running higher proportion biodiesel from the pumps from brands like Tesco.

The LPG when injected is far cooler than the inlet charge even after passing through the vapouriser coil in the engine bay.

The only way you can get more power is by upping the compression ratio? Nah, I'll just take the easy option and run more ignition advance.

[ScoobieWRX]

I dissagree with your comments about the LPG cooling cylinders better than petrol because it doesn't, and i've stated the reasons why.

Perhaps i should re-phrase my comment and say that the best way to get more power from LPG is to raise it's thermal efficiency and you do that by raising compression ratios. Best way to do that is through a Turbo or Supercharger. That's a much more efficient way of extracting more power, and on top of that you would advance timing as much as you might do with a petrol engine. Generally speaking though running LPG on normal cars you would usually run the same ignition advance as petrol engine so if you wanted more power just by timing alone then you would have to up it considerably more than any petrol engine for the same effect and to overcome power loss.

LPG aside.....

My guess is that E85, when rolled out nationally will surpass LPG usage very quickly and become the prefered fuel over even 95RON or superunleaded. It takes very little effort or money to convert modern cars (a fraction of the cost involved with LPG conversions) to E85, and with RON values as high as 107RON for E85 i really don't think there will be any point in bothering with LPG, at all.

So...this LPG debate is a waste of time really as it'll end up dead in the water anyway. It's been around the UK for donkeys years and few people bother taking it up. I certainly won't be as i see it as a waste of time and money. If it was that great how come you don't see top fuel dragsters and super high bhp jap cars, rally cars, formula 1 etc..etc.. taking it up. As for Diesel... I think Puegeot and Audi Le Mans cars have shown it's winning worth, performance advantage and better economy over petrol enigined cars, and they run BioDiesel too

Oh yeah....I nearly forgot ...some UK bus companies and taxi firms run their buses/cars on LPG don't they. However...during the lifetime of your average bus/taxi they will have done millions of miles, so very long term i don't doubt it's cost effectiveness...but that's it

If you want cost effective...don't buy a performance car and convert it to LPG...how crap is that!! Buy a smart car and run it on thin air instead

[wrightyrs]

Well while LPG is still 50% cheaper than petrol and diesel it makes absolute sense to use it.

I have a car that runs like a normal petrol car,costs half as much to run and is still good fun to drive.

So as a everyday car it makes perfect sense for us high mileage drivers who pay for our own fuel.

Edited by wrightyrs on Friday 21st September 18:12

[ScoobieWRX]

wrightyrs said:

Well while LPG is still 50% cheaper than petrol and diesel it makes absolute sense to use it.

I have a car that runs like a normal petrol car,costs half as much to run and is still good fun to drive.

So as a everyday car it makes perfect sense for us high mileage drivers who pay for our own fuel.

Edited by wrightyrs on Friday 21st September 18:12

I totally agree with you, and as i've already stated, if you do lots and lots of mileage it will be very cost effective, as would a diesel though. It's a trade off between e.g. LPG does 25mpg but costs half as much as diesel although with diesel you'll get twice the MPG. It's swings and roundabouts. I would prefer diesel though because as soon as i buy a diesel car i will end up making my own biodiesel, so it will cost me almost nothing to run

[liner33]

I'd rather have a sensible car for the high mileage work, than run a sensible fuel in a fun car.

[tuttle]

liner33 said:

I'd rather have a sensible car for the high mileage work, than run a sensible fuel in a fun car.

erm.. IMHO this is the crux of the matter.
On the other hand. I have come across an Evo 5 & a skyline GTST with LPG conversions. Booth owners claimed almost 50% reduction in fuel costs with no appreciable loss to performance.

[liner33]

tuttle said:

liner33 said:

I'd rather have a sensible car for the high mileage work, than run a sensible fuel in a fun car.

erm.. IMHO this is the crux of the matter.
On the other hand. I have come across an Evo 5 & a skyline GTST with LPG conversions. Booth owners claimed almost 50% reduction in fuel costs with no appreciable loss to performance.

Yes it is , its also a case of whether you belive the claims , of the few run of the mill lpg vehicles i have driven i have certainly noticed a slight difference perhaps 5-10% less hp than their petrol equivilents.

With the cost of the conversions being around £2k i reckon you would need to do at least 20,000 miles just to break even.

[emicen]

liner33 said:

tuttle said:

liner33 said:

I'd rather have a sensible car for the high mileage work, than run a sensible fuel in a fun car.

erm.. IMHO this is the crux of the matter.
On the other hand. I have come across an Evo 5 & a skyline GTST with LPG conversions. Booth owners claimed almost 50% reduction in fuel costs with no appreciable loss to performance.

Yes it is , its also a case of whether you belive the claims , of the few run of the mill lpg vehicles i have driven i have certainly noticed a slight difference perhaps 5-10% less hp than their petrol equivilents.

With the cost of the conversions being around £2k i reckon you would need to do at least 20,000 miles just to break even.

4 cylinder conversions are closer to £1000 from most places.

20,000 miles is around 8 months commuting for me, and outside the southeast there are plenty of people doing that kind of mileages.