Straight LPG turbo for and against?
Turbo Mini Forums

Now I know some of you will think it’s a crazy idea but there are some big advantages to it

I have looked throw the Search and found some good things, I really am very tempted to do it to a mini, I’ve help a bit with my cousin doing it to a 4L straight 6 Ford Falcon over here and it is very impressive.

Some of the main points that stand out are the octane rating of LPG. Not sure if it is the same over your side of the world but the ‘LPG’ we buy from a serves station is called auto gas LPG, which is about 80% propane and 20% butane. This means depending on how much they mix the propane down will change the RON level somewhat. I have been told from same gas fitters that the minimum RON you can expect is 108 and up to 114 normally from a BP or Mobil.

Now if you filled your cylinder up with real LPG not mixed down, same as a BBQ gas bottle your looking in the order of 120+ RON. Now there has got to be some big advantages in that 20PSI boost on 9:1 Comp should make a really nice car to drive off boost and silly on boost.8-)

LPG runs cooler the leaner you burn it so it’s not like petrol that will melt piston if you lean out in the rev rang. With an Impco mixer and converter it is easy to tune as there are only three screws to set the mixes, idle mix, part throttle and WOT. There is also diagrams and springs but generally would need to touch them. So it can be set up in a day with a wide band O2 sensor, as we did on my cousin’s turbo Ford Falcon here.

ATM our government is giving a rebate of $1750AUD when you install gas on a road reg car. So it is about $500AUD for a new tank, $500 to get the right size mixer and converter so leaves $750 to get the gas fitter to run the gas line and fit the tank.
The LPG mixer completely with all the air going in the motor so it means a lot more even AFR between all the cylinders, which can only help with power.

Yes there is less energy density with LPG over petrol so for a given volume of air it will have to displace some oxygen to get enough gas in the mix burn but with forced induction this isn’t a problem as we are ramming oxygen in to our mix anyway.

I’m thinking very much about doing it, with a blow throw set up of course. I have been talking with a guy here in AUS that did a straight gas turbo moke about 8years ago and loved it.

The only bad points Iv really found would be the weight of the gas tank (about 30kg) and not being able to fill up at the side of the track..

Do you guys know of anyone with one running ATM, how has it been running? Would you do it agen?

Nathan.

The only downside...apart from making it work.

Is that injecting liquid fuel spray, or a carburettor...does have an intake charge cooling effect. LPG wouldnt offer this, so more work might need done with temperature control.

Unless of course you get a liquid gas injection system....now that would be good.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

The only downside...apart from making it work.

Is that injecting liquid fuel spray, or a carburettor...does have an intake charge cooling effect. LPG wouldnt offer this, so more work might need done with temperature control.

Unless of course you get a liquid gas injection system....now that would be good.


And here in the UK. Gas isnt very cheap, and the government give us no incentives to use it.
And the level of technology isnt up to the same standard of that available in countries like Aus.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

I think Robert's punto headed turbo engine is cooking on gas.

If im not mistaken Robert has built a 16 valve engine with a fiat head and a turbo, that is running on LPG. (There was a video of it running in his back yard)
I dont think it has run in anger yet but if his other car is anthing to go by it should work well.

"So wat we gonna do tonight Brain?"
"Same thing we do evernight Pinky!"
"Try to take over the world!"

I believe that roberts engine is running on propane not lpg.

Close enough to the same thing.

You can fill an "LPG" car via the big red Propane cylinders.

Just dont tell our robbing scummy HMRC

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

It is running on propane...will never forget that smell!

Edited by matty on 8th Aug, 2009.

https://www.facebook.com/pages/Fusion-Fabri..._homepage_panel

www.fusionfabs.co.uk



1/4mile in 13.2sec @ 111 terminal on 15psi

I was looking through an Aussie version of Street Machine magazine and I noticed an article on a proper liquid injection setup for LPG. From what they discribed it is almost DIY as far as the ease of instalation goes (only your not allowed to do it yourself of course) and it seems a fairly flexible system. At least your in the right country for LPG systems, there isn't much in the way of LPG in the UK.

LPG is an excellent fuel choice for a turbocharged motor.
Go for a dedicated LPG setup, not dual fuel.

I'd recommend having a look at this setup:

Been considering it myself.

Note that the rules on LPG conversions in Aus are about to change with respect to emissions testing (were previously exempt from any testing).

Interesting stuff. Whilst it's cheap, you can bring the cost right down by having a DIY home fueller. My gripe is the same with alcohol. The calorific value is low, which means that although you can run more boost and more advance/cr, the actual thermal output and energy for actual expansion to happen is less.

Do a thought experiment for a second.... you would use more LPG/alcohol in your car...how big is the tank? My mini was doing about 14mpg last time I looked. More like 10 with gas. Go nice in your daewoo though.

Bugger off, I'm getting there.

Just looking at fuel prices where I used to live in Oz, ~50p a litre! 25p for LPG, why did I ever leave!

i would have thought LPG would have had a built in cooling effect, seeing as it is a compressed gas anyway. You need a vapouriser circuit just to get it up to temp to convert to liquid...otherwise it ices! I know having installed a few lpg kits. Octane is higher, but power output is lower (about 10%). Ignition advance (LPG likes this) changes can pull this loss back though. ) Thats why the twin ignition map switch option in megajolt has a use, switching between fuels.

Got to watch the backfire problems though (ouch on the turbo vanes). I used to fit a elasticated bungie on the air filter to stop it blowing the filter box apart (usually because the lpg was icing)

Cheers,

D

Edited by manifold on 11th Aug, 2009.