LPG and S2's

[Jonnybravo]

You're welcome mate ask me when you have any doubt, if I don't know the answer, well... I will search for it! yes please, let me know how's it going with the LPG setup!

cheers!

Out of interest which systems have you used ? I'm just queing for the ferry after doing a course at Eurogas in Holland and they have given me some good advice and also offered to help sort a map with a LPG cut off to stop any issues with the valves etc.. Eurogas are the sister company to Landi Renzo who I assume you do know of.

We have now tested the latest Prins system with the electronic flashlube on a Range Rover Sport with good results, the system isn't as mappable as I would like which is why I am swinging towards the Eurogas system, the only issue being the noisy bulky MED injectors they would prefer I used over the Khein injectors.

[diesel des]

My setup uses a kme system. Its great. Also i would say you need a wideband lambda kit to set the gas up best. You actually want to set the gas up LEANER under WOT that it is on petrol!! Not ritcher. GAs works differently. Leaner gives a cooler EGT not richer on gas. i run about 13-13.5 at wot. No problems. Its like 110 octane rember.... Most of the big gas gen sets i worked on ran Lambda 1 at full load. They ran 100% duty 24/7. no problem.

I actually notice a drop in power at full boost 5K rpm when on petrol. Yes more power on gas.

[Greg_S]

Im interested to see a few more details on these conversions too. Ive been looking at LPG kits again, especially since you can get vertical toroidal tanks these days too

[Dubbedup]

I test drove a S6 converted on LPG that was advertised on here, and it drove like a pile of crap...From 2k to 3.5k RPM it was jerky and undriveable and at 3.5k BANG...it was almost like the fuel map had sorted itself out and it went off like a scalded cat... It was like the LPG could not work under load...I would have expected for it to have switched to Petrol if it was having hardships running on gas, but no....There was obviously something well wrong with the install...

I have converted a couple of cars, both of them N/A, always seen turbo installs as a bit of a black art, I suppose that the introduction of LPG injection systems should take up some of the slack, but obviously not on the S6 that I had a drive in... Watching this thread with interest..

[Azman]

Yup anything that can make the day to day running of the S2 a bit cheaper for us all the bear would be a good investment. Also massive increase to the touring capabilities

[Jonnybravo]

My setup uses a kme system. Its great. Also i would say you need a wideband lambda kit to set the gas up best. You actually want to set the gas up LEANER under WOT that it is on petrol!! Not ritcher. GAs works differently. Leaner gives a cooler EGT not richer on gas. i run about 13-13.5 at wot. No problems. Its like 110 octane rember.... Most of the big gas gen sets i worked on ran Lambda 1 at full load. They ran 100% duty 24/7. no problem.

I actually notice a drop in power at full boost 5K rpm when on petrol. Yes more power on gas.

The innovate wideband we use does have LPG settings which are similar to your figures, we don't strictly convert vehciles to be on the lean side to gain power but we may on my own car.

I test drove a S6 converted on LPG that was advertised on here, and it drove like a pile of crap...From 2k to 3.5k RPM it was jerky and undriveable and at 3.5k BANG...it was almost like the fuel map had sorted itself out and it went off like a scalded cat... It was like the LPG could not work under load...I would have expected for it to have switched to Petrol if it was having hardships running on gas, but no....There was obviously something well wrong with the install...

I have converted a couple of cars, both of them N/A, always seen turbo installs as a bit of a black art, I suppose that the introduction of LPG injection systems should take up some of the slack, but obviously not on the S6 that I had a drive in... Watching this thread with interest..

Sounds like a naff conversion sadly, I did a S4 a few years ago and it was really good, a bit of a nighmare to locate install everything hidden but the car drove 100%, there are too many systems out there these days that are simply not upto the job, we only use 3 systems, 2 of which are suitable for turbo/supercharged vehicles.

[knobstar]

Interesting topic...

...I have a few questions:

1) What are the two makes of LPG system that you trust JB?
2) Can they be made to run on their own or do they have to piggyback existing ecu?
3) To that end; can a turbocharged car be made to run (reliably) exclusively on LPG?

Cheers,

Matt

[Jonnybravo]

Hi Matt,

We install BRC, AG, Eurogas and Prins, the AG and Eurogas are both for factory fit installs and are rarely used on anything else, the BRC system and Prins are both very capable systems for any engine and both offer a electronic flashlube system where a oil is sprayed into the inlet every so often for internal lubrication, this is quite a new design specifically designed for forced induction vehicles and we have so far used the latest Prins system which worked perfectly.

Flashlube isn't required for all engines, but its usually turbo or high mileage engines that benefit from using it so I would use it on my S2 for example.

All LPG ecus are piggyback from what I have seen, I have not seen a manufactured standalone kit although there are many older single point kits on cars that have had the petrol system removed. The only reason the cars remain dual fuel is to get the water system upto temperature to warm the vaporizer before switchover, starting on LPG can cause this unit to freeze and then you will be going no where, I've had cars which are only LPG and as long as you let them warm up the vaporizer won't freeze, infact our own Merc Sprinter is LPG only using a modern Prins system, obviously having petrol and LPG gives you far better range which is why I wouldn't advise removing the petrol system.

To sum things up there is no issues with using LPG on a turbo engine reliably, however if it was to be only on LPG you could have issues on cold start which is why I personally wouldn't do it.

https://www.gastech.org.uk

Lots more info on there and a few pics of conversions

[knobstar]

Thanks for the very informative reply, Jonny - I'll have to find myself a 'basic' petrol ecu to *******ise now

[Jamo]

How did this go? Was the S2 LPG converted?

[Jonnybravo]

Digging up a old thread as I hadn't replied to you Jamo.

Sadly I was made redundant in february so I never got the chance to get the car done, shame really as the new Prins system was looking to be excellent.

I could still do it if I could afford it but I got a cheaper daily runner which has saved me a fortune now the S2 only gets used at weekends.

[Le S2 Audi]

I find this thread interesting - but don't you lose power with a LPG conversion?

And if i may say why oh why do it to such a future classic

Sorry but I just dont get it.

Not wishing to upset anyone - just trying to understand the reasons why?

[Jonnybravo]

My only reason was simply that I wanted to use the car daily thus putting on a lot of miles, mechanically the S2 is good for it but its damn juicy so running it on LPG would of been ideal.

The point about it being a future classic is a fair comment, had I of done it I wouldn't of done much that couldn't of been returned to standard at a later date, that said fixings and pipework in the tank area would of required holes in the floor which isn't anything you can cover.

Modern LPG systems are very advanced so I wouldn't expect any hp loss, I can't say in the 4 years of working in the indusrty I have converted any and noticed the car being any slower, there are some very good systems out there these days, there are others that aren't, the installation and more importantly setup/mapping is the key to a good LPG fuelled car

[Le S2 Audi]

So you reckon that there is no power loss in an LPG conversion.... I guess things have moved along way from the early conversions then - as I know a guy who had a Chrysler GV converted and it was a total dog!!

But if you want better fuel effic.. etc What about an oil burner rather than spoiling an S2...

I am no doubting what you say, as I know naff all about them, and I am a total pleb when it comes to being a mechanic.

Give me a car to drive and then it a different matter...

[Jonnybravo]

If there is its minimal, old single point systems weren't great, some of the first and cheaper types of multi point systems again weren't any good and would not work well with certain vehicles. The systems I did fit were IMO the best available, with a mappable lpg ecu on board you could make hp gains, the thing is that isn't what people want with LPG, they want the same car and performance but it costing them less to run.



At the time of buying the S2 I didn't really look at it like that, I wanted the car I own, had seen it around and when it was up for sale I couldn't really resist it although I wasn't exactly loaded and I do have other projects so the idea was to have the Audi on LPG so I could get reasonable economy from it meaning I could enjoy it.