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lpg conversion anyone ??
Posted: Wed Oct 10, 2007 10:23 am
by bazza93
see this on ebay
http://cgi.ebay.co.uk/BMW-320i-LPG-CONV ... dZViewItem
is this a first ?

never seen this on an e30
is it something worth doing, is there any power gain-loss ?
Posted: Wed Oct 10, 2007 11:26 am
by StuBeeDoo
Nowhere near a first!
Brianmoooore's done it (years ago).
There's a lad with a white 318iS (2.1 engine IIRC!) done it.
.....And I've done it.
There may be others here who have too, but I'm old and my memory's failing.
It's well worth doing. I bought a brand new system and DIY'd it. Cost me under £750 and in 3000 miles I calculate I've saved over £250 already. If you get the necessary stuff off eBay, you could do it for a couple of hundred sovs.
I can't tell any difference in the performance, but then I'm not a experienced race driver. 
Like most (all??) people who convert to LPG, I wish I'd seen the light years ago.
Re:
Posted: Wed Oct 10, 2007 11:41 am
by Car-Nut
mate at work has done it on an an e39 535 says he fils up for about £15......
He paid £1500 quid though for the conversion

Re:
Posted: Wed Oct 10, 2007 11:43 am
by bazza93
fills up for £15

my e30 used to cost £45

my pajero costs..........................................£75

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Posted: Wed Oct 10, 2007 11:54 am
by daimlerman
I have pondered this for a while now.PPC ran an article a while back talking about LPG as a performance fuel.Now aftermarket ECU's are available with switchable MAP's I am wondering if it would be possible to have a MAP best suited to LPG and one best suited to petrol,so that one can start up on petrol and switch to LPG on a hot engine.I have little understanding of how this might work,though,or the costs involved.My only experience of LPG was with a 1.4 Renault that I had converted proffesionaly at a cost of (I think) around £1500.I covered some 60,000 miles in this car in ten months at an average LPG consumtion of 31mpg.On unleaded,I was returning 36mpg.I noted a small performance drop on LPG.
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Posted: Wed Oct 10, 2007 11:57 am
by bazza93
daimlerman wrote:I have pondered this for a while now.PPC ran an article a while back talking about LPG as a performance fuel.Now aftermarket ECU's are available with switchable MAP's I am wondering if it would be possible to have a MAP best suited to LPG and one best suited to petrol,so that one can start up on petrol and switch to LPG on a hot engine.I have little understanding of how this might work,though,or the costs involved.My only experience of LPG was with a 1.4 Renault that I had converted proffesionaly at a cost of (I think) around £1500.I covered some 60,000 miles in this car in ten months at an average LPG consumtion of 31mpg.On unleaded,I was returning 36mpg.I noted a small performance drop on LPG.
just as i thought, you do get a performance loss then

Re:
Posted: Wed Oct 10, 2007 12:01 pm
by StuBeeDoo
bazza93 wrote:fills up for £15

my e30 used to cost £45

my pajero costs..........................................£75

I did a cost comparison (in May this year) before fitting the LPG, and my 320i Touring was costing me over 17p/mile in normal unleaded.
Over 3000 miles, LPG has cost me under 9p/mile.
I usually put in £10 of petrol a month for starting/cold running, but I haven't yet had to use all of it - I've got more petrol in now than when I first switched to LPG.
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Posted: Wed Oct 10, 2007 12:06 pm
by bazza93
defo something to think about doing then !
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Posted: Wed Oct 10, 2007 12:12 pm
by daimlerman
I am told that the bigger the motor,the less you notice the performance loss.The guy who converted my car is a Jaguar specialist(I met him via the Daimler OC) and he claims that on a 5.3 V12 you notice no difference.On my low power,small engined French turd I was using more throttle to maintain the same speed.My feeling is that with a special MAP for LPG,it may be possible to overcome this.I was able to reduce running costs as stated byStuBeeDo,at the time I was working as a freelance courier and I was able to undercut my competitors who ran diesel engines.....
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Posted: Wed Oct 10, 2007 12:13 pm
by StuBeeDoo
bazza93 wrote:just as i thought, you do get a performance loss then

StuBeeDoo wrote:I can't tell any difference in the performance, but then I'm not a experienced race driver.
Obviously, it depends on how much power the car has to start with, and it will also depend on how well the LPG system is set-up. 1.4 Reanults aren't exactly powerful, are they?
Dual-map ECU's (MegaSquirt, Emerald) are more than possible with LPG. It's been done quite a few times. Theoretically, with an LPG-specific map, you should see some power gain running on LPG.
I've never had my Touring on rollers, but it's fitted with a 325i TB and a very wild chip. According to those (Andyboy for one) in the know, it should be making 140bhp on petrol. If that's reduced to (close to) the original 320i figure of 129bhp on LPG, I'd be very surprised.
In day-to-day driving, the difference in performance between the two fuels in my car is so negligable, it isn't noticable.
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Posted: Wed Oct 10, 2007 12:22 pm
by bazza93
so you should be able to still performance tune an engine that runs on lpg
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Posted: Wed Oct 10, 2007 12:26 pm
by StuBeeDoo
bazza93 wrote:so you should be able to still performance tune an engine that runs on lpg
Most certainly! IIRC, there's a Focus running 'round that's putting out 400+bhp on LPG.
..... And there's a thread on here with details of an ACSchnitzer E92 3-series fitted with a V10 putting out 552(IIRC)bhp on LPG.
Nothing to stop you Dude. You've nothing to lose and £Â£Ã‚£'s to save.
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Posted: Wed Oct 10, 2007 12:38 pm
by bazza93
552 bhp on lpg

what next............ F1 on lpg
Posted: Wed Oct 10, 2007 12:43 pm
by DRIFTBOY
This is good news for me!
I'm soon to start fitting my LPG kit to my M30 3.5 engine.
I'm doing it partly to save money and partly to see for myself what it's all about and to learn something new.
I can't wait!
I haven't heard anyone say anything negative about LPG so far either.
Re:
Posted: Wed Oct 10, 2007 12:45 pm
by bazza93
i think the only downside is where to get it

not many fuel outlets stock it !!!
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Posted: Wed Oct 10, 2007 12:51 pm
by daimlerman
Most BP forecourts have LPG,some Total,some Jet and the odd Morrisions store.It's like anything else,you soon get used to seeing it....oh yes,Shell have it on some sites as well.
Posted: Wed Oct 10, 2007 1:00 pm
by StuBeeDoo
IIRC, there are about 1300 listed sites in the UK at the moment.
Price varies more than petrol and diesel do though, and as with petrol and diesel, it depends a lot on the location and popularity of the site.
The cheapest currently seems to be 39.9p/ltr and I've seen reports of over 52p/ltr. Most I've ever actually paid so far is 47.9p/ltr (I was desperate!)
BP seem to have a policy that their LPG price is set at half the price of their standard unleaded for some reason best known to themselves, so I tend to avoid them as to me it seems to be blatent profiteering at the LPG user's expense.
My local Shell site is currently 94.5p unleaded and 42.9 LPG.
I usually get mine from my local Total outlet where it's 97.9 unleaded, 39.9 LPG.
Posted: Wed Oct 10, 2007 1:02 pm
by StuBeeDoo
Bazza, I'm guessing that there should be plenty of outlets in your area. Check this website out..... http://www.getlpg.org.uk/
Re:
Posted: Wed Oct 10, 2007 1:05 pm
by bazza93
so does this work with the turbo'd variety of e30's ie does it affect the turbo in any way ?
could you actually build an engine to solely run on lpg or has it got to be a petrol engine aswel ?
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Posted: Wed Oct 10, 2007 1:09 pm
by march109
I would assume because LPG burns 'cooler' than petrol that its actually better in turbo applications as it would not be so easy to cause detonation.
Turbo guru could confirm tho?!
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Posted: Wed Oct 10, 2007 1:11 pm
by klu99apm
I converted my 325 touring myself to LPG nearly 2 years ago. It was an easy enough job (especially with a few PM's to Brianmooore about the electrics!)
I bought a complete kit for about £500 with a Leonardo ECU control for the gas. I do notice a slight performance loss but not a lot, and if you feel the need max performance it can be switched over to petrol at the flick of a switch. I never seem to have a problem finding a petrol station with gas - you notice them more perhaps if you have an LPG powered car!
For me it means, as a student, I can afford to run a BMW 6 cylinder car while eveyone else is stuck with 1.4 clio's etc!
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Posted: Wed Oct 10, 2007 1:13 pm
by bazza93
march109 wrote:I would assume because LPG burns 'cooler' than petrol that its actually better in turbo applications as it would not be so easy to cause detonation.
Turbo guru could confirm tho?!
thats a well valid point

did'nt think of that
also must be the same for supercharging then
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Posted: Wed Oct 10, 2007 1:23 pm
by Steviec
klu99apm wrote:I converted my 325 touring myself to LPG nearly 2 years ago. It was an easy enough job (especially with a few PM's to Brianmooore about the electrics!)
I bought a complete kit for about £500 with a Leonardo ECU control for the gas. I do notice a slight performance loss but not a lot, and if you feel the need max performance it can be switched over to petrol at the flick of a switch. I never seem to have a problem finding a petrol station with gas - you notice them more perhaps if you have an LPG powered car!
For me it means, as a student, I can afford to run a BMW 6 cylinder car while eveyone else is stuck with 1.4 clio's etc!
Where did you get your kit from and would it be easy to install for a non mechanic?
Im very interested in doing the conversion myself, perhaps we could get a group buy going?
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Posted: Wed Oct 10, 2007 1:31 pm
by bazza93
perhaps someone could do a tech write up and put as a sticky !

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Posted: Wed Oct 10, 2007 1:54 pm
by march109
bazza93 wrote:march109 wrote:I would assume because LPG burns 'cooler' than petrol that its actually better in turbo applications as it would not be so easy to cause detonation.
Turbo guru could confirm tho?!
thats a well valid point

did'nt think of that
also must be the same for supercharging then
Very much so, take a look at the BP ultimate 102 octane thread running at the mo.
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Posted: Wed Oct 10, 2007 2:30 pm
by daimlerman
I am also interested,but would need a guide to follow.As I have already said,I would think that one of these multi MAP ECU's is the way forward so as to take proper advantage of LPG's higher octane rating.
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Posted: Wed Oct 10, 2007 3:04 pm
by ChrisBarns
LPG is cheaper because of the tax rate being much lower. Does anyone know how long this tax incentive will last? When it was first bought in there was a 5 year guarantee but that must have expired now?
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Posted: Wed Oct 10, 2007 3:06 pm
by march109
daimlerman wrote:I am also interested,but would need a guide to follow.As I have already said,I would think that one of these multi MAP ECU's is the way forward so as to take proper advantage of LPG's higher octane rating.
Only worry about the higher octane rating if you have a F.I or highly tuned engine.
I think the next big thing will be biofuel (diesel alternative), allready very cheap, and if you can't be bothered to filter your own it will allready be available from your local supermarket in the form of vegetable oil, all clean and refined allready at around 40p per litre.
Less popular at the moment is bioethanol (or bioethanol mix, the bio alternative to petrol) the bugatti veyron reputedly gains circa 30hp running on this stuff, and to think the Ford model T was the first biofuel car as it ran on ethanol because there wern't any garages round the corner and the science of refining fuel was in its infancy in 1908.
Look out for petrol pumps dispencing and cars run on petrol and bio ethonol mixes in 2008. Thee however will simply be 85% normal petrol to 15% ethonol (or approx).
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Posted: Wed Oct 10, 2007 3:14 pm
by bazza93
am i correct in saying you can't do this to a diesel ?
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Posted: Wed Oct 10, 2007 3:21 pm
by StuBeeDoo
bazza93 wrote:am i correct in saying you can't do this to a diesel ?
IIRC, LPGing a diesel is possible, but is a very precise science and no LPG kit manufacturer has really mastered it. Another IIRC - with a diesel, it still needs a proportion of diesel in the mixture, which is where the preciseness(sp?) of the science comes in. Too much diesel makes the LPG a waste of time. Too much LPG will screw the engine.
I may have got that all wrong though. I didn't pay too much attention as it was of no real interest to me.
If someone (Brian?) knows different, I'm sure they'll put me right.
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Posted: Wed Oct 10, 2007 3:23 pm
by bazza93
StuBeeDoo wrote:bazza93 wrote:am i correct in saying you can't do this to a diesel ?
IIRC, LPGing a diesel is possible, but is a very precise science and no LPG kit manufacturer has really mastered it. Another IIRC - with a diesel, it still needs a proportion of diesel in the mixture, which is where the preciseness(sp?) of the science comes in. Too much diesel makes the LPG a waste of time. Too much LPG will screw the engine.
I may have got that all wrong though. I didn't pay too much attention as it was of no real interest to me.
If someone (Brian?) knows different, I'm sure they'll put me right.
thats good enough for me

its a poss no no

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Posted: Wed Oct 10, 2007 3:24 pm
by march109
bazza93 wrote:am i correct in saying you can't do this to a diesel ?
yes you are correct (though I stand to be corrected on my resoning why..) I believe this is because LPG has a high octane rating meaning it takes more heat energy to ignite the fuel, diesel engines require not a low octane because diesel isn't measured in octane (measured in cetane) but an ability to autoignite under pressure and not heat application.
Diesel is required to have a property of autoignition (which is the opposite to petrol and lpg), as a diesel engine requires the fuel to be ignited partly by the compression stroke (by the compression), (and sometimes partly by the glow plugs and temperature of the engine). In diesel engines the glow plugs usually only start the engine and are not required for continual running.
However there are
some vehicles that use LPG in diesel engine applications I'm not sure how this works or what extra equipment is needed. But have read that it is mixed with the diesel instead of being used as the sole fuel as in spark ignition engines (petrol engines). Typially 10-20% lpg to fuel.
This is because LPG will not ignite under compression so the diesel acts as the accelerant to ignite the LPG, it is quite popular in big trucks in Australia where they travel long distances with heavy loads and LPG is much much cheaper in comparison to diesel as it is here.
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Posted: Wed Oct 10, 2007 3:24 pm
by ShakeyC
A good friend had lpg on his Ford ST race car few yr ago he had ful sequential lpg which safer, more economical and less power drop compare to old lpg kits. With lpg you need more lpg to air ratio which saps some power but ful seq helps instead of injectors pouring lpg into manifold its more direct so less danger to.
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Posted: Wed Oct 10, 2007 3:28 pm
by bazza93
sounds like there is a lot of techno still being done on lpg, perhaps this is going to be the fuel of the future
glad to hear that a few zoners are already dabbling with this idea

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Posted: Wed Oct 10, 2007 3:30 pm
by march109
LPG is going to die a death when the government tax it as they do with petrol or diesel.
at the moment it is heavily subsidised with tax incentives, it actually costs more to produce at this time than other fuels due to the nature of its supply and demand.