LPG injection systems - Looks interesting!

[pundit]

As I'm spending $5k AUD ($4k USD) per year (at current prices) on fuel, I'm beginning to seriously consider switching over to LPG (Liquified Petroleum Gas). Of course the catch is while LPG is around one third of the cost of petrol (gasoline for our Yankee friends ;) ) it generally comes with around a 10-20% power loss and a 15-30% decrease in fuel efficiency (MPG). However although LPG has a slightly lower heat value than petrol, LPG is a very high octane fuel and can take advantage of both high compression ratios (12:1 or higher) and/or increased ignition timing advance.

Traditional 'old' technology LPG systems have often literally dumped gas into the inlet manifold in a not very well metered fashion with manifold backfires being a common and often damaging consequence. Newer LPG injection systems are now appearing on the market (SGI Sequential Gas Injection) utilising special injectors designed for LPG. While most of these systems require custom fuel delivery electronics a new system (GTI Stealth (http://www.gas-injection.com/lpg-gas-injection-technologies.html)) is able to be adapted to utilise the vehicles factory ECU and engine managment system to directly control the LPG injectors. To me, this looks interesting as it allows the existing vehicle electronics to be maintained and as the LPG delivery is better managed it offers improvements in both power and economy over conventional LPG systems.

Has anyone here had any experience with LPG injection systems?

Hmmm... how about a Megasquirted, turboed LPG install!? ;)

[rob101]

how many kilometers are you doing a year? and what is your average fuel consumption. Realistically how much longer are you going to keep your current car?
If you haven't thought about any of this yet i urge you to think about it.

LPG systems aren't financially what they seem for example say you're using an average of 14L/100 km on petrol so that means 18.2L/100 km of LPG up here fuel is 50c/L for LPG and $1.25/L (when you buy on tuesday as this is always when you get the lowest price) and an average distance per year of 25 000 km (fairly usual) i would expect that kind of installation to be $3000 at least. you're going to be driving for one and a half years before you break even. and if you think thats bad remember LPG will have excise on it after mid 2008 (i here (http://www.abc.net.au/pm/content/2003/s1011376.htm)). I would price a typical installation of LPG injection, i would expect my 3000 estimate is on the low side (thats about what it costs to do a mixer ring type setup on a 4wd). not to mention the limited availability of LPG outside the cities.

so...... i don't really know if its worth it really. Just buy your fuel on tuesday unlike the great myopic hordes who buy it late in the week and pay an extra 15c/L (last week i bought 98 octane on tuesday afternoon for 5 c less than price of 91 octane the next afternoon)

anyway gas research has a good website (http://www.gasresearch.com.au/) I don't want to dissuade you as I too would like to play with LPG. But there are certain financial realities one must face when examining LPG conversions.

[Paul in NZ]

how about the fact that at some time petrol will be even MORE expensive.Will LPG track the price of petrol?

[rob101]

how about the fact that at some time petrol will be even MORE expensive.Will LPG track the price of petrol?
yes because the demand for LPG is likely to rise around the world. and thus our own prices, as our market for LPG is deregulated as with petrol. I am not sure that the price of petrol will rise that much. it is interesting to note that the previous 70c/L situation was well below where it should have been if you look at inflation. and we aren't yet at the price levels that the oil crisis bought about.
but...... people have to whinge about something right?

[pundit]

how many kilometers are you doing a year? and what is your average fuel consumption. Realistically how much longer are you going to keep your current car?
If you haven't thought about any of this yet i urge you to think about it.

LPG systems aren't financially what they seem for example say you're using an average of 14L/100 km on petrol so that means 18.2L/100 km of LPG up here fuel is 50c/L for LPG and $1.25/L (when you buy on tuesday as this is always when you get the lowest price) and an average distance per year of 25 000 km (fairly usual) i would expect that kind of installation to be $3000 at least. you're going to be driving for one and a half years before you break even. and if you think thats bad remember LPG will have excise on it after mid 2008 (i here (http://www.abc.net.au/pm/content/2003/s1011376.htm)). I would price a typical installation of LPG injection, i would expect my 3000 estimate is on the low side (thats about what it costs to do a mixer ring type setup on a 4wd). not to mention the limited availability of LPG outside the cities.

so...... i don't really know if its worth it really. Just buy your fuel on tuesday unlike the great myopic hordes who buy it late in the week and pay an extra 15c/L (last week i bought 98 octane on tuesday afternoon for 5 c less than price of 91 octane the next afternoon)

anyway gas research has a good website (http://www.gasresearch.com.au/) I don't want to dissuade you as I too would like to play with LPG. But there are certain financial realities one must face when examining LPG conversions.

Excise on LPG has been deferred until 2011... and will be progressively phased in @ 2.5 cents per year over five years until reaching a maximum excise of 12.5 cents per litre.... Cough, cough... "Mother should I trust the Government?"

http://www.esanda.com/common/pdfs/Fleetview12.pdf

I currently clock around 30,000kms per year @ an average of 14.5 litres per 100kms. The newer SGI (Sequential Gas Injection) systems are more efficient than the old systems. My recoup period would be approximately 12-14months based on a saving of $3,000.00 per annum (I'm EAT chipped and running premium unleaded @ around $1.40-$1.55 per litre) LPG down here fluctates between 40-60 cents per litre. Yes LPG will increase in price as demand goes up, but even taking all other factors into consideration (installation costs etc) LPG will still be a cheaper alternative for the next ten years after which none of us will be able to afford to drive any vehicle powered by non-renewable fossil fuels! :(

[rob101]

yeah, well get a quote of how much an install will cost. I think everyone on this board will be interested (myself included). I seriously think 3000 will be too little, but..... i simply just don't know, but assuming that this costs more than the mixer ring installs it going to be at least that much.
Oh they pushed the excise back thank god, from an environmental POV the sooner lots of people start using LPG the better. the difference in emissions is huge from what i've read. They already have a rebate on new LPG vehicles i believe.
personally i am going to probably get a new car in a couple of years (big boy will be at 300 000 km then;) )so for me its not really worth it

[Paul in NZ]

will you run a lpg tank in the boot pundit?

[pundit]

will you run a lpg tank in the boot pundit?
I'm not sure. If I go ahead with something like the GTI system I'll probably ditch the fuel tank altogether and just run external LPG tanks in place of the original.

Some of the new LPG injection systems can start on LPG from well below zero degrees so the need to use petrol for cold starting is no longer an issue.

I must admit, I'm not too fond of LPG tanks in the boot (er trunk) the or inside the passenger compartment as in some station wagons.

Just think, you could run a 12:1 compression ratio and with something like Megasquirt fine tune the system for the best efficiency.
With a properly setup system low end torque may even better than petrol.

[genphreak]

ECU, LPG and a SNAIL may be a good way to go?

[rob101]

ECU, LPG and a SNAIL may be a good way to go?
somehow i think that would defeat the purpose of saving money!
It'd be interesting to crunch the numbers of buying a corolla or matiz or echo for during the week AND having a e34 but only driving the e34 on select occasions.
either that or just buy a 750iL and run it on LPG
i think that would pay itself off in about half a year:p

[Morgenster]

Just think, you could run a 12:1 compression ratio and with something like Megasquirt fine tune the system for the best efficiency.
With a properly setup system low end torque may even better than petrol.

The latest liquid injection systems already achieve this without major engine block changes. Those are injectors that spray the LPG liquid instead of gaseous and the expansion ratio is some 400:1 -> while the LPG goes in the cylinder it expands and ups the pressure while lowering the temperature at the same time. Preliminary tests with these systems have shown better lower end torque on engines without modifying anything but the injection system.

[BillionPa]

LPG + turbo = boom.

but anyway, i did consider it, but only if i managed to find a broken E38 with a 3.5L V8 M62, and put in 12:1 or higher compression pistons.

the other aspect is that gasoline has lots of lubrication for the cylinder walls that LPG doesnt, so i would still use my gas tank, but hook it to a single fuel injector in front of the intake manifold to squirt a lubricative high octane substance (50/50 acetone/FP60) in vapor form, which would increase power as well in a higher compression engine with timing closer to TDC.

and using individual cylinder propane injection with special bosch injectors is the only way to go.

[Morgenster]

LPG + turbo = boom.



No, not really. I know a few that have been driving turbos on LPG without a single problem.
Besides, with a sequential injection system there'd be zero risk for that.

[Ausmpower]

There used to be an LPG injected supercharged 351 in an old ford capri running at the drags here in Western Australia.......It used special injectors and a Microtech LTX-8 ecu.

She was pulling 850 HP on the Dyno....and running mid 8's on slicks.

They had to use magneto ignition as the cylinder charge density was 'blowing the flame out' with MSD.

[F4Phantom]

I just heard on the radio that the Aussie government is going to offer something like 1k to convert you car to LPG. Sounds good to me.

http://www.abc.net.au/news/newsitems/200608/s1713855.htm

[rob101]

I just heard on the radio that the Aussie government is going to offer something like 1k to convert you car to LPG. Sounds good to me.

http://www.abc.net.au/news/newsitems/200608/s1713855.htm
that rumor has been around for a while, but we'll see what happens
i think it would be a good idea. but most good ideas don't happen!

[Paul in NZ]

a straight 1000 gift or an interest free loan?

[Ausmpower]

It's actually a $1000 dollar rebate on the cost of the installation of the gas system.

it is in place already here in W.A.

I've been told by a gas fitter that I cannot fit gas to my 535 due to the type of management system fitted to my car (stock) and that if it ever back fires the AFM vane will shatter when the backfire slams it shut.

[Michael999]

Past day on the radio its been announced several times that the rebate is "up to $2000".

Im guessing that to get the maximum you would need to purchase a brand new car.

I doubt that the government is going to give out $2000 for any car that wants it, it would cost them too much, it will likely be ab encouragement to purchase a new car, which they WILL make that $2000 back on in tax.
Guy who did our volvo gas conversions charged us $1500.

[genphreak]

I just saw our lying cane toad of a prime minister hop out of the swamp to chirp about it on TV.

Trying to gain support from this relic of an idea on the news, he revealed that they have no idea about how the criteria will be set and have budgeted to do '2-300 hundred thousand cars' (he said under his breath). You can bet their mates will be keen to make their fleets the main beneficiaries.

OK, sorry: That was a bit cynical of me.

Perhaps if we read between the lines a bit more, given the numbers they are hoping to limit it to, perhaps we can expect the rules to be something like the following:

To get it you will have to meet these criteria:
You must book your car in for conversion RIGHT NOW or buy a new one RIGHT NOW with LPG optioned. If you wait until the details are released so you know how much you can count on (if anything), you won't be eligable. Or;
You must be in a country location (where gas stations don't stock LPG). If you are one of these people you may have a month to think about whether you will take up the offer. Or;
You must be in a marginal country electorate, have a family and an annual income of more than $150,000 a year (or they might just mandate that you must buy, or have bought in the last 3 years, a new car).This, (or owning a corporate fleet or two) will give you the best chance of cashing in.

Realities aside, I think it will be interesting to see how they stop the cabbies getting it. There are always a few hundred thousand cabs that need replacement since they can never bring themselves to maintain them properly...

[Morgenster]

It's actually a $1000 dollar rebate on the cost of the installation of the gas system.

it is in place already here in W.A.

I've been told by a gas fitter that I cannot fit gas to my 535 due to the type of management system fitted to my car (stock) and that if it ever back fires the AFM vane will shatter when the backfire slams it shut.

Odd, there's solutions to that as well. Backfire doesn't really occur unless your valves don't shut properly or you have charcoal in your cylinders. If all else fails there's always an extra 'backfire valve' that can be installed between the intake manifold and the throttle housing. Lots of Dutch cars have those.

Anyway I've seen many M30's equipped with an LPG aspiration system. They work fine.

[Ausmpower]

Odd, there's solutions to that as well. Backfire doesn't really occur unless your valves don't shut properly or you have charcoal in your cylinders. If all else fails there's always an extra 'backfire valve' that can be installed between the intake manifold and the throttle housing. Lots of Dutch cars have those.

Anyway I've seen many M30's equipped with an LPG aspiration system. They work fine.

What system are they running?

Australia relies on draw through single metering gas systems (Impco) as they are the most common and one of only a few ADR (Australian Design Rule) approved systems.

Does your m50 start on pertol or is it gas only?

Gas systems can backfire when starting cold, not due to valves not closing, but the slow combustion of over rich gas/air mixtures burning back into the manifold.

Ford and Holden 6 cylinders from 96-2003 here were renown for blowing the airfilter boxes apart if they fart when cranking.......And they're factory systems!:D

[skr]

come on people, everybody likes LPG??? Those prices must have realy scared you. I've been paying 1.2 $ for diesel for some time now, gas is like 1.4 but i'd never consider it. big ugly tank in the trunk+ringing it at much fewer km doesn't realy sound good... Maybe it's just a national thing but around here car passionates hate lpg

[BillionPa]

or you could run gas/lpg in 66/34 ratio, you would spend less on fuel and not need as big a propane tank. and I think there is some optimal ratio that gives a good increase in power, but thats probably not it.

[Morgenster]

What system are they running?

Australia relies on draw through single metering gas systems (Impco) as they are the most common and one of only a few ADR (Australian Design Rule) approved systems.

Does your m50 start on pertol or is it gas only?

Gas systems can backfire when starting cold, not due to valves not closing, but the slow combustion of over rich gas/air mixtures burning back into the manifold.

Ford and Holden 6 cylinders from 96-2003 here were renown for blowing the airfilter boxes apart if they fart when cranking.......And they're factory systems!:D

Well that's something you don't get to choose here. There's no way any singlepoint system will let you start the car without hassle. Especially in winter because the vapouriser would just freeze up. Technically, an LPI system will let you do it, but the only safe system for starting on LPG is liquid injection which is patented by a single company and needs a big push in marketing.
Starting on a singlepoint LPG system will flood your manifold with LPG gas for the time you're cranking and that's a surefire way to get into trouble.

I run a singlepoint system but always start on petrol, let it warm to center mark and then switch to LPG. It won't switch (automatically) before hitting 3000+ rpm. After that you can let it idle of course.

I have an LPG tank of some 70L in the spare wheel well that lasts me 400-500 km before refuelling.

As far as financial benefits go: 1.48 euro is the pricepoint for premium petrol fuel here. LPG is at 0.43 euro. Do the maths considering I drive 3000 km a month.

Edit: The M30 engines I've seen use the same type of system I use.