2JZ-GE with LPG Gas idea?

[ivandude]

Hey guys,

I'm curious as to whether this will work, has anyone done it and if a viable idea - to install an LPG system onto the 2JZ-GE.

I like the Supra, don't care about the boot space as there is none and could probably go for a donut design tank / semi space saving to leave some room, basically cheaper to run the car around is the main idea though and still enjoying the good old JZA80. Despite not holding onto any 1 car for longer than 9 months, I really would want to settle with this 2JZ-GE powered vehicle as they are so well rounded IMO in a sturdy and safe vehicle that just works and is "bulletproof", I have no complaints on the JZA80 besides its Premium 98 fill-ups of 62L $100 these days, so I would really look to do this if things looked well for the idea.

I want a daily car that has some power but not chewing heaps of fuel if I keep it for years to come. I'm happy with a N/A Auto Supra for its looks/handle/power. The other choice is some smaller cars (4AGE Levin Coupe, Corolla VVT-i, something plain, dare say a Honda Integra) but most choices arent too powerful or as appealing, although one choice can be a 1JZ-Chaser but I know the fuel consumption is the same / expensive so I'd end up look at putting that on gas as well for long-term use. Being a turbo car I would think it needs even more custom work than a non-turbo. So yeah, non-turbo seems easier to LPG up and might as well look into doing it to this car if it means keeping it for longer than planned.

Im looking for opinions on anything about this possible idea:
- Costs, proper mechanic/experience tips, custom things to look into, experience running this or knowing anyone who has, power drop/increase, and so forth.
I don't know where to begin and searching the net for past few weeks on this topic hasn't been to eventful, thanks Toymods

[Radar]

Gasresearch carbs Check it. Then Im pretty sure its just a case of standalone electronic timing control.

[andrew_mx83]

i run my current daily cressida and the 2 before it on dedicated lpg and i LOVE it. setup right you wont lose any power as well as having a cleaner motor and half the fuel costs. i do about 15lt/100km out of a stockish 7m-ge on gas @ $0.50/lt. you can either leave the stock ecu to run spark and wind the dizzy round a bit or go aftermarket ignition but there is a bit of work in this. im currently reco'ing a head which will give me a CR of 11.5:1, cant wait to see how it goes!

gasresearch is great for boost but no so much for NA. i use impco gear religiously and im stoked how good it is. very simple to tune, gives great low end driveability and can be setup for closed loop mixture control.
dual fuel is generally a waste of time IMO. go dedicated gas and use the space where the petrol tank was for an LPG donut or conformable tank, delete fuel rail and associated hardware from the engine bay for more room to work on stuff and a nicer looking engine

[ivandude]

Nice! I have thought about 7M-GE LPG Cressy's as an option to buy already all going, seem to pop up once every 6 months in NSW.
That info is good to know, dedicated gas is something I wasn't aware of & deleting all the other fuel tank etc taking up space.

By those calculations andrew sounds like an average of 300-350km per full tank 50L @ $25 each fill. That is about a third of the cost I currently use then

Thanks a lot for the info, I am getting some replies from Supraforums members to see what they have thoughts on. I dont think the 2JZ can be can be advanced on the timing as simply as the older motors, so ignition upgrades probably needed.

[andrew_mx83]

300-350km per full tank 50L @ $25 each fill

yep, or about 700 when i had twin tanks

2jzge runs a dizzy doesnt it? then just back off the bolt and wind it round some.... easy

[CELICASUPRA7M]

doubt there would be anywhere to mount a lpg tank in a jza80.
You have to remember your driving a performance car, plus its auto. put your foot down and it will use fuel.
does it really need 98 octane fuel?

[andrew_mx83]

About Conformable Tanks*-*Propane Performance Industries Development Technolgy Systems -Cutting Edge Technology in Propane Gas Tanks

[Sam_Q]

andrew how does the impco compare to the gas research?

[andrew_mx83]

to make a nice easy comparison, think of GRA as a weber carby, an open choke type of system. the impco gear is more like an SU carby or constant depression type.
impco mixers use a diaphragm to control the fuel mixture which helps keep the air speed up under low vac conditions so when you snap the throttle open at low rpm the engine doesnt bog down.
tuning impco is a piece of cake -the big nut controls WOT mixture and the small screw controls idle/light throttle mixture. cruise mixture is set by the shape of the diaphragm, which are available in a few different types. i use the feedback diaphragm/mixers which are basically set to run pig rich, then theres a lil electronics box that takes a signal off the o2 sensor and bleeds air in at the converter to lean the mixture out accordingly to maintain stoich.

tuning GRA is a bit more difficult from what i understand, there are jets and metering rods etc rather than simple screw adjustments. most boosted applications choose GRA, and the general thinking is that the impco setup is more suited to NA.

[2jace]

go to southeastlpg.com.au

[Hurricane]

im not exspert but this is what ive seen/played with

i run GRA in my 308 in my FJ60
it works great, my old man has impco (not sure what model) and it doesnt work as well, its cheaper to setup and is easyer to turn though.

GRA throttle body is much like a carby, its has idle and cruise jets, fine adjustments made with a metering screw and corse with new jets.
then the main metering jet moves back with more throttle alowing more gas passed to the main jet.

then to adjust the mixs at any throttle positon, u buy a new meter needle, or lathe up your own, the smaller the needle at a given depth adds more gas.

so its much like swaping jet in a carby in a way. or changing the tapper in a su or motor bike main jet.

i beleave that you cant blow though boost pressure useing a impco because of the diaphram setup?

all my mates that had LPG turbo cars ran GRA with good results and one of my mates that stuffed around got really good power and fuel milage from his 4.2 patrol.

i bealeave the impco setup would be cheaper to setup.

another option in LPG injectors, its not a cheap but there has been some really good results from it.

guy at work has it on his BA v8.
its piggy backs of the stock ecu, useing there mags as base maps and the ignition setup.
then the LPG has its own ECU that u can retune the gas just like any petrol setup.

he makes the same power (with in 10kw or something) and gets more KM'S per 100 than the fuel but it costs half the price or less even.

i think in total it cost him 5k for every thing fitted and tuned, goin from a stock BA petrol. then with the gas rebate it was even less.

it been running with out any major faults (minor fine tunning issues) for 1 - 2 years now.

said its hte best thing hes ever done.

[convertableTA23]

From the few gas cars i have seen in at work, injection is definatly the best way to go, expensive to set up, but more power and better economy. The way i see it is mixers are like carbies, old school, effective and cheap, injectors are just the same as fuel injectors, modern, even more effective but not so cheap. Ask yourself this, would i replace a efi setup with a carbie????? Just my 2 cents

Plus, straight gas systems are really clean burning, ever wondered why those straight gas taxis can do 800,000Km without proper servicing?????

[Hurricane]

im lead to beleave that the LPG doesnt comtaminate the engine oil as much as petrol, so that might help with longer service life? though i dont let my oil changes go any longer that normal, but every time i drain it, it still looks not to old and much the same colour as when its new. compaired to my petrol cars.

another good note for the GRA setup i run, its never backfired ever! that seems to be the biggest issue ive seen with many cheaper LPG setups (though there mainly dual fuel)

my pick would be LPG injection, ether vapour or liquid if you have the cash.
then GRA throttle body.
then IMPCO setup.

they seems to be the best that ive seen/played with over the years.

dan.

[convertableTA23]

That's it, lpg burns much cleaner, although at a higher temperature, which is why the oil stays cleaner. However it does require cooler plugs and can burn out exhaust valves prematurely.....

[Radar]

DanSpec - LPG Vapour Injection Megasquirt 400m

Was told My AutronicSMC could also run the injectors, so id hazard a guess that most aftermarket ECU's with low-ohm injector outputs can run these injectors.