Is LPG OK for 1UZ?

[lowrnr]

Im looking at setting up a gas system to similar specs as kpwemu dont want huge hp at the moment just a cruiser but am putting into carby 2wd hilux and not sure what sort of fuel system to setup. Was gonna put fuel cell in the back but if i go gas instead not sure what pumps etc to upgrade. any help appreciated..... Anthony

 

[1uzvl]

I thought the reason for more timing on gas was it burns slower than petrol or is that wrong?

 

[Pro]

gas has a higher RON rating (102 or 106) versus petrol (generally 91-95).

more octane means it burns slower and more complete, so if you advance your timing you aim to get maximum expansion at maximum squish which equals maximum power and torque.

 

[deankdx]

after running My car around with My driving style, i managed to use 14L per 100km of premium at $1.29 so 100km=$18 not cheap for 500km week daily driver, so mine WILL be converted to duel fuel with a Gas Research S-480 mixer after i get engineers,
the gas fitter says i should not lose any power on gas, we will soon see.

 

[lowrnr]

So after all that what sort of fuel system should i be looking at setting up cause i didnt get the answer i was after in those responses. Not sure about what sort of fuel pumps etc or do i wait and find a gas system that works on a 5L or something similar and do without fuel all together... Carby mixer setup or gas injection ???????

 

[deankdx]

So after all that what sort of fuel system should i be looking at setting up cause i didnt get the answer i was after in those responses. Not sure about what sort of fuel pumps etc or do i wait and find a gas system that works on a 5L or something similar and do without fuel all together... Carby mixer setup or gas injection ???????

if you want straight gas, you wond need a fuel pump. what Kevin(kmpwu) had was an Impco 425 on his 302 ford motor. i am pretty sure these could be addapted to EFI, they feed a 351 clevo to low 14 sec quarter mile so would be about right for a 1UZ i think, they would be a bit ugly i would imagine?

the GRA(gas research australia) carb is a throttle body setup, rip off the factory throttle body, fit a TPS to the GRA carby run gas to it and a Lpg trimmimng computer running off the O2 sensors and off you go i am told?

duel fuel in a similar configuration only requires the other junk to remain like injectors etc, throttle body of GRA will be still used while in petrol, S-480 is the size i was recommended,
fuel pump wise, i would think most larger car EFI pumps would be fine, like an external falcon wagon pump etc. still require a lift pump and surge tank

 

[lowrnr]

Thanks for your help will have to track down a few parts and do some more research. Not sure if there is any people on sunny coast to ask but will find out...

 

[Pro]

the yellow pages will show a few up.

aftermarket LPG injection is pretty commonplace now.

 

[cribbj]

I have an Internet buddy in Oz who has tried one of the best propane injection systems available on his Bimmer with supercharged SR20DE Nissan swap. Due to problems with the high butane content in the propane there in Oz, he had to abandon injection and go back to a carby setup. His project diary is here: http://zymo.homemail.com.au/bmw2.htm and here's a clip out of it where he discovered the fundamental problem:

"Next major issue was the injection setup. I know from experience that the tank pressure drops very low in the winter time here in Canberra. Leave the car out and the tank could easily get close to 0degC. Or at least between 0 and 5degC. On a sweltering day when it was 40degC in the shed I measured the pressure. A mere 85psi! Uh oh....I decanted some liquid LPG from the car tank into a 4.5KG BBQ cylinder and popped it into the fridge for a few hours. Result was 28psi. Now there goes the injection idea. Reason being that the base LPG fuel rail pressure is 30psi with one psi extra per psi of boost. So this would make it 45psi under 15psi boost. You can see the problem here straight away. I would need at least 70psi in the fuel tank to feed the fuel rail system. The problem here is that LPG in Australia contains mostly butane which has a very low vapor pressure. I think from the charts I have looked at that at zero degrees celcius, the pressure is only about 10psi. So, I went back to thoughts of a GRA carby again."

 

[shinny]

For anyone still interested in this thread, here's something I've played with recently, and intend to continue playing with several more like it:

It's a UCF10 Celsior running straight gas injection (no petrol), with the stock ECU and wiring still in place, and a little extra help so that the timing and fuel can both be separately altered. Compared to the standard car, on LPG it makes almost 30% more power, with the only other change being a full exhaust system.

It hasn't been running long enough to be able to measure any VSR issues, but it is something I'll be keeping an eye on - not that I believe it's going to be a problem.

I've also got several other UZ (and other) LPG projects on the go at the moment.

 

[cribbj]

Shinny, let's hear more. How are the Prins/Keihin injectors working out for you? Since they're P&H injectors, how do they like being driven by the stock ECU?

I have a complete Prins system now with dual converters, and am debating which project should be the victim. I have a FI project going with the 1UZ, and an NA project going with a V12. I think the NA motor would be the safer bet to avoid any low temperature, low pressure LPG issues, although freezing weather is not one of our common problems in Houston.....

John

 

[edz]

GRA, Impco 425, dual fuel etc

add missing info

the GRA(gas research australia) carb is a throttle body setup, rip off the factory throttle body, fit a TPS to the GRA carby run gas to it and a Lpg trimmimng computer running off the O2 sensors and off you go i am told?

duel fuel in a similar configuration only requires the other junk to remain like injectors etc, throttle body of GRA will be still used while in petrol, S-480 is the size i was recommended,

GRA has some useful info - http://www.gasresearch.com.au/, they provide a neat tuneable throttle body arangement ($700), my gas guy doesn't like them as they are fiddly to tune, you have to change jets like a carby.

The 465 impco (looks like a 4 barrel holley $250-$400 approx) etc are simpler (but not as powerful - flow-wise) and can be adjusted by turning a screw. You can also get other sizes and shapes, I am using a pair of Impco 225's and twin turbo which should flow around 250hp ea. Have included some pics, Impco 225cfm (similar to 300) - Barrel with hole, Impco 425cfm - like a 4 barrel holley, GRA dual throttle bodies, twin GRA on a supercharged 308 etc. The turbo setups blow through an intercooler, through the mixer into the throttle body (with the impco), so if you get a backfire you only lose the turbo, not the intercooler as well!

My personal experience from driving a non-turbo car I had converted, dual fuel (LPG and petrol) knocks off the bottom end torque by 10-20%. You also need to be aware that lpg can backfire if not setup with a top quality ignition system (have driven taxis that were undrivable on lpg, yet ran fine on petrol when the ignition system was old). If you run dual fuel, you need to run petrol for around 40kms for every tank of lpg otherwise the injectors will clog and dry up and it will not run on fuel after a while. At 60c a litre instead of $1.40 I'll try lpg!

Hope this helps.

 

[deankdx]

For anyone still interested in this thread, here's something I've played with recently, and intend to continue playing with several more like it:
It's a UCF10 Celsior running straight gas injection (no petrol), with the stock ECU and wiring still in place, and a little extra help so that the timing and fuel can both be separately altered. Compared to the standard car, on LPG it makes almost 30% more power, with the only other change being a full exhaust system.

It hasn't been running long enough to be able to measure any VSR issues, but it is something I'll be keeping an eye on - not that I believe it's going to be a problem.

I've also got several other UZ (and other) LPG projects on the go at the moment.

cool, being in Vic also(Geelong) i'd love to hear more about it. like cost especially?
i have all the bits for mine exept a Gas research throttle body though. so might be easier to do that? B2 converter i already have. still like the duel fuel setup though

 

[Cobber]

Shinny,

Looks like a good set up you have there. The way the fuel price is going I think you will create some interest and be on a winner.
The help with timing and fuel? Is this done with a piggy back?

What size are the injectors? and would they be ok with a supercharger (7psi)?

 

[cyberdiamond]

I used to daily drive a straight gas worked 250ci 6cyl (5 speed) that ran an Impco 425 mixer on a 4 barrel manifold that was quite quick (13.2 sec quater).

I have a protoype lpg computer that injects the liquid lpg into petrol injectors.
The biggest advantage with injecting it as a liquid is the cooling properties it gives to the intake charge are huge!

It has run on a kit car cobra, I won't be using it on my UZ but it will be going into my 460ci F350 4x4 which should be fun! :veryhappy

 

[Cobber]

Cyberdiamond,

Interesting, tell me more.
This would be perfect for my supercharged set up.

What pressure are you running the fuel system?

Does the ECU adjust the tune based on the exhaust gas?

Why does that sound too easy?

I haven't made my fuel tank yet, it may end up being a cylinder. . . .

 

[cyberdiamond]

I can't remember the line pressure it was running but it does run an efi conventional fuel pump inside of the gas cylinder to keep the pressure up to a standard level.

The computer has a hand controller to ajust all the settings, I also can't remember if this one has closed loop or not but I think it has.

 

[shinny]

I'm still waiting on pricing information for parts - what I have used so far has cost too much, because I bought them from overseas and had to pay far too much tax... Largely due to suppliers in this country being, er, unhelpful - to put it nicely.

As far as controlling things, I am using an ECU that is trigger from the factory ECU, but has it's own injector drivers to cope with the demands of the LPG injectors. This also allows the fuel to be adjusted, and unlike any other LPG ECU I have seen, allows timing to be altered separately as well. I'll try to get a scan/photo of a dyno printout comparing before and after ASAP.

 

[cribbj]

As far as controlling things, I am using an ECU that is trigger from the factory ECU, but has it's own injector drivers to cope with the demands of the LPG injectors. This also allows the fuel to be adjusted, and unlike any other LPG ECU I have seen, allows timing to be altered separately as well. I'll try to get a scan/photo of a dyno printout comparing before and after ASAP.

Ah, OK, that answers that; I thought perhaps you were running the Keihin injectors directly from your OEM ECU, or through a P&H driver box.

I also have the Prins ECU, and debated whether to buy it or just use a P&H driver box like this: http://www.aempower.com/product_ems.asp (scroll about halfway down the page)

Very interested to hear more and see dyno sheets.

 

[shinny]

No, I'm NOT using the Prins ECU... Using a P+H box on the factory ECU would result in some pretty messed up mixtures, with no possibility to change the fuel curve either, let alone ignition timing.