I've got gas! (LPG installation)

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ambaal

ambaal

10 Year 15 Year
Joined
Apr 23, 2008
Threads
14
Messages
42
Location
Sydney, NSW, Australia
Greetings, everyone.

I'm here to tell the tale of gas equipment installation.

Here, in australia, petrol prices are around 1.6$ for a litre of 95RON, which is about 1.6 US Dollar, and driving as much as I want with those prices make me think of things like poverty, starvation and bankruptcy.

Since I'm not a big fan of those things, a clever plan was devised: to visit magic dwarfes from the kingdom of LPG (liquified petrol gas) installation and get them to forge an LPG equipment for me.

This job took them one full business day and 3000$ AUD to perform.
The girl in question is 80 series '97 landcruiser, with auto tranny and 180k km on clocks.

The sub fuel tank was removed, and so was the spare wheel with its assembly, to give place for 115lt gas tank. Since gas tank cannot be filled past 80% (there is an automatic cut-off valve on it), it gave me 92lt of usable LPG fuel.

Fuel Tank
tank.jpg


In the engine bay, the evaporator (or whatever the name for that vile device is)
was installed on the LHS, connected with two hoses to cooling system - that thing convert gas from liquid to, well, gas by using engine heat.
Another addition there was a big shiny device put into intake manifold, which mixes air with gas, plus lots of wiring and even some lamps.

Engine Bay
engine.jpg


In fuel latch, my precious fuel cap holder was removed, and LPG fuel connector was added.

fuel.jpg


Inside i've got one extra switch on the lower central dash which selects type of fuel - petrol or LPG. Don't really see why not use existing one for sub-tank, probably will wire it myself later. Also, top console sub-tank meter was connected to LPG tank to show how much fuel is remaining there. Funnily enough, it is pretty accurate.

As I was explained, on cold starts (morning, etc) LPG systems, even when switched to gas, starts on petrol first, then switches to LPG after.

Installation came with 100.000km warranty and free tune-up after 1500km. Which happened in less than a week.

Power after installation was slightly reduced on petrol. Gas one feels about the same in city and flat highway driving, but in mountains dropped noticably on uphills. It turned out on 1500km inspection I was going a bit lean on LPG.

Аfter free service at 1500km it was remedied and the power is now very satisfying both petrol and LPG. Actually pulls a bit harder on LPG on low revs, probably - cannot tell for sure with bloody auto transmission. :)

The numbers for conversions are following (prices are AUD, which is very close to USD now):

Petrol consumption before install: 15-18 lt per 100km, 13-14 lt on flat highway, all 95RON petrol
Petrol consumption after install: well, same
Petrol prices: 1.4$ - 1.5$ for 92RON (unleaded), 1.5$-1.7$ for 95/98RON (premium).

LPG Gas consumption: 21-24 lt per 100km
Gas Prices: 60c-66c per litre.
Price for 100km on LPG: ~13.5$
Price for 100km on Petrol: ~26.5$
Installation Price: 2950$, 2000$ equipment, 950$ labour+taxes
Installation Price after government rebate: - 950$.
Kilometers to travel to pay installation off: ~7300km

Thats all, folks - happy to ask question or provide more photos :)
 
How is the LPG being pushed into the engine? Via the injectors? Any concerns about toasting anything since LPG burns hotter than petrol?
 
LPG is pushed (sucked, actually) with air - it is mixed on intake manifold.

From the research I've made, haven't seen anyone complaining on actually burning anything on pretty much any vehicle, and we have bloody lot of LPG vehicles here in australia, almost every single taxi is LPG, for instance.

The only real concern I have is the injectors, as they tend to get hotter when where is no petrol going through them, apparently this is solved with driving on petrol from time to time.

Another thing is, I don't know how it is fuelled in closed loop mode - was planning to either drill hole in exhaust and wire wide-band sensor there or take the rig to the dyno. Probably will take it to the dyno - i'm also curious what's the difference between petrol and LPG performance on converted vehicle.
 
I've had my LPG '80 for about 5 months now - I love it. Half the cost of petrol, and only around a 15% consumption penalty.

Mines an import, so same underslung rear tank location as yours is possible (where the spare wheel on UK demestic models sits).

Also the same system of mixing into the inlet manifold - a multipoint injection system woudl be more fuel efficient, but is also a fait bit more expensive.

Enjoy it - JB
 
Know of any fella's in FZJ80's running a Supercharger or forced induction and LPG?
 
Interesting project.

I am happy to see the payoff in under 10K km. In the US this might be interesting. Currently LPG does not have a road tax, and gas does. I may look at the cost of pay off here in the states.

How does the system manage backfires through the intake system. IMO running the lpg through the intake manifold could be done better. 6 Seperate injectors would allow better fuel control.

I see no reason you could not run a secondary ECU i.e. mega squirt for running on lpg. I also wonder if you could run lpg with unleaded and have the factory ecu manage the fuel mixture. Factory ecu would be better as there are many condition in which the ecu will fuel cut to save the engine from too lean. You may be able to run a valve for fuel cut on the lpg too off the factory ecu.

Thanks for the post.
 
What did you do with the sub tank??? Dibs if its still around :D

Interesting project, thanks for sharing.
 
P8nt- he's in Sydney Australia, do you really think he would or could ship a used sub tank to Michigan?.....I dont think so. Nice try though.
 
wow, I'd love to get that sort of gas consumption. my 80 series gets about 40l/100 km for gas and 23l/100 km on petrol and i have that mixer ring set up as well.
i think i need a retune or something.

p.s first post.

im from sydney as well.
 
Livin_Loud said:
wow, I'd love to get that sort of gas consumption. my 80 series gets about 40l/100 km for gas and 23l/100 km on petrol and i have that mixer ring set up as well.
i think i need a retune or something.

p.s first post.

im from sydney as well.
Click to expand...


When I got my 80 series converted to LPG, I was getting 45l/100kms which is way too high. I got it checked and had a balance pipe fitted that reduced the LPG useage to to 30l/100kms which isn't too bad since I run 285/75/16 M/T's, a 2 inch lift and heaps of extra weight (steel winch bar, winch, rear storage system, Engel fridge etc etc). In Melbourne, LPG is 59 cents a litre whereas 95 RON is $1.45. The conversion was one of the best things I've done.
 
Cattledog said:
Interesting project.

How does the system manage backfires through the intake system. IMO running the lpg through the intake manifold could be done better. 6 Seperate injectors would allow better fuel control.

I see no reason you could not run a secondary ECU i.e. mega squirt for running on lpg. I also wonder if you could run lpg with unleaded and have the factory ecu manage the fuel mixture. Factory ecu would be better as there are many condition in which the ecu will fuel cut to save the engine from too lean. You may be able to run a valve for fuel cut on the lpg too off the factory ecu.

Thanks for the post.
Click to expand...

So far I've made around 5000km (~3100 miles), never had a single backfire.

I'm not entirely sure of whether or not gas system has it's own ECU, it might just as well has one, considering price of equipment and complexity of wiring under the bonnet.

I do agree that feeding gas through injectors will be much better option, but as far as I see it, installation would be much more complex - in my case they just shut off injectors while keep fuel pump running (basically just return petrol in the tank), which is why, by the way, I cannot run out of petrol and continue on gas.

Factory ECU usage is also interesting thing, but correct me if I wrong, i don't see it being used in anything other than in open loop mode, since fuelling in closed loop mode will be different from petrol and factory ECU either will be given wrong fuelling or won't be working properly when on petrol.

Anyway, it seems to run pretty well the way it is. I'll probably run it on dyno in both petrol and LPG to see fuelling and power output, and I will post reports after major service at 200'000km, which is due in 11'000.

Cheers.
 
p8nt said:
What did you do with the sub tank??? Dibs if its still around :D

Interesting project, thanks for sharing.
Click to expand...

It was removed completely, along with spare wheel, the LPG tank is bloody huge. Don't miss it much though, I've got about 200-300km more range on fuel with sub-tank being swapped for LPG one.

BTW, can't keep amusing on how well TLCs are made - it just cannot be engineered better, really like simplicity of sub-tank arrangement.
 
Livin_Loud said:
wow, I'd love to get that sort of gas consumption. my 80 series gets about 40l/100 km for gas and 23l/100 km on petrol and i have that mixer ring set up as well.
i think i need a retune or something.

p.s first post.

im from sydney as well.
Click to expand...

I think you are using WAAAAAYYYY too much fuel, is it 1FZ engine? For 3FE it might be normal (that said, never used one meself), but really weird for 1FZ.

I get 23l/100km on petrol when driving in heavy traffic in city with AC on. The best I had on petrol was 13l\100km, on hume higway. LPG consumption is between 21-24l/100km, pretty steady.

Keep in mind though that LPG consumption tends to be higher in summer (irrelevent of the AC) and that I always run on 95\98 petrol, which usually give better fuel economy, especially in start-stop driving.

But you definitely need to check yours.


And yeah, Sydney rocks. :)
 
Sc0- said:
Know of any fella's in FZJ80's running a Supercharger or forced induction and LPG?
Click to expand...

Never heard of any, to be honest, probably a trick thing to certify in australia - we need engineer certificate for such mods, and the way LPG is regulated here, it is unlikely to be easy task to get supercharger and LPG at the same time.

I've heard that LPG works really well with forced induction, but never seen one.

By the way, LPG could be an awesome thing to use in intercooler, its boiling temperature is far below 0 celsium, so if someone can get intercooler to act as a heat exchanger between LPG and intake air, it would be possible to reach real low intake air temperatures...

Hmmm... Nah, too dangerous. :)
 
GAS-A-LOT! said:
I think I'm blowing smoke but....

The computer montors MAF and exhaust right? So then, It would not care if it was gas/petrol right? Also, you could probably turn of the injectors when not in use....?
Click to expand...

Thats true, technically, but the problem of what to do with petrol supply still remains.

It's probably easier to arrange when vehicle is converted to be LPG-only, but this is a sacrifice I am not willing to make :)


And again, fuel map for closed loop mode probably will be completely different from petrol one, which gets us to the second ECU again.
 
Its a 1FZ and it does 40l/100km in city/ stop-start driving. on hume highway on the way to canberra, i was able to get 15l/100km and thats the best i have ever got with the car.

was your car run on a dyno before and after lpg installation? would be nice to know how much power is actually lost when changing to lpg.

thanks for the info.
 
Livin_Loud said:
Its a 1FZ and it does 40l/100km in city/ stop-start driving. on hume highway on the way to canberra, i was able to get 15l/100km and thats the best i have ever got with the car.

was your car run on a dyno before and after lpg installation? would be nice to know how much power is actually lost when changing to lpg.

thanks for the info.
Click to expand...

40L/100 is scary, I'd go broke in first week of having that. Interestingly, highway consumption seems to be OK, 15L isn't much at all, especially on plain unleaded.

Is yours auto or manual?

With dyno, I've unfortunately missed opportunity to get it dynoed before LPG conversion, so won't be able to give comparison before\after. Mine is also auto, which sort of affects the percieved power.
 
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