GTR conversion to LPG

[Beer Baron]

Its like everyone always tries to be wise and predict fuel prices will hit $1, then $1.50, like they are clever or something, but its a no brainer, they will keep going up! As they do, we need to be on top of things and start some of the great mechanical minds out there think about this LPG setup. What about when the price difference is $1.50 per L! What will the difference be in 10years??

<{POST_SNAPBACK}>

umm i may have missed something here but doesn't LPG stand for Liquid Petroleum Gas? ie. not a renewable resource? I think you will find the price of LPG will rise in tune with petrol.

[thedriver]

umm i may have missed something here but doesn't LPG stand for Liquid Petroleum Gas? ie. not a renewable resource? I think you will find the price of LPG will rise in tune with petrol.

<{POST_SNAPBACK}>

correct - it is a byproduct of the oil/ petrol refining process

[psybic]

I don't know what it is, I will be sure to research it. What I DO know is that it IS NOT rising in tune with fuel. The GAP in prices IS getting bigger. Remember when PULP was like 80c. gas wasn't 80c cheaper then, but it is now!

The gap will definatly get bigger in prices. (write that down)

[Beer Baron]

LPG prices will rise also mate. it is a finite resource just like refined petrol. plus it is of inconsistent quality. plus it will cost a sh1t load to convert your car to it. plus it smells. plus it adds a fair whack of weight to your car.

If fuel consumption/cost is of real concern to you instead of wasting 3grand destroying a perfectly good GTR, spend the 3 grand on a manual hyundai excel. Drive the GTR when you want some fun, put around in the excel when you are going A-B.

I really can't see a benefit in the LPG conversion except a possible cost saving over a number of years, if you do a lot of K's in the GTR.

[psybic]

LPG prices will rise also mate.

<{POST_SNAPBACK}>

Yep. My point was just highlighted by the fact they are not rising as fast as PULP. I have no doubt they will go up. The GAP or SAVING = PULP - LPG, where bigger SAVING is gives us more savings is the concept I am talking about.

What if you had a GTR as a run around car... that would be my solution. I'd prefer a GTR with a 10% power loss than an Excel.

[Beer Baron]

but you see my point you are strapping heaps of weight into an already heavy performance car, and loosing power at the same time. doesn't seem very sensible to me. how many k's do you do in the GTR?

[psybic]

Yeah, its extra weight and less performance, its making it a less that par GTR, but a less than par GTR is not only a cool rhyme, its also a weapon compared to other vehicles on the road.

I sold mine, but when I did use it, I actually travelled 1hr to work everyday. A return trip of around 70kms, bit more... Thats 350 a week minimum, but who keeps driving a GTR to a minimum? I would often do 700kms a week in it. I'm sure others would be the same.

When time comes to get another GTR, LPG won't be on the wish list, but a few more years down the track, I can see it might be and it would be good to hear some more technical views, especially from those 10second VL's.

[thedriver]

but you see my point you are strapping heaps of weight into an already heavy performance car, and loosing power at the same time. doesn't seem very sensible to me. how many k's do you do in the GTR?

<{POST_SNAPBACK}>

You are also removing weight.. you remove the exisiting fuel system and tank and REPLACE it with the LPG system... I'm not talking some dirty-whore duel fuel system... "That's one LPG neat thanks bartender."

And if i'm doing 25,000 - 30,000 kms+ per year... in the car i want to be driving all those ks in, then it is well worth a 10% or less performance loss. Hell I can make that loss up with other mods.

So question still in the air (i haven't called C&V yet) - anyone know any AWESOME GAS installers with lots of experience in turbo'd 6s???

c'mon VL nuts...

Edited September 29, 2005 by thedriver

[browny]

Worst idea ever.

LPG is a good idea for daily hacks that rack up eleventybillion km, or as a loophole to engineer conversions where emissions are an issue (maybe they have even closed this loophole).

PS Bit of trivia. LPG doesn't actually smell. They add a chemical to make it smell so you can detect leaks.

[paulr33]

i know a guy in melb who has done a 1jz turbo running on gas, ran 10psi fine on lpg

[thechief]

If you can't afford to run a gtr on pulp you can't afford a gtr

Edited September 29, 2005 by thechief

[thedriver]

If you can't afford to run a gtr on pulp you can't afford a gtr 

<{POST_SNAPBACK}>

Did you ever take other considerations into mind? Like the environment???

I also got some more info about the new gas tanks (CTs)... they are produced by a NZ company... Propane Performance Industries

[PHATR32]

lol, if you really cared about the invorment youd be riding a bike!!!!

just admit you cant afford to keep running the gtr and get on with the lpg research!

[thedriver]

lol, if you really cared about the invorment youd be riding a bike!!!!

just admit you cant afford to keep running the gtr and get on with the lpg research!

<{POST_SNAPBACK}>

<_<

hehehe... ultimately that's true! but you also have to be practical & there's no point being an extremist. my mountainbike won't get me to the snow to go snowboarding or down to the coast to go scuba diving though...

[Sydneykid]

This thread us ever so funny, a quick recap...........followed by some thoughts…..

1. thedriver wants to do an LPG conversion on a GTR, or is it a Stagea, I can't tell?

2. So he can save money on petrol and still have the performance of a GTR

3. proengines (who builds engines, all day, every day) says he will be lucky if he saves the cost of a cheapo gas mixer conversion in 3 years. And he left out the interest cost of the money spent and the higher depreciation in value of an hi mileage LPG GTR.

4. No one in the LPG industry has been able to offer a solution any better than a simplistic gas mixer. Which will mean less performance, substantially less performance. That's not just less power but less throttle response and (just what a GTR doesn't need) much less torque at lower rpm.

5. LPG used to be high octane, over 102 ron was not unusual. But, in order to keep the price down to make it attractive for high mileage fleet users, that is no longer the case. Recent tests have shown average LPG has fallen to be 95 to 97 ron.

6. LPG contains only 66% of the calorific value of petrol, so you have to use 33% more to go the same distance. But (there is always a but) that's at a lower speed (refer #5 above). If you want to go at the same speed, then you use more than 33% more LPG, recent estimates put it at an additional 8%. So that's 41% shorter distance on the same amount of LPG.

7. LPG needs a pressurised vessel to carry it in, regardless of removing items, the LPG system is always going to weigh more. That's more weight to carry, that means less fuel economy and/or lower performance. We can argue about how much weight, but that isn't the point. The point is there IS more weight and a GTR hardly needs MORE weight.

8. There is a conundrum, if you could put the LPG tank in the same location and shape as the fuel tank it would still hold less because it is a pressure vessel (thicker walls), around 5% smaller based on some simplistic calcs. So the GTR will only travel 54% (100 - 33 - 8 - 5) as far at the same speed with the same sized tank (external dimensions). That means you will have to stop for fuel twice as often. Do a check on the frequency of LPG refills and you will find this is in fact pretty much the case, across the board.

9. The fill rate of an LPG tank is slightly more than twice as long for the same litres as petrol. So that means you have to go to the service station twice as often and spend twice as long there while you are at it. I don't know about you, but I don't have enough time now, I don't need to lose 20 minutes extra every other day filling up the LPG tank.

10. LPG service stations are pretty common these days, but they will need to be for a 100% LPG conversion. What are you going to do when it is more than 200k's to the next LPG service station? That's why there are so many dual fuel LPG conversions, you really do need a safety net. Check around the fleet managers, they will tell you that is why the 100% LPG fleet cars are not allowed out of the metropolitan area.

11. Ever tried to slip a few litres into an LPG car to get that extra kilometre to the service station? What are you going to do? Top it up from your BBQ bottle?

12. Support, you are not going to get much. Don't expect the LPG conversion industry to be very interested, they know there is no money to be made in developing a one off performance LPG conversion. Much more profitable to do the gas mixer dual fuel conversions on the hacks. Don't expect the performance industry to be too interested either. They all will think you are crazy, spending good money to go slower, add weight and decrease the distance between fills. You are on your own I would suspect.

Bottom line, as someone said about 30 posts ago, IT”S NOT GOOD IDEA.

cheers

Edited September 30, 2005 by Sydneykid

[browny]

The other thing to think about is whether LPG is going to maintain it's low pricing.

I can remember when diesel was cheap.

[thommo]

SK post = end of discussion

[psybic]

No it doesn't.

Ofcourse its hard to get started, who wants a one off project? Who wants to be the first, you are going to have so many issues it will seem pointless. Almost as pointless as the first computers, which could do simple calculations in a few minutes which a normal person could do on a piece of paper in under one minute. These computers were huge and a waste of space.

So for a one off, its not going to happen, but if a few people pull off something decent, a company or two start knowing what they are doing and specialise in this area... who knows.

The only point no one seems to understand is, you can't give calculations which suggest it takes 3 years to be viable. That is like saying all moths like pink shirts instead of blue. WTF do you base that sum on? So many variables!!!

The number one point LPG has going for it now, is the difference between the price of it and petrol. It is getting bigger, do I have to start a worm graph to prove it? How long have you guys been driving, longer than me I bet and you can't seem to notice the price gap getting bigger all the time? Its not hard to see that the savings increase as the price difference increases.

*Trips as jumps of soap box, crowd laughs, boy cries*

[NickR33]

fuel prices will stabilize.... there is no shortage of crude oil, only refined oil... as developing economies (namely China) stop exporting it and start importing it to match their local demand...

get a power fc, set the rev limit to 3000rpm, retard the timing and tune for 95 octane or even regular unleaded if your brave... just let it go man;)

[browny]

psybic, please tell me how you know that gas will always be cheap. As I said before, diesel was cheap once.

True that everyone is in a unique situation, but for someone who does around the 15k mark p.a. (ie an average driver) it's going to be three or so years before you break even. So to make it worthwhile you need to do a lot more km than the average driver, and if this is the case then I'd question whether an expensive sports car is a wise choice....