AU3 XR8 on LPG ?

TIC-302 · 19-08-2005, 03:18 PM

With fuel prices going through the roof is it worth installing an LPG system. I'm aware that it's a performance car, however the current fuel prices are giving me the s! $1.26 for unleaded and much more for premium, LPG is $0.46.

Would you convert?

jspec_sti · 19-08-2005, 04:17 PM

ouch, no way!

:

Steffo · 19-08-2005, 05:07 PM

Definitley. LPG is an excellent fuel, and being twice cheaper then petrol doesn't hurt.

supa eb · 19-08-2005, 05:26 PM

Straight gas would be more the way to go for a v8. Dual-fuel (gas and petrol) is more for everyday family cars. An xr8 is NOT meant to be a family car. If you were to run it on gas alone, raise the compression and have it tuned for gas, she'd run really well, give you great performance and be pretty cheap to run. From what I've read, running on lpg causes less engine wear then petrol. I'm not sure how much more it'd cost to convert to straight gas, rather than dual-fuel, but it's definitely worth a look. However, if your AU is a family car and you're not after performance, dual-fuel is certainly a good option, even though she won't give you as much power.

XplosiveR6 · 19-08-2005, 05:37 PM

[QUOTE=supa eb]running on lpg causes less engine wear then petrol./QUOTE]

actually its quite the oposite, that is why factory gass engines have hardened valves as gas simply doesnt have the lubricating characteristics as petrol does.

if you must, streight gas is the only way, but expect a loss in power

Gambit · 19-08-2005, 05:45 PM

Quote:

Originally Posted by EF_Dave

if you must, streight gas is the only way, but expect a loss in power

Why should you expect a loss in power?

jspec_sti · 19-08-2005, 05:46 PM

Replace the egg beater (RX7) with an economical buzzbox (gassed up Pintara perhaps

sorry couldn't resist Steffo) and for God's sake leave the XR8 alone! Converting it to gas is about as bad as following the Poms in The Ashes...

JC · 19-08-2005, 05:48 PM

[QUOTE=EF_Dave]

Quote:

Originally Posted by supa eb

running on lpg causes less engine wear then petrol./QUOTE]

actually its quite the oposite, that is why factory gass engines have hardened valves as gas simply doesnt have the lubricating characteristics as petrol does.

if you must, streight gas is the only way, but expect a loss in power

Pull yourself into the 21st century! ALL cars these days, that run on ULP, already have hardened valve seats. Older motors than ran on Super (Leaded) didn't have hardened valve seats as the lead in the petrol helped to protect the valve seats and generally lubricate the system.

About the only difference between a straight gas motor and a ULP motor these days would be compression ratio, spark plugs and possibly thermostat.

Having said that, if you go the traditional mixer in the intake pipe method, you WILL lose a heap of power (approx 10 to 15%), but if it's an AU3, then you will still be left with as much power as an AU1 (roughly). I would go straight gas as it's the only way to maximise the engine tune - dual fuel is always a compromise on tune as the tune needs to be different for petrol and gas.

Steffo - what the hell is twice cheaper? Do you mean less than half? Where the hell did you/do you go to school, and what language do they teach there? LOL.

Steffo · 19-08-2005, 06:17 PM

[QUOTE=EF_Dave]

Quote:

Originally Posted by supa eb

running on lpg causes less engine wear then petrol./QUOTE]

actually its quite the oposite, that is why factory gass engines have hardened valves as gas simply doesnt have the lubricating characteristics as petrol does.

if you must, streight gas is the only way, but expect a loss in power

LPG causes valvetrain wear (generally in older cars), sure, but it also increases oil life. Petrol contaminates the oil, leading to lesser oil life, and dirtier oil.

And why should there be a power loss? Bump the compression and adjust ignition timing.. and there should be a power increase if anything.

Quote:

Originally Posted by Gambit

Why should you expect a loss in power?

You shouldn't, its just a popular myth about LPG.

Quote:

Originally Posted by JCXR8

Steffo - what the hell is twice cheaper? Do you mean less than half? Where the hell did you/do you go to school, and what language do they teach there? LOL.

Haven't you ever heard of colloquial English.. or put more simply.. slang? Or do you expect absolute perfection?

JC · 19-08-2005, 06:29 PM

Steffo - I have, and yes I was having a laugh. I just wasn't really sure what you meant!

When you do an LPG conversion that mixes the gas in the air intake tubing, you will lose power as you are restricting the intake from 75mm down to about 50mm, therefore reducing the available fuel/air mixture. Also, you cannot advance the timing etc on an AU1/2/3 XR8 - not without a chip of some sort. So, if all you are doing is a "traditional" LPG conversion, you will lose power. But there are ways to get the power back - at additional expense, of course (or should that be half cheaper, LOL).

Qwikcorty · 19-08-2005, 06:38 PM

Quote:

Originally Posted by Steffo

And why should there be a power loss? Bump the compression and adjust ignition timing.. and there should be a power increase if anything.

a power loss is because a lpg carby needs to use a smaller throttle to suck the gas through, and wont flow nearly the same as a 70mm throttle body. GRA throttlebodys/carbys are under 60mm diameter.

Psycho Chicken · 19-08-2005, 06:45 PM

Quote:

Originally Posted by Steffo

LPG causes valvetrain wear (generally in older cars), sure, but it also increases oil life. Petrol contaminates the oil, leading to lesser oil life, and dirtier oil.

Gas contaminates the oil too, just because it looks clean doesn't mean it is.

jonbays · 19-08-2005, 06:55 PM

I reckon dual fuel would just spoil the car and spend more on conversion than you would save in quite a while.

A proper performance lpg only set up would be very nice but there are few people who can do it well and they cahrge well for the work and parts.

Seriously if you can't afford the fuel for a V8 sell it and buy a cheap to run dogbox car for a couple grand or better still a bike (motorcycle that is) to run around in and use the XR as a weekend warrior. Cost you about the same really when you add it all up.

TURBOTAXI · 19-08-2005, 07:05 PM

This is a conspiracy.
GAS Is great. I think the only reason people say you should not use it is because they are trying to protect the secret.
I am yet to come accross a person who has gas and thinks it is bad. I am also yet to see anyone remove gas from a car, because they dont like it.
Do it. You will feel like you are getting away with something everytime you fill up.

Steve_T · 19-08-2005, 09:00 PM

Get yourself one of these setups...

www.gas-injection.com

!!

**DJM83** · 19-08-2005, 09:19 PM

Quote:

Originally Posted by TURBOTAXI

This is a conspiracy.
GAS Is great. I think the only reason people say you should not use it is because they are trying to protect the secret.
I am yet to come accross a person who has gas and thinks it is bad. I am also yet to see anyone remove gas from a car, because they dont like it.
Do it. You will feel like you are getting away with something everytime you fill up.

With the currnet price of fuel and in recent times if u bought a car on LPG why the hell would u remove it? but i think ppl that drive (well most) LPG powered cars look 4 them in the begining i agree LPG is cheap but after owning 2 cars on lpg id never own another
btw it takes about 20000kms or more to re coup ur money forked out 4 the conversion

GK · 21-08-2005, 06:26 PM

Quote:

Originally Posted by TURBOTAXI

This is a conspiracy.
GAS Is great. will feel like you are getting away with something everytime you fill up.

Right on!

GK

XplosiveR6 · 21-08-2005, 08:28 PM

Quote:

Originally Posted by Steffo

You shouldn't, its just a popular myth about LPG.

Is the BF gas falcon having only 157kw while the petrol version has 190kw a myth?
Thats alot of power to lose

T_Terror · 21-08-2005, 09:24 PM

why would the BF gas falcon have less power than the BA gas model?

**Mechan1k** · 22-08-2005, 08:06 AM

I think it was the AU EGAS motor that was 157kW .... the BA was close to the 165-170kW mark.

There is a difference between the 2 ... I have an AUII EGAS ute .. and my fiancee's father has a BA MkII EGAS ute ... mine runs well ... but nowhere near as good as the BA ... mine you the BA is having probs with the spark plugs and smooth running comapred to mine.

But hell ... the BA EGAS motor goes pretty damn good ... I was surprised ... much better than the AU EGAS motor

Kenaz · 22-08-2005, 09:40 AM

I think the AU straight gas motor is around 136kW. The BA E-gas is definitely 156kW same as BF.

Kenaz · 22-08-2005, 09:41 AM

Quote:

Originally Posted by Mechan1k

But hell ... the BA EGAS motor goes pretty damn good ... I was surprised ... much better than the AU EGAS motor

What the? No way! The BA E-gas felt about as quick as my old 3 speed EA.

TIC-302 · 22-08-2005, 12:22 PM

thanks for all the input. I sure stirred things up !

**Mechan1k** · 22-08-2005, 06:51 PM

Quote:

Originally Posted by Kenaz

I think the AU straight gas motor is around 136kW. The BA E-gas is definitely 156kW same as BF.

That explains it then ... well it should ... i made 99.xkW at the rear wheels ... so yeah ... sounds right to me

**Mechan1k** · 22-08-2005, 06:53 PM

Quote:

Originally Posted by Kenaz

What the? No way! The BA E-gas felt about as quick as my old 3 speed EA.

Well top-end isn't the best in the BA EGAS ... still better than the AU though.
Low down though ... the BA EGAS has punch though (mind you it is a tray back XL model)

GlennBA · 22-08-2005, 07:14 PM

Quote:

Originally Posted by Kenaz

I think the AU straight gas motor is around 136kW. The BA E-gas is definitely 156kW same as BF.

AU
4.0L Intech Dedicated LPG 6 cyl
Bore and stroke: 92 x 99 mm
Power: 143kW at 4500rpm
Torque: 362Nm at 2750rpm
Overhead camshaft, 2 valves per cylinder
Fuel system: EEC V fuel injection
Compression ratio: 9.6:1