Duel Fuel XR8 Advice

FPV8U · 22-01-2006, 04:05 PM

G'day guys a mate of mines dad brought a Duel fuel 2000/2001 XR8 ute it is the 185Kw Engine with a five speed it has dealer fitted duel fuel, the car has been fitted with Pacemaker Extractors and a full exhaust, and is soon to have G & D Airbox, my question is what else can be done to improve performance on a Duel Fuel car, it doesn't run really well on petrol or Gas and he is looking to improove this on both fronts.

Edit has been looked at but it would mean everytime he want's top swich to or from LPG that he has to Re-Flash the computer, so what other options are there i assume a chip won't work for similar reasons, is the only way to go to swich to a strait gas car or is there other options that we havn't found?

Thanks Guys

AWD Chaser · 22-01-2006, 04:48 PM

My guess is that if it don't run well on either, tune it to gas only - that way you will probably get more performance out of one, then trying to get the best out of two.

JC · 22-01-2006, 06:54 PM

My AU1 XR8 (also 185kw motor, similar mods except I also have 1.72 ratio roller rockers) is dual fuel. It only has problems at idel when started and changed over to gas. If I let it idle for 60 seconds, then no issues, and once it's been running for a while it's fine (until you turn it off, and restart, and switch to gas). My system switches to gas after starting by reving to 2100rpm, and it switches over when the revs come back down.

As for performance on gas - get it dyno tested on both fuels. Mine only has 6 rwkw less on LPG than petrol and pulls equally well on either fuel.

I reckon if it runs bad on each fuel, it is not a fuel problem, but something else - perhaps a crack in the intake manifold, or a split in the intake tubing - something along those lines. Best bet would be to take it to a well respected LPG tuner - I can recommend one in Canberra (Dave Elliot at Gas Tune in Tuggeranong), but that's probably little use to you.

Mr Cube · 23-01-2006, 04:38 PM

Assuming everything is running good, I think the UniChip can run different maps depending on the fuel without the need to re-flash everytime you swap over.. not 100% but I remember ~nudge~ saying something about it, thats why he wasn't keen on an edit..

FPV8U · 23-01-2006, 05:59 PM

Thanks guys will pass on he said he would take it too a Gas tuner but is there really anything they can do without an Edit or UniChip for example?

JC · 23-01-2006, 06:46 PM

Yes - the problem may be with cracked manifold, or faulty converter (for LPG) & injectors (for petrol). It could be clogged air filter (would affect both), a dirty Throttle body - etc. The list is endless.

27-01-2006, 05:30 PM

Hey,
I have an AUII V8 5 speed on duel fuel.
It runs dodgy at idle and was running like poo on gas. I took it a gas dude and he replaced the gas and air filter. (I thought that they didn't have a gas filter) It runs fine now on gas but still runs dodgy at idle. The gas dude said it may be either my crank angle sensor or may cam angle sensor.

I hope this helps.

TheSneakiness · 27-01-2006, 05:34 PM

Quote:

Originally Posted by Mr Cube

I think the UniChip can run different maps depending on the fuel without the need to re-flash everytime you swap over..

Yep, it does.

My Unichip is going in next Saturday for dual fuel tuning with Unichip, that's when I get my car back, and hopefully everything is dialled in properly with the cam too... or else I'm running it into a wall...