V8 To go on straight gas.

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ET87
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Location: melbourne

V8 To go on straight gas.

Post by ET87 » Wed Sep 26, 2012 2:48 pm

Hey guys I have a v8 vr statesman daily and wanting to go straight gas as petrol is a killer and spending 200 bucks over 10 days kills me. Wanting to know of any probs doing it, or if any1 knows about it pro's and con's. Cheers.

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JETETT
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Post by JETETT » Wed Sep 26, 2012 3:21 pm

only thing with gas is using the old conventional setup using a converter and mixer seems to use a lot of gas and Ur forever at the pump filling up, u can tune them leaner to use less gas but backfiring back through the intake is an issue and u will be forever changing ur air box and intake pipe. the system is cheap to buy and u should not have any probs finding a second hand system.
expect 200km around town and at least 3 to 350km highway driving.

vapor injection still uses a converter to turn liquid propane into gas, the vapor is then sent to an injector bank and from there with the use of its own computer system it is sent to the cylinders in sequential ect depending on ur setup, the only down side is the system it isnt direct, still running hoses in between the injector bank injectors to plumb into the inlet runners to deliver fuel, a fitting has to be tapped into the inlet to attach the hoses. it becomes a pain cause every fitting being tapped has to be the same distance from the inlet flange closest to the head and every hose length for each cylinder has to be exactly the same other wise it will be a tuning nightmare with injection delivery times being different cause one hose is shorter than the other ect you can tune and change individual injection timing and balance it out. but requires constant attention. still alot of $$ for the system not really worth it

Direct liquid injection is the ducks nuts, massive power gains and better fuel economy. basic and less components, direct injection is exactly that installed on a 4cylinder engine it would use 4 side fed injectors much like the the sr20 injectors it has its own fuel rail, pressure regulator and fuel return, inside the gas tank is fitted with a fuel pump, it is exactly the same as the petrol system but with the injectors you attach a small probe like hose at the end and have it pointed right above the valve and it will inject super cool liquid straight into the cylinder. barely any tuning needed it just mimics the standard computer system, the system doesnt use a convertor to heats the gas up it just uses straight liquid. expect to pay $2000 up to $4000
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Timmzy
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Post by Timmzy » Thu Sep 27, 2012 12:06 pm

I have a VQ V6 on gas as a dual fuel setup. So traditional converter setup etc.

I do 1000kays a week and it uses ~$80 of gas per week.

I get around 480-500km out of an 80L tank of which 72L is useable. Its very economical and works out to be $0.49 per km to run the entire car for the year.

They have the old converter systems a little better than they used to be. IE my system watches the oxygen sensor and the water temp sensor in a piggy-back setup. It also has a little computer box in the engine bay to do this with a coupld of LED's on it to indicate mixture settings and an adjustment screw/pot.

So they are not as bad as they used to be.

The biggest killer for backfiring on these - and they are known for it - are poor plugs and leads. You have to keep good air filters up to it as well - for the same reason.

If I were you I'd sell the car and get a V6 and put gas on it. BUt if you are insistent on keep ing the 5L then get a gas system put onto it.

Given the value of the vehicle I would not be able to justify the cost of liquid or direct injection gas. I don't thnk its worth it. True direct liquid LPG is only possible on an engine with direct injection position next to spark plugs. Only new V6 SIDI have that. The rest of the setups would be as stated side feed which isn't techniclally direct injection.

Darren.
Race it.

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ET87
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Location: melbourne

Post by ET87 » Thu Sep 27, 2012 10:32 pm

thanks for the reply guys, appreciate it.
i am looking to put an edelbrock manifold on instead of an air box. i got quoted 2,300 with manifold. im convinced as the mechanic has the fastest street driven HQ gts. lpgas1 r his plates n the car is white. only reason i dont wanna sell it as there is a rebuilt motor in there n she is amazing to drive n looks sexy. the set up was gonna be a single mixer, single convertor but i can go twin mixer and twin convertor at a cost tho. not sure wat system if its vapour or direct injection or if it will run on supa gas or just standard LPG. lpg octane is around 95 I THINK not sure and propane is at 110 I THINK not sure again. over 6 months if not less the gas system will pay for it self.

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