L67 super6 on LPG Injection?

[lein]

although you use more gas than fuel so dunno how it would work out economically

That might be true of the old mixer setups (~20-30%) and of the vapour injection (~10-15%) but the liquid injection LPG is as good as if not better in some circumstances because of the higher octane and the cooling effect of the liquid changing states to vapour in the head and absorbing heat.

 

[DAKSTER]

i had gas..
Wasnt saving any money
took it out
More power
Drives better
SCREW GAS IT SUCKS

in my humble opinion

You had dual fuel, badly tuned. Any dual fuel car is a compromise when it comes to tuning to begin with, let it get out of control and you are looking for trouble. Even a mixer system though, in good condition and tune, saves a lot of cash with minimal power loss. I have been using LPG for many years. You should have persevered.

That might be true of the old mixer setups (~20-30%) and of the vapour injection (~10-15%) but the liquid injection LPG is as good as if not better in some circumstances because of the higher octane and the cooling effect of the liquid changing states to vapour in the head and absorbing heat.

Agreed. Liquid injection is very cold at the injection point and this helps considerably. How cold is the expanding gas in a bbq bottle when you open the tap? Thats exactly how cold the LPG is when it arrives in the combustion chamber. Also, modern engines can handle so much more, even if it wasnt cold you wouldnt be burning valves etc.

LPG is 106-110 octane so tuning for it can only gain you power, and liquid injection vs a gas mixer system is like EFI vs a single barrel Stromberg in terms of efficiency.

I doubt you would lose any economy at all, you would certainly gain power in a correctly tuned engine, and you still get to pay half the price for fuel

 

[DAKSTER]

This Mustang has a 4.0L six (donated by an AU Falcon ex taxi !!! ) and runs low 9's on LPG.

 

[Trikky]

yep no comparrison between the old mixer systems and the injected LPG systems
Many years ago I had a 5ltr on straight LPG using a mixer and it was ok but nothing fantastic, about 12mths ago I converted my VS V6 to vapour injection and love it you can hardly tell the difference in power between petrol and LPG and on a long drive it gets down to just under 10l/100 on LPG, the liquid injection is better again as Dakster has already mentioned

 

[frogsta]

Factory LPG holdens are pretty bad. Mine was sprintgas, also used a mixer but got about 350km to a tank wheras a full tank of petrol gets me 400-450, so I guess more around 20%

 

[Loaded Dice]

Mine is dual fuel, it still starts on petrol when cold then flicks its self over to LPG once the engine temp reaches 33oC (I think, may have wrong temp there, but something along those lines) In summer it just starts on petrol, nothing for me to do, it just does it.

They reccomend that you run on petrol every now and then, if for no other reason than to keep fresh juice in the tank, burn up the old stuff, so I use about 20L of petrol a month, and over 100L of gas every week.

Keeping in mind that it runs colder plugs and is tuned to perform at its optimum on LPG, my car only uses 600ml per 100km of petrol more than the fuel economy figures that come with a factory petrol car, but also gets the same economy (13L/100Km) on LPG.

As for power, I really should put mine on the dyno, pitty I didn't before I had LPG fitted to see exactly what gain or loss there was, but when switching between the two, it feels to me to have increased power on LPG, but again, it is tuned for it, but having said that, I may or may not have (lol) had a run UP Anthonys cutting with a MY11 model on petrol, who no longer laughs when he sees an SSV on LPG.

 

[westerlybreeze]

I heard some sort of special injectors have to be used for liquid injection, what truth is there to that? .. can normal injectors be used?

 

[DAKSTER]

I havent gone into it that far yet, my LS3 is still wrapped in plastic and comes with no induction system at all, just an empty valley. I would assume that if different injectors are required then the gas people would fit them with the gas? I'll let you know when it all starts happening

 

[pjdm1980]

I had the vapour injection on my old S/C Stato and it was great with only slightly more gas per 100 than petrol with no noticeable power loss then I moved up to the LS2 GTS with JTG injection and it get pretty much identical economy on both fuels and its up 10rwk's on the JTG system.

 

[DAKSTER]

I had the vapour injection on my old S/C Stato and it was great with only slightly more gas per 100 than petrol with no noticeable power loss then I moved up to the LS2 GTS with JTG injection and it get pretty much identical economy on both fuels and its up 10rwk's on the JTG system.

But thats impossible!! Everyone knows LPG sucks for both power and economy.. LPG is for BBQ's they tell me !! :rofl2:

Seriously, thats just proof of what I am saying.. LPG is as good as petrol or better for both power and economy with the right system and tune, and STILL costs half the price..