Outer Limits 4x4 Board

looking at a GU ute with a gas system on it, jsut wondering if its worth keeping it, if not, how much roughly would u think to take it off??

i would suggest keep it, im running without mine at the moment waiting on a replacement part, and the fuel economy is crap. where i was using in broad terms, 12L/100km of diesel, and then 3L/100km of gas, im now using around 15L/100km of diesel alone, less power, alot less torque.

but if your deadset on removal, you could do it yourself, and just blank off whatever needs to be, which wont be much. why you would want to though i dont know, considering your not paying for anyway

cheers, andy

thanks heaps andy, thats exactly what i wanted to hear looks like i can go ahead and try buy this rig then.
all i was worried about was if it turns out to b bad, it would b costly to take off, but either way i guess its a win win situation.
thanks again

what brand system is it?

there are plenty of people on here who hate the gas systems, but in reality mines given me a few dramas but the difference it makes is worth it.

mines a D-GAS system

yeh, the fact that u can turn it on or off has to b good, im gussing things will only go wrong if u run it alot?????
im not sure of the brand, im hoping to find out tomorrow.
when u say dramas, how costly have they been?

i run mine all the time, never turn it off. i cant see the point of having it, to save it for special occasions, may aswell make the most of it, if its gonna go wrong, atleast you will know straight away if your used to having it on.

i split a convertor on the d-gas system, 30 bucks to replace. have done another one, and thats what im waiting on, but i think the terrain i drive hasnt helped...

while on my kakadu trip it developed a trick of entirely not working, until id play with it, then it would work again. then it wouldnt.

turned out to be dust in the main power plug to open the final valve

i spent a bit of time tuning it to get it the way i want it, none of the systems offer great adjustability, but all the bugs should be ironed out on a system thats already installed and been running, i did my own install.

cheers, andy

Ive got a D-Gas system that i have just got running as well and i love it. same as Andy i installed it myself so im still tuning the system but the difference without having the gas turned on is massive. did you get your truck dyno tuned again once you put the kit on Andy? im unsure whether it really needs to. its had a really good diesel tune and it needs to be able to run on diesel only. the gas is just adding more fuel and my EGTs are lower under load for the same speed than with diesel only?!?
sorry to hijack the thread..
Toddy-

yeah gas will lower your EGTs for the HP given.

i did, but just for fun, made about 30% more power with the gas on.

there is no need to dyno it after the gas install, as it compliments your diesel tune, the only thing you might be able to do, is if you have an aneroid, adjust that to give more fuel at lower boost, as the black smoke wont be an issue, but theres probably not alot of point.

what size needle are you running?
im running .040, and about 15PSI of gas pressure with the hobbs switch bridged (i would suggest checking this)
if you have too much pressure with the hobbs switch bridged, it will feel great low down, but be lacking up the top, and you will hear it knock from time to time under high load, low revs situations.

not enough pressure and you will run a needle too big, one which will feel good up top, but a bit doughie down low, probably the preffered option though, as its not gonna knock set like this...

cheers, andy

Hey Andy
Sorry for the noob reply, but by hob switch do u mean what they refer to in the diagrams as the "MAP sensor" ( realy just a boost sensing switch used to tell gas system when to inject) wouldnt bridging this make it inject gas on idle and decel? I haven't bridged it as I was unaware I needed to. the only change I made was to use an EGT gauge with a programable relay output to cut the gas for a given temperature range. (Used as a high cut to stop over-fueling)

As for the needle size I'm using the .40 aswell but I'm unsure of the gas pressure. Did u add a gas pressure gauge in? Ive just been tuning by feel erring on the side of caution.. Possible could put more gas through it but all I've been trying to do is get my mixtures right according to my fuel economy. (aiming for 20-25% gas used) I do mostly highway kms so the constant load is a good indicator I thought.
Toddy-

yeah mate, thats the thing, should have "1PSI" sticker on it.

you only bridge it for testing purposes, then hook the gas-->inlet manifold line up to a pressure gauge (your boost gauge, or a spare one) just to see what its doing, like i said, you wanna get this pressure right. just with the car running, bridge it, cause gas to flow, jamb the line into a pressure gauge and measure what its doing, definately dont drive around with it bridged. you can adjust this pressure by the screw on the side of the silver control unit.
which is actually just two poxy valves in a pretty case

which system is yours? the new black system, or the older v2 turbo lite system?

cheers, andy

Apparantly it's the black series but also says v2 turbo.. I dont think I have the silver control unit. My system runs a manifold pressure line from the manifold -> hob switch T-piece -> the gas converter. The only adjustment I have is at what boost pressure the system begins to inject (via the adjustable hob switch) and the big brass allen key nut on the front of the converter. But all this would do is adjust the spring pressure so as to change the (in very crude terms) gas map (as in how much gas is injected at the changing boost level)?? Correct me if I am wrong.

ahk

well, the adjusting screw on the silver unit i have adjusts the pressure the gas starts to get injected at, and then raises pound for pound with the increasing boost, i believe.

yours may be the same, or may be different, im still waiting to hear from D-gas the main difference with this black unit.

cheers, andy