tune question

[TurboToy]

i have been trying to GET RID of this knock, so a buddy of mine told me to just to try to lower my fuel pressure so i did to 39 line off from 43 line off and brought my knock down from the 11's to 7.7 at 835 o2's so i lowered it even more to 36 line off and brought it to 6.1 at 792 02's where do i go from here i have the fuel as low as i think i can get it with out doin damage or can it go even lower? and what elese would i tune to get rid of the rest?? boost is 15lbs and the #'s were at the top of 3rd gear.

 

[John Larkin]

I hear bad things about those on-rail pressure gauges being inaccurate. Might try borrowing a high line one on a hose so you can watch it under boost. Also, add octane.

 

[Chris Taylor]

What chip are you using?

 

[TurboToy]

chip

jay carter 93 chip. don't know any of the measurements yet .

 

[Red Regal T]

I wouldn't hold 11 degrees of knock retard at WOT in third gear too much unless I had a lot of free afternoons to change headgaskets.

 

[TurboDave]

Originally posted by TurboToy
i have been trying to GET RID of this knock, so a buddy of mine told me to just to try to lower my fuel pressure so i did to 39 line off from 43 line off and brought my knock down from the 11's to 7.7 at 835 o2's so i lowered it even more to 36 line off and brought it to 6.1 at 792 02's where do i go from here i have the fuel as low as i think i can get it with out doin damage or can it go even lower? and what elese would i tune to get rid of the rest?? boost is 15lbs and the #'s were at the top of 3rd gear.

Need to complete your combo I think. Sounds like you've got tons of head/intake work done and that in combination with your big cam, well, you way under turbo'd and under injectored.

You've got what's called an unbalanced build up.

Also, as was pointed out. Try a different (better) fuel pressure gauge.

 

[Carolinaturbot6]

I agree with what John suggested. I'd want to get yourself another fuel pressure gauge so you can actually watch it while driving. At least it will tell you if the fuel pressure is rising with the boost & not acting erratic. Also adding octane will help determine if it is in fact real knock. It would seem so because of the decrease in retard with the decrease in fuel pressure though.

Dave is right on when he says you're "under-turbo'd", & probably knows more about these cars than I'll ever hope to. But, I don't know how that could cause your knock problem. Anyhow, you may want to make sure your fuel filter isn't somewhat clogged & contributing to your knock. Checking the fuel pressure while driving would certainly help us figure it out. HTH

 

[TurboDave]

Originally posted by Carolinaturbot6

Dave is right on when he says you're "under-turbo'd", & probably knows more about these cars than I'll ever hope to. But, I don't know how that could cause your knock problem. Anyhow, you may want to make sure your fuel filter isn't somewhat clogged & contributing to your knock. Checking the fuel pressure while driving would certainly help us figure it out. HTH

Doesn't really have anything to do with the knock, I was just "commenting" on the combination imbalance. I good, accurate fuel gage is the first step on getting this problem in hand first of all.

 

[TurboToy]

found somwthing elese i think

i was running a double check of all the #'s and found that the way i had the tps and the iac set i was only getting 3.90 at wot and that was really pushing it to the floor (car was not running) so i backed off the set screw all the way and reset the tps tp .42 and now it will still won't show any higher than 4.22, could this be something? the way it sits it idles good has a hesitation if you try to just hit it.... any other things to try will be appreshated

 

[Mile Hi GN]

Originally posted by TurboToy
boost is 15lbs and the #'s were at the top of 3rd gear.

What is the octane of the fuel?

The TPS may take some tinkering but look for .42 to .44 at idle and 4.50+ at WOT. IAC effects TPS so you kind of need to do both at the same time. Be patient.

Did you have that tip-in stumble before you reduced the fuel pressure, or did it just start with the TPS adjustment?

 

[TurboToy]

#'s

the way it sits right now the fuel pressure is 36 with line off, the tps is .42 and the iac right now cold start was at 113 and then after it idled down it was at 93 then i killed it.book says it should be 10-50 idle so it is kinda high. the oct of fuel i am running right now is pump gas 93. and my wot right now on my tps is only 4.2 and when i set the iac and the adjustemnt screw it will only hit 3.9 at wot and thats really pushing it in the carpet to get it there.

 

[Mile Hi GN]

Re: #'s

Originally posted by TurboToy
the oct of fuel i am running right now is pump gas 93.

That may be all you can get away with is 15 PSI at the top of 3rd with 93 Octane. How much 3rd gear timing? Maybe alky injection?

Originally posted by TurboToy
and my wot right now on my tps is only 4.2 and when i set the iac and the adjustemnt screw it will only hit 3.9 at wot and thats really pushing it in the carpet to get it there.

You may have to carefully open up those oblong TPS slots with a rattail file. It's a common problem, might try a search here and at GN/T-Type.

GN/T-Type: Mailing List Search

 

[Chris Taylor]

The TPS can be set for the high number without using a file. It is hard to explane. If you are going BG I will be glad to set it for you and recal. your IAC. If not, send me a e-mail and I will explane the process

 

[TurboToy]

...

i got the tps set to now (finally) it will hit 4.90 at wot and is set at .42 at idle have not road tested yet but an goin to tonight. i got all the rest of my #'s pretty much right on target so i will post to see if this helps any, thanks for all your replys to this prob you all don't know how much help you have been. thanks again

 

[TurboToy]

test run

went for a test run did still see some knock i saw a 1.2 almost right off as i hit it and then i stoped and did a dry stop and saw 7.7 all the 02 '# are around 835ish did another little run as i was comming back home and scanmaster showed a 0.0 knock and 800 o2 but i don't remember how hard i hit it, seems to respond better to the tps change and the fuel guage , had my wife watch it as i power stalled it and with 7 lbs of boost pulled (tires fixen to break free) she said the fuel guage almost hit 60 static is 42. other numbers the iac is in the 70's?? seems to high and the blms is 115 which to me is right on and the tps is 42 and wot is 4.8-9.