Sorry I'm so dumb, but I've been trying to tune my car and now everything has me confused. Ok first off I know you souldn't tune by O2 readings, but what is the ideal voltage for the car to be running at during WOT, I've been told .50 volts, but I'm not sure. Next is a fuel question, I'll just tell you my set up and take all the comments on how I need an afpr and smaller injectors, but here it is...I have a 255lbh fuel pump, 650 injectors, stock fpr, safc and stock 14b set at ~16psi. my low throttle settings are about -30 all across, and i've been changing my hi throttle all the time, but at -50 from 2000RPM up and when boost gets up to about 5psi it starts knocking really bad and O2 reads .78-.85. Now I know you all are going to say that I have way too much fuel with the 255 and 650's but with the safc turned all the way down to -50 it shouldn't still be running that rich should it? I'd appreciate any input at all, thanks.

93 Tsi AWD-SAFC I, Apexi N1 turbo back, MBC, K&N w/ hacked can,
Walbro 255, Accel wires, 650cc injectors, stage 3 dsmchip

97 Neon ACR-Stock

Well in terms of start off settings, do the quick math. 650's are 200 ccs bigger than 450's. 200/650 is 30.7%, so let's call it 31%. Set the SAFC at -31% across the board and you have stock fuel levels just like if you had the 450's in there. Taking 31% off 650 leaves you with the 450's, so you have a "zeroed out" starting point. Now, no "too much fuel" problem to worry about. You were overcompensating WAY too much by making it -50% when ou are in boost in hi throttle. You are now basicaly running 325 cc injectors at 16 psi on a turbo car. Way Lean, much knock, engine explode.

As far as O2's go: With 91 octane, you'd like to see .93 or so, give or take a few hundredths. With higher octane, that number can dip to .91 or so, and with race gas, into the high to mid .80's. When you are getting .75-.85 on pump gas, you are way lean. WAY lean and I can see why you are knocking. The 14b at 16 psi will likely need a few extra % in the small end (1000-4500 rpm) and even more fuel going up to redline. Tune the Hi settings first. It' easiest to set the lo and hi points at 20% and 80% respectively. Then once you have the car tuned for hi setting's just leave the low settings close to stock, or maybe a little richer than stock. At less than 20% throttle, your fuel trims aren't super important. You're cruising at that level so knock isn't much of an issue. Anywhere in between in partial throttle, the SAFC will create the proper trim based on an average of the lo and high settings for that point.

It's running again shitheads.

http://www.dsmregistry.com/detail.php?carid=791

HybriDSM@gmail.com ; HybriDSM@hotmail.com

Think for yourself. Question authority does not always mean disagree with authority.

If life were perfect, I'd be Calvin and you'd be Hobbes.

__________________________________________________________
-Tony <--- NOT asian.
'06 Wicked White EVO IX

wow, I guess some of my information was a little off, or maybe more than a little. Thanks for telling me before I blew up my car. I got everything set a little better lastnight, and knock calmed down a lot, so now I guess I'll try to fine tune it today. One last question though...Does anybody else have a problem with extremely high oil pressure? I don't mean it goes up and comes back down after a while, I'm saying it is always way up there.

93 Tsi AWD-SAFC I, Apexi N1 turbo back, MBC, K&N w/ hacked can,
Walbro 255, Accel wires, 650cc injectors, stage 3 dsmchip

97 Neon ACR-Stock

I just wanted to say Matt did an awesome job with his reply.

Originally posted by Jeff_99gs
I just wanted to say Matt did an awesome job with his reply.

__________________________________________________________
-Tony <--- NOT asian.
'06 Wicked White EVO IX

Agreed. Very well put.

Ok it seems like my 02 sensor doesn't want to go above .89 volts, and I was even killing my car with too much fuel(black smoke/bogging-rich knock). How high are these sensors supposed to go. Also on high throttle with 2000-7000 set at -25 my o2 reads .76...I'm guessing problem. Is the voltage problem a sign that my o2 is shot or what?

93 Tsi AWD-SAFC I, Apexi N1 turbo back, MBC, K&N w/ hacked can,
Walbro 255, Accel wires, 650cc injectors, stage 3 dsmchip

97 Neon ACR-Stock

What I'm saying is that under WOT my o2 only reads about .76(lean I know)with the hi throttle settings at -25, however it keeps sputtering and has really black smoke(from too rich). My question is what do I do since I'm bogging my car down from too much fuel (rich) while the o2 is saying that it's running too lean. and as soon as it gets past 5lbs of boost the knock sensor goes crazy and shoots all the way up, no matter what the hi throttle settings are(richer or leaner)

Edit: I have a pocket logger with the MMCd, but how can I upload it to my computer? Also I have a chip that converts the factory boost gauge to a knock gauge, so that's what I mean by the knock shoots all the way up.

93 Tsi AWD-SAFC I, Apexi N1 turbo back, MBC, K&N w/ hacked can,
Walbro 255, Accel wires, 650cc injectors, stage 3 dsmchip

97 Neon ACR-Stock