A few quick questions about tuning SAFC

[Sayajin]

Well anyway, here is my question. I am finally getting around to tuning my SAFC with my datalogger and a few questions have arisen. I hope you guys can help me out, Remember I drive a 90 GSX and the settings for that are slightly different:

1. When tuning Low Trim, do I worry about knock? At about 1593rpm I have 1 count of knock, 2468 I have 4 counts, 2591 I have 3 counts, 3000rpm I have 1, also 1 count at 1437 rpm. My low fuel trim is steady at 102.3% across the board. Also since I did not go WOT I do not have a steady o2 sensor reading to give since it fluctuates when you are not WOT. Should I lower my trim to below 100% to get rid of the knock? Or do you not worry about it for low trim?

2. When doing a WOT run, do I do it in 2nd or 3rd gear? I did a 2nd gear WOT run and did not have much knock, so I was going to do a 3rd gear and then set it using those readings, however I wanted to make sure that was correct.

3. When setting LOW Trim, since you dont go WOT your o2 does not remain steady. Does this mean I ignore o2 when setting these? Or should it fluctuate between certain numbers?

4. My trims, both high and low, remain the same across the board at pretty much any RPM, is this normal? or should it be slightly different at different RPMs?

5. and one more question, so if I notice knock at a specific RPM when i do my WOT runs and I am richening the mix, do I want to make a rpm point or whatever its called for that specific rpm, such as 3426rpm and then richen that? or do I just leave the rpm points at the defualt ones they are now and just richen the 2 points which it is inbetween? Such as riched 3000 and 4000rpm by a click or 2? Or do I make a 3500 point and richen that?

Thanks a lot guys and I really appreciate the help. I am quite anxious to finally get my SAFC settings properly set.


-Sayajin

 

[TargeT]

tune for zero knock

do your pulls/logging in 3rd or 4th (if possible, remeber to be safe)

 

[kristmen]

Well its best to tune for 0 knock but sometimes you just cant.

A bit of lock, like 3~5ish is fine.

 

[TargeT]

Originally posted by kristmen
Well its best to tune for 0 knock but sometimes you just cant.

A bit of lock, like 3~5ish is fine.

ya, i have knock on the lowend, but i dont care if it pulls timing down there, no knock up high (or no more than 3 counts) is crucial, because A) your engine gets damaged and B) your timing gets pulled

 

[kristmen]

You wont get much damage from a couple counts of knock if any.

Infact some guys tune for a couple counts of knock.

I'm tuned for about 3 to 5 myself and the car seems to run good.

 

[BIGGSIE]

"3. When setting LOW Trim, since you dont go WOT your o2 does not remain steady. Does this mean I ignore o2 when setting these? Or should it fluctuate between certain numbers? "

Yes ignore the 02. Watch the feed back trim. I assume you are trying to set it up in the driveway, once you get it close drive it a little and you will see the trims start to change. If you haven't already pull the EFI fuse near the battery for about 5 minutes, this will reset your trims to 100%.