A/F Tuning with SAFC

[Mischief7m]

Hey Guys,

So I have my SAFC tuned pretty well, but i am trying to get it fine tuned, and get some peace of mind clearing up a few questions.

i read over the tuning thread in the ref section, and a few other sources as well.

i have it tuned as recomended. the few questions i have are as follows.

1) am i safe having a low 15 afr at cruising speeds (23-3300 rpm)?

2) does pulling fuel with the safc cause the ecu to advance timing?

3) am i better off having a higher fuel pressure and pulling more fuel with the safc, or having lower fuel pressure and pulling less fuel?


right now at cruise in low throttle:
I am pulling 12% and a 35 psi vac off pressure. with an average afr of 14.2 ish

and at high throttle
above 4000 i am pulling 22-25% same base fuel pressure afr of 12-13

I am running stock boost, walbro 255, afpr, safc, 550's, ic and 2.5"piping, stock Y and DP, 3" test pipe and cat back

Thanks in advance for the help,

-Trevor

 

[OneJSupra]

I'm in the process of tuning mine as well with a safc.

1-my afr at cruising speed (2800-3200) is between 14.8-15.5. That's normal IIRC, it varies due to throttle control and ecu adjusting it.
2-if you pull too much fuel safc will adjust timing and get very dangerous, some people lilke to get it close to zero as possible, idk what the safe level is but i think anything over -25 may not be good
3-still running stock fp so not sure about this one.

hope this helps, still learning afc tuning myself so i'm sure someone more knowledgeable will chime in.

 

[Mischief7m]

thanks for the response, thats good to know

can anyone chime in to let me know if i am endangering my car in anyway by pushing timing with the amount of fuel i am pulling?

thanks

 

[Mischief7m]

well, little update

i re tuned my safc, and created a tune point right at the lean spike so that i could add fuel at only that point.

so i took care of that spike, and that one is normal.

BUT it created a new one at 3000 rpm same deal, 3000-3200. same spike, to mid 16's

anyone?? i could really use some ideas here

thanks guys

 

[86_sports_1jz]

yea that happens to mine also but my hits a lean spike around 2200-2400 rpms. if i change mine tune the spike moves to a different area. i thought it was wired also

 

[Bigzavs]

have you tried upping to stock fuel pressure? like i said my friends car did that exactly, we couldnt tune out that spike, he upped his pressure and it solved it

when i had a mines ecu and safc i ran the 550s with the stock fpr, i was able to idle and cruise in the 14s and boost in the 11s and i didnt get near running out of % left in the safc

 

[Dylan JZ]

I'm in the process of tuning mine as well with a safc.

1-my afr at cruising speed (2800-3200) is between 14.8-15.5. That's normal IIRC, it varies due to throttle control and ecu adjusting it.
2-if you pull too much fuel safc will adjust timing and get very dangerous, some people lilke to get it close to zero as possible, idk what the safe level is but i think anything over -25 may not be good
3-still running stock fp so not sure about this one.

hope this helps, still learning afc tuning myself so i'm sure someone more knowledgeable will chime in.

(my AFC automatically tuned itself because my car is obviously better.. :biglaugh

 

[OneJSupra]

(my AFC automatically tuned itself because my car is obviously better.. :biglaugh

Here we go again... you do know better does not necesarilly mean faster ... :evil2:

 

[Mischief7m]

alright, ill try going back to stock FP, i just wanted to check and make sure pulling that much fuel was not going to push the timing dangerously far, as some people have warned me.