AFC/logger tuning questions

[sypderdude31]

I have a 98 4G64 Spyder with numerous mods and am collecting
parts to go turbo. I've read tons of tuning guides (mostly geared for
turbo'd engines) and appreciate some tuning advice for maxing out
my car while still N/A. I have a pocket logger
and SAFC for tweaking my a/f. I read Kyle's tuning guide for OBDII
and have a few questions:

1. Are LTFT trims different for each RPM range? (I notice my LTFT at around 5% but they change while driving up to 9%)
2. Should you add LTFT and STFT for each RPM and adjust or just try to
zero out the STFT at each RPM level (1k,2k,3k, etc..)?
3. On a NA motor, I was told you can go MUCH leaner for WOT (.70-.80). Is this true and what kind of O2's can I lean my AFC out to for max power and timing without putting the engine at risk?
4. Is airflow the only thing an NA ECU uses during WOT to advance timing? My WOT pulls are 17-19 of timing right now at about .82 on
the pocketlogger O2's. Thanks-

My Mods:
www.geocities.com/chadberg_99/spydermods.html

 

[Blk_99gst]

1. Are LTFT trims different for each RPM range? (I notice my LTFT at around 5% but they change while driving up to 9%)
- Yes, for a 2g, LTFT change as you move through the rpm band. I don't know if they change every 1000rpm, but they do change. And I believe at any rpm, if you take your foot off the gas and decelerate, the LTFT will display the idle LTFT value (even at 4000rpm)

2. Should you add LTFT and STFT for each RPM and adjust or just try to
zero out the STFT at each RPM level (1k,2k,3k, etc..)?
-Don't worry about STFT too much. They change back and forth that they will never stay zero. Focus on getting the LTFT values to zero. If you are crusing at 2500rpm and LTFT is zero, then you hit 3000rpm and the LTFT jump to +5%, then I would adjust the safc for the 3000rpm point and richen it up 5%.

3. On a NA motor, I was told you can go MUCH leaner for WOT (.70-.80). Is this true and what kind of O2's can I lean my AFC out to for max power and timing without putting the engine at risk?
- Can't help you there. But I don't see why you could run that much leaner on a n/a motor. Something for the turboing na forum.

4. Is airflow the only thing an NA ECU uses during WOT to advance timing? My WOT pulls are 17-19 of timing right now at about .82 on
the pocketlogger O2's. Thanks-
-Not sure about the na's ecu, but for a 2g turbo ecu, timing advance is based on lots of factors. Mainly rpm and airflow determines what timing you get. But if you get any knock, timing can get pulled. Too hot of coolant temps and your timing can get pulled.