Set the Low Throttle point to 69%, and the High Throttle at 70%.
Zero out everything on the Low throttle map.
Tune ONLY on WOT. The TCCS will compensate whenever it is in closed loop. Also known as part throttle, since the ECU goes into enrichment mode (a form of open loop) under WOT. When you lean out the mix, the ECU senses it and makes changes to get it back to normal. Then your WOT mixture is also affected.
http://i80.photobucket.com/albums/j187/isnms/Supra/vffueltrim.gif
I have been running mine like this for several months now, and it held the first tune i did on it. One trick that helps is to use the blue wire (normally for MAF Voltage input) and hook it up to the Vf output pin on the ECU. That way, you can see if the ECU is happy or not just by going into The ETC... Sensor Check option on the SAFC.
Vf:
0 volts: full rich
1 volt: rich
2-3 volts: OK
4 volts: lean
5 volts: full lean
When driving around, this number should stay at 2-3 volts. If not, the ECU IS making changes by itself! The idea is to work with the ECU, still trick it some, but also cooperate at the same time.
Very quick run down:
At WOT, I would say generally 10.5 is where the stock ECU likes to be. 11.5 is a safe tune. 12.0 is a good performance tune. 12.5 is where things getting quite risky. 13.0 isn’t good. At WOT, the ECU ignores sensor inputs (open loop), so it isn't compensating. That's why you can tune with the S-AFC. At idle you should see ~14.7, cruising will vary across the board because of ECU control, throttle position and other variables. The stock ECU retards timing sharply at ~5,600RPM so SAFC tuning anything above 5,600RPM is relatively pointless.
SAFC advances timing as it pulls fuel due to the nature of dinking with the AFM frequency to trick the ECU into thinking that it's flowing less air, so it puts in less fuel, and puts in more timing advance. Basic SAFC 101. This is a good thing, and a bad thing. More timing + less fuel = more power BUT too much timing and not enough fuel are very bad. You probably have no way of knowing what your timing is once you're running, so set your base timing at 8-10 (for safety) and try not to advance the S-AFC farther than -20%. What you are doing is adjusting fuel while reducing the risk of over advancing timing (which can cause detonation). If you must go farther than -20%, then set all back to 0% and reduce fuel pressure to lean your motor.
You can go lower than -20%, but *I* prefer to try to keep the S-AFC as close to 0% as possible while maintaining proper AFR. You can always add timing later by increasing your base timing. While good in principal, I usually end up in the -18% range at the upper RPM.
The S-AFC is a TRIMMING TOOL, intended to FINE TUNE the fuel curve. It's not intended to be tweaked out -40%... Once you get your fuel dialed in, you can advance your timing a bit. Detonation is not your friend.
Disclaimer - All this assumes reasonable engine condition - boost levels - fuel and supporting mods... It's best to do this on a dyno, and with a professional overseeing your work. If you blow up your engine after reading this, it still 100% your fault.
- Assume you are tuned for a 11.5:1 AFR on your wideband
My suggestion:
SAFC average = -15% | base fp = 23psi | timing = 12
Your base settings are close to neutral, with a bit more timing. The advanced timing gives more power and helps the turbo spool. Having a higher advanced base timing = more power across the whole RPM range.
Speaking generally, again. Some of the above would be skewed by other factors but I'm discussing within the circle of what you have control over. Set up your car to run well with the SAFC set to 0% across the board. Adjust your fuel pressure to get a reasonable idle and AFR. Set your timing a bit retarded to give a margin of error. Tune your fuel w/ SAFC. Then advance your timing SLOWLY. If you don't have an AFPR, then look at buying one because it should come before the SAFC.
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