Does aneyone know for sure if the stock ECU learns around an APEX S AFC?

During part throttle, the ECU adjusts the amount of fuel continuously based on signal from O2 sensor to maintain a preset A/F ratio, and the ECU is said to be in close loop mode. During WOT, ECU ignores the signal from O2 sensor and supply fuel based on MAP information, thus open loop mode. There are other parameters the ECU consider, such as intake temp. and engine temp., but we can ignore those when explaining the AFC.

The S-AFC works during WOT as it modifies the MAP signal to trick the ECU. During part throttle (or close loop mode), S-AFC is not as effective. Because the ECU readjust itself to retain the mapped A/F ratio based on signal from O2 sensor, thus cancelling out changes made by the S-AFC.

The answer is Yes on the MY00-01 Cars. the AFC works great on the MAF cars but the computer does learn and readjusts itself on the MAP cars

Eric

The S-AFC works during WOT as it modifies the MAP signal to trick the ECU. During part throttle (or close loop mode), S-AFC is not as effective. Because the ECU readjust itself to retain the mapped A/F ratio based on signal from O2 sensor, thus cancelling out changes made by the S-AFC.

Bravo! I couldn't have said it better myself!

-WaC
Wayne

so what u are say i will get no power out of the afc which is in a 2001 rs. is there a way to bypass that
please post reply, i need to no b/c i bought one and now its no use. is that true:( :confused:

it won't bypass it at WOT, which is all that matters.

I have a S-AFC and a Jumptronic digital A/F monitor in my car for two months now. From my observation, the ECU is doing a decent job at part throttle. I think most people use the S-AFC to compansate for mods for high throttle. Depends on what year RS, some runs lean but others ruch. I have 00' RS that seems to run rich at WOT, so I lean out from 3-5% at different rpm at high throttle. The power mods I have:
Ganz CAI
K&N filter
UD pulley
Cobb spicy CAM
MRT header/exhaust with single hi-flow CAT

so u saying
it does work, it just runs rich at high end
sill get a good amount of power, instead of that lets say , u still get power right?

The bottom line is, don't expect getting hugh power improvement by tweaking a S-AFC on a N/A car (especially 00'-01'), IMHO.

In my case, my butt dyno is not sensitive enough to notice ANY difference, maybe 2-3hp if lucky, by tweaking the S-AFC. But the light show on the S-AFC is good to impress people:lol: :lol: :lol: