85 6 port with IDA style intake and fueling. Its somewhere between stock and a street port due to the rules the engine was built for.

So Ive been futzing around with my idle and no load section of my maps and have found my engine likes high 10 low 11 afr's. Its possible my wideband is telling lies but I dont have anything to calibrate it against.

Anyways the range of AFR is about the same through the no load range when tuning. I can set the throttle to any rpm, tune the mixture for the highest rpm in that range and it comes out to about the same AFR range.

Im using the NGK wideband/controller, its been a few weeks since I took it out to calibrate, Ill have to do that this weekend and see if thats all it is.


Any thoughts?

 

you should ignore the AFR at idle, and just set it where it runs the best.

over about 15% throttle and or 1100rpm, the factory ecu is in closed loop @14.7:1.

over about 3200rpm and or 50% load the ecu is in open loop, and the AFR starts out around 12.5 and then either stays around there or goes richer, depending on the year

 

anyone else tuning N/A cars with aftermarket an ecu?
Seems like its something mostly the turbo folks do.