Quote:
Originally Posted by nelsmar
The ecu doesn't need a wideband to verify its AFR targets. The AFR traget is created based off the maf calibration and other tables combined. The car in open loop can run completely with out a af sensor. The car does not need to know if it is more than say... 1AFR off for adjusting fuel trims, so there is simply no reason to spend the time calibrating it from the factory as it literally does nothing for the ecu. We however are using this sensor to verify our target AFR and as it is only calibrated from the factory for closer to stoich levels... we need to extend this to see further.
The region in which you would be in closed loop with the factory tune is pretty much all 12+AFR. Once you dip into areas in the 11's the car should be in open loop on the factory tune. Open up the fuel table and you will see what i am talking about.
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to be accurate, only 14.7:1 can ever be targeted in closed loop, the logic doesn't work any other way. the values in the closed loop section of the map that *arent* 14.7:1 actually arent targets, they're there to generate trims, but that's another topic for another day.
suffice to say that the ecu can only truly target 14.7:1 in closed loop, even if it acts like it isn't sometimes.