Originally Posted by xaamottomaax
The downward adaptation sounds as if it is an overcompensation of fuel in order to create a rich fuel mixture so knock will not occur while the MAF sensor is "catching up" to the MAP sensor or while there is a discrepency between MAP and MAF readings. Is this accurate?
I think you're getting the idea, but remember that a modded exhaust will make the MAP part of the program run lean
rather than rich.
Still not exactly sure on what's going on with it, but I think it may run lean enough during spool up to cause knock, which will cause the timing to be pulled back, and fuel to be richened up.
If knock occurs during spool up due to an unusually lean mixture the ECU will think it cannot run as much boost pressure as it realy can. So the knock system will limit the boost more than it would normally need to.
Only a possiblity, but that's kind of the gist of what I'm thinking at the moment.