Originally Posted by
barum
From what I've been able to gather the formula could be something like:
DynamicAirflow[n] = DynamicAirflowBaseGain x DynamicAirflow[n-1] + DynamicAirflowCurrentGain x MassAirflow[n] + DynamicAirflowOldGain x MassAirflow[n-1] + DynamicAirflowCorrectedGain x MAPTPSCorrection[n]
MAPTPSCorrection[n] = DynamicAirflowMAPCurrentGain x MAP[n] + DynamicAirflowMAPOldGain x MAP[n-1] + DynamicAirflowMAPOld2Gain x MAP[n-2] + DynamicAirflowTPSCurrentGain x TPS[n] + DynamicAirflowTPSOldGain x TPS[n-1] + DynamicAirflowTPSOld2Gain x TPS[n-2]
In above the sum of
- MAP gains seems always be zero or nearly zero
- TPS gains seems always be zero or nearly zero
- BaseGain, CurrentGain and OldGain must always be 1 IF MAPTPSCorrection function has been zeroed out => you can play with differently weighted average of the two most recent MAF readings and previous DynamicAirflow
I tried values from LS9 and ended up having Dynamic Airflow at permanently higher level than MAF reading, hence the above "rule".
I'll have to check whether the car was in hybrid mode (MAF + VE) during that (accidental) test, but earlier when in pure MAF mode it didn't seem to respond to these changes at all.
However depending on the application, there are quite a few differences between them
- there are areas in LS7 where MAP + TPS gains has been zeroed (cells 2 & 3 which activate when leaving from idle)
- LS9 seems to disable all MAP + TPS gains BUT values of BaseGain, CurrentGain, OldGain don't sum up to 1, also CorrectedGain is set differently (the function at the top this post might be different or not correct at all)
- LS2 (E40) seems to disable either MAP + TPS or only MAP on some cells
- LS3 seems to use only BaseGain and CurrentGain, OldGain is zeroed out as are MAP and TPS gains
More testing is needed to see how they work (or do they work at all) in practice.
According my experiences the "raw" MAF seems to be much smoother than DynAir especially when engine is showing bucking or "misfire like" tendencies using OEM coefficients with moderate (18 deg overlap @ 0.05" lift) cams.