Notice on the DSMlink Screen capture above, the user is at these
RPM = 5682
Actual Boost = 21.7 PSI
BoostEst = 34.3 PSI
MAFraw = 2841 Hz
We've got a ton of calibrating to do. This particular log shows a good amount of boost being pushed
through the motor. What I like about this log is that boost is very stable, so you can almost see the VE curve in the BoostEst
curve. Notice how BoostEst peaks and then falls as the motor gets closer and closer to redline.
The airflow slider we are most concerned about is the 2400+Hz slider, because at 5500 we are
already way past 2400Hz. Now it is time to plug the values in the equation.
((21.7 + 14.7) / (34.2 + 14.7)) - 1 = -25.5%
According to the calculation, we need to bring down the 2400Hz slider down 25% from where it is
currently at. A drastic compensation like this usually will be caused by a boost leak after the GMAF.
NOTE : If for some reason you need to pull more than the DSMlink allowed 20% away
from the 2400Hz slider, you may need to use the WOT Translator knob and take addition airflow away.
Now what about the other airflow sliders like 1200, 1600 and 2000Hz? You can take the easy way out
and just gradually blend them in with the 2400Hz slider. Or you can do it the long and more accurate way.
The way to do this is to lower down the boost until MAFraw drops low enough that you are at 2000Hz
while you pass through 5000-5500 under WOT conditions. Use the airflow equation for the 2000Hz slider. Then lower the boost
again until MAFraw is 1600Hz as you pass through 5000-5500 under WOT conditions. Repeat again for the 1200Hz slider.
NOTE : GMAF calibration and Intake Air Temperature : The GMAF assumes the intake
temps are in the 79-81F range. Any difference from this temp and there will be a change in BoostEst.
For every +10F degree change in intake temps, BoostEst will drop approximately
1.0 PSI. (Info taken from Rick E. Martin posts in DSMlink forum)