Is there a way to extract the boost numbers coming from the MAP sensor? That'd offer a clue about what the engine's doing...

Jeff

 

Sure, the MAP sensor IS the same thing as boost ... well, absolute presssure.

 

Here is the data I have handy:

#1:
Ext Air Temp: 72.8 F
Humidity: 50%
Altitude: 52 ft
Absolute Pressure: 29.7 in-Hg
Vapor Pressure: 0.4 in-Hg

about 1 to 2 hours later:

#8
Ext Air Temp: 78.2 F
Humidity: 37 %
Altitude: 52 ft
Absolute Pressure: 29.8 in-Hg
Vapor Pressure: 0.4 in-Hg

Dyno was done inside a well ventated garage with a 4' floor fan blowing at the open bonnets.

 

Again, did you monitor the ECT and IAT for each vehicle? Those are the Engine Coolant Temperature and Intake Air Temperature, not anything relating to the ambient conditions. The reason I ask is that I have seen wild swings in numbers for the same car on the same dyno, when those temperatures vary by more than a few degrees. By stabilizing those temperatures by either allowing the car to idle or to sit with the engine off, it is possible to get remarkably repeatable output figures throughout the day.