by Freon » Thu Sep 07, 2006 9:18 am
Well it might be close, but as the engine volumetric efficiency changes, so does the relation. It might be 1.6 at 4500rpm but 1.5 at 6000rpm and 1.2 at 7500rpm as the cams run out. You could data log to try to find out better, but it will vary a lot on different engines, different exhausts, turbos, etc.
I'd stick to doing all your math in absolute pressure and mass air flow. The ecu does.