Mike Holmen

Mass flow is the same in and out of the charger. Just now its compressed at a higher pressure than at 14.7 psiA. The maps for the compressor side will have to be adjusted for a different inlet pressure. The typical turbocharger factory only rates mass air flow based upon ambient pressure 14.7 psiA and humity of 50%. Once you compress the gas/air to 40 or 50 psiA, the compressor maps become slightly different. The velocity (CFM) of the air decreases as the pressure increases, its called the flowing resistance. So a compressor thats rated to flow less air will beable to use more air as its become compressed. Its complicated, but that how multiple staging works. At a certain point the air become super heated and its difficult to compressor the gas/air efficently. You still have the same amount of air as you started with just now its at a higher pressure and temperature. Hotter the air, the less it wants to be compressed. It takes more work to put in than what your getting out.