Scott,

A while back you said:

Grayhawk is piping up even when Tom is right.    Generally, KIAS Hg." 150   1.1 175   1.5 200   2.0 225   2.5 250   3.1 These numbers are not theoretical since this is how the pitot/static system converts ram pressure differential into indicated airspeed

Your comments were in response to my saying "theoretically possible RAM air pressure recovery."  What I meant by "theoretical" was that some of the air coming in the inlet feeds the engine itself, so all pressure can not be recovered the way a pitot tube does.

I think, at 2700 RPM a 360 cu in engine consumes 486,000 = 2700/2 * 360 cu in of air per minute.  I also think that the servo inlet is about 3" in diameter.  If true, then the incoming air is moving at about 57 Kts.  I got this by the following:

V = air volume per minute / area of inlet = 486,000 / 7.069 = 68,750 in per minute = 56.58 nm per hour.

If true, then with an inlet velocity of 200 Kts. and perfect recovery of pressure by an airbox, some of the theoretical pressure is still lost because the engine is sucking out a cylinder of air moving at about 57 Kts., so the resulting pressure has to be less than 2" Hg.  

Yes/No/maybe??  If yes, then isn't the max pressure obtainable at 200 Kts., just under 1.1" Hg.

Tom Thibault