Iam wrong, the answer came to me, the inlet is about 750 cfm, but the engine is 339 cfm at a boosted - higher density of air-.

Duuugh! I missed that one, thanks for the info and correction.

yes the cfm at boost is about 339. However the denser air has more mass and thus friction as the air is THICKER.

In the end the dirt causes some measurable pressure loss. Woody

Happy hour does improve your mind. . . .