Originally Posted by Franc Rauscher

Yep, I'm going with Woody on this one.

Whether compressed air gets to the throttle body on not, the induced higher pressure at the inlet has to help overcome the fluid friction of the inlet tubing.

Even the 3.0" CAI tubes have friction on the walls. That is resistance. That is turbulence. That spells lower air pressure, ie vacuum; ie lower density air at the TB. Vacuum creates turbulence because of eddys. Added pressure at the head reduces vacuum induced turbulence. There is higher pressure in front of the radiator and that is absolutely ram air.

The piston engine is nothing more than a compressor with a spark plug. It takes HP to draw the air into the cylinder as the piston moves away from the head. Any resistance to that movement uses HP. Lower that resistance, cancel that loss. This is why it takes a 10 HP compressor to do a 5 HP mechanical movement.

There is also higher pressure at the base of the windscreen although less volume. This is particularly true with the higher aspect windscreens of cars from the fifties and sixties. Early sixties Chevy had a kit for it. It improved performance on carburated cars. I put one on my 56 Pontiac and had to open the highspeed fuel jets to keep the mixture rich. That suggests more available air.
Buttmeter said I got more HP at the higher speeds.
So did my street racing tickets.
It also made my wipers feeble.
roadster with a stick