With that flat, solid top air cleaner, I would guess your scoop is doing a better job of catching air and slowing the car down, than it does forcing air into the engine. Those paper 2 and 3 inch filters arent doing any favors either.
I dont think you uncovered any aerodynamic secrets by removing the hood, but getting that solid lid out of the scoop, so it's not turning you scoop into a "open parachute" mounted to the hood, is probably the gain.
Turbulent air is a mother. Many large, prop airplanes will rotate the prop blades to help stop on the runway when landing. Rotating the prop blades doesnt cause them to spin backwards, it creates such turbulent air, that it's the equivilent of adding big " discs" to the wings.
Your scoop, with your filter lid in tact is a big ol air catch.
Bet with hood on, no filter lid, base in the scoop, is probably your best combo. For mph anyways.
Speedway motors sells the least expensive, quality filter top I have found.
