Originally posted by Fruda
And if you're wondering, the scream/howl you hear during a flyby in 109 footage you watch? That's from the air intake, much like the Corsair's whistle. It has nothing to do with the engine.
Admittedly, my knowledge of aircraft engines isnt anywhere near some on this board, but I know car engines inside and out and that howl would be attributable to forced induction, in my estimation.
Granted, the actual noise itself emits from the intake and is the result of the air rushing through it into the combustion chamber, but the supercharger is what draws the air in quickly enough to cause it.
Since boost is constant with a supercharger (relative to RPM, anyway), that whine/howl/whistle is also constant (all things being equal), as opposed to a turbocharged engine where the 'boost whine' will change in both pitch and decibel level as the turbine is spun with more or less speed (relative to exhaust pressure, in this case).
So... in short, what I'm saying is that while some of the 'whine' is attributable to the architecture of the intake, its ultimately the result of the supercharger both directly and indirectly.