[Walt Fricke]

Well, Porsche's experience was not good, though no doubt part of that was due to the thermal problems the anti-smog stuff caused the 2.7s.

And would it not make sense to use the drive ratio they did, assuming you want the cooling they thought was needed for the less powerful 2.7s? Unless this is a full out race motor where you are scrimping for that extra one horsepower?

You can find the CFM figures for the various stock configurations. I don't know if you could extrapolate from those for the 5 bladers down to what turning it at a slower percentage of the 5 blade speed would give you in CFM, for a comparison with what the 2.4S had as stock.

Is fan flow directly proportional to fan RPM, at least at some range of RPMs before cavitation and other stuff sets in? Or does the inertia of air molecules mean that there is a curve which tends toward flattening as blade speed increases? As the power to turn it increases (exponentially, I assume, like the car's body as its speed increases)?