sh*tbox what you say is true. A centrifugal SC will be more efficient and thus have more power potential vs a rootes type SC. But an exhaust driven centrifugal blower, a turbocharger, will make more power than either because most of the power to drive the compressor is coming from the exhaust gas not off the crankshaft. If both types of engine are making the same IMEP the turbo engine will make more power.