Originally Posted by GS FONZy

what about it you lower your compression. Do you know why you are asking this question?

Originally Posted by jcat_GS3

dont forget the loss of efficiency with the roots blower. The centrifugal blowers (IE RMM, vortech, etc.) have a much lower coefficient of parasitic drag on them (meaning it takes less of the engine's crank hp to spin the charger) than a roots type setup. The reason for this is that a centrifugal supercharger only has a turbine wheel, similar to that of a turbo. its a direct 1:1 from the drive belt to spinning the shaft of the blower. With a roots blower, the drive belt runs on a pulley, which spins a shaft, which turns a gear, which in turn spins 2 other gears, which spin two screw shafts. You can see just by the number of stop offs how much different the two systems are.