Any Comment About RMS supercharger

[ernie]

ta,

i got it from autopower, i was really impressed with the quality and fit. i think you can find all the info about their products at ioportracing.com. hope this helps!
Ernie

[Enigma]

There is a big advantage to non-linear (centrifugal) style units. The fact that the boost comes on only at higher RPMs allows a tuner to run a higher boost for a given compression ratio than a linear (Roots or screw) unit.

Here is why. As RPMs build the engine begins to run at a lower volumetric efficiency. This is because there are limits to the amount of air that can pass through the intake and heads to fill the cylinders. This is one of the reasons that torque drops at higher revs. Because a centrifugal is non-linear it can be tuned to offset this effect without oveboosting the engine at lower RPM. It basically ramps the intake pressure to offset the intake loses thus maintaining a more constant charge pressure.

If you compare the torque graph for a NA engine with a centrifugal you will notice that they are similar at low engine RPM but diverge greatly at higher engine speeds. The centrifugal will usually be almost flat to the redline. This usually results in the HP peak occurring very close to or right at the redline.

If reducing engine compression is an option then Roots & screw types can have their advantages. But the primary reason that centrifugal are the bolt on of choice is that they require fewer internal engine modifications.