I was running some numbers and I'm not sure if my math is wrong or one of my assumptions.

The Eaton M90 "redline" speed is about 14,000 rpm. Using a 3.0 pulley, the supercharger will be above redline before 6000 rpm.

Is that right?

That means the supercharger is redlining before the engine is?

If that is the case, then why run a pulley that small or smaller?