What would happen if you raised the speed on a supercharger to get max boost at like 3K rpm and used a wastegate to keep that level of boost steady throughout the rpm band? The way I understand centrifugal superchargers is like this- if you have 10 psi boost and 10k rdeline you will have 4 psi @ 4k rpm, 5psi @ 5k, etc. What if you could have 7-8 psi steady from idle or a little above?

 

It won't work because past a certain speed, the compressor efficiency plummets. You can't arbitrarily increase the speed and get a proportional boost increase.

 

What if you could have the compressor spinning at what ever rate you wanted at all times, with a max of 8 psi, how much of an improvement would that be over the regular supercharger kits? If the the compressor spins at say 20k rpms to make 8 psi, what if the compressor hit that 20k rpms at 3k rpm engine speed, and continued to produce that same 20k throughout the rev range, would that vastly improve performance?

 

Sounds great, but how would you do that?