Thats a pretty ridiculous claim.

You'll never be able to make 23psi of boost with an m90 on this motor. You would have to spin the blower so fast and so far out of its efficiency range the heat generated would cause so much know that it would destroy your engine.

Anyways, how would a lighter rotor pack increase psi in anyway? If anything it would decrease the parasitic draw from the engine spinning the rotors