Aluminum blower castings have a few undesirable traits, those being distortion,core shift,and porosity.

Bar stock has a longitudinal grain structure which is more stable and consistent property that provides greater strength and resists distortion during the machining process. The lack of porosity allows for a superior polished finish, that can't be matched by an aluminum casting.

This billet blower case combined with our proven billet bearing plates and billet front cover produces a solid supercharger that performs as well as it looks. Remember

 "It's what's on top that counts"