Topgunz - air to air upgrade

Originally Posted by BOLIO 671

Yes Si Trim Si Upgrade and Si Impeller are all the same thing. You can replace the impeller urself but it wont be warrantied. Most people turn it into Vortechfl for the warranty and also so they can get their bearings upgraded...which is also recommended. The bearings that we have are designed for SCi....changing the impeller will will increase boost thus working the blower harder.

928 Motorports also does upgrades but they are pricier.