Originally Posted by Matt @ FSP
3.25" will run the blower a bit above the maximum rated impeller speed.. So I would not run a V3 Si or T with lower than that.
Thanks for the information. I've got a V2 with a 928 impeller and some upgraded parts and been told max speed is around 62k rpm. With the impeller speed calculator says 2.9" will run about 56k but just don't know about belt slip.