Reply to "blower"

Larry, my guess is that is a Vortech J-trim or something similar mondo straight volute which has an internal step up ratio of 3.45 in the gear case. So if we assume a the flywheel pulley is in fact 14" and the blower pulley is half that at 6" you would calculate the impeller rpm with this.

14 / 6 * 3.45 * 6000rpm = 48,300 impeller rpm.

The Vortech J-trim is rated at 58,000 max impeller rpm, so actually the blower is being quite under-spun and the J-trim is a race blower which typically has larger tolerances for the impeller to grow as it heats up under high rpm which tightens the space between the housing and the scroll creating more pressure/air. The J-trim is good for 1100hp so IMO its not sized correctly for a street application which is what the rest of that motor looks like. What this means is the blower is kind of lazy on the low end vs utilizing a smaller blower that is more closely matched to the power level the car runs at which will make more boost earlier. The T, YS, YSi, and Paxton Novi 2000 would make a better candidate for a car that sees more street rpm. The car would get into boost quicker.