[Frank@AMS]

The T3 vs. T4 debate has been going on for a long time. You have to understand that you're working with 6 cylinders that produce a lot of exhaust flow. Utilizing the .68 T4 hot side, you would see almost no difference from a T3 housing in spool time. You would however see considerable gains in the upper RPM range. Also, with the new technology being incorporated, you are able to see improved spool time a bigger HP numbers. Billet compressor wheels are not only lighter, which helps quicken spool time, but they also have superior aerodynamic profiles that compress more air efficiently: less heat = more power. Ceramic ball-bearing center sections are more durable, have less friction, and don’t require coolant unlike the original traditional ball-bearing units.