Paxton has always used huge ball bearings as a form of planetary gear to step up the speed of the impeller. The impeller is what spins to create the boost. The problem with this design is that the bearing must fit very tightly so as not to slip. This means it takes lots of force to turn the blower and the tightly packed bearings are going to get very hot. As a test, I used a torque wrench to measure how much force it takes to turn a Paxton - 42 ft lbs. That means your motor has to really work to get its extra power. If it takes 60 horsepower to get 120, is it really worth it. The problem with all the heat is that the ball bearings begin to slip and you loose boost. This usually happens when you reach normal operating temperature. Paxton has tried to fix this with special fluid coolers and bearing retainers, but this is a patch at best.
