I GOTTA SAY...I AM VERY IMPRESSED WITH ALL THE INFORMATION I AM GETTING FROM THIS FORUM...YOU GUYS ROCK!!!MUCH RESPECT DUE!!!ROCK ON!!! NOW, CAN ANYONE EXPLAIN WHAT THE "PULLEY SYSTEM" DOES AND WHAT THE BENEFITS OF UPGRADING IT WILL IMPROVE? ANY SUGGESTIONS WELCOME....
(-BIG NAP)

 

Underdrive pulleys run the accessories at lower rpms, taking less power from the engine to run these components, freeing up HP for use at the rear wheels.

Don't know exactly how much this is worth. I have heard claims from 2 to 15 HP, haven't seen anything on the dyno.

I don't know how bad the water pump cavitates or at what RPM is starts to cavitate at with the 7s, but for some racing applications they use a smaller pulley to reduce water pump cavitation and improve coolant circulation at higher RPMs (important since they run at high RPMs for extended durations). This probably won't apply to a street driven car.

 

are the pulleys bad. i heard that on piston motors there is a chance of throwing off the harmonic balance, but mst of that has to do with the crank. being the 7 doesnt have a crank does this apply?
kris