WARNING:  Running an underdrive main pulley on the street is not recommended due to not being able to drive the stock alternator enough to produce enough power for the electrical systems.

If revving constantly over 4kRPM is a constant concern, as with race cars, you might want to think about running an underdrive main pulley to slow all accessories down.  The stock water pump tends to cavitate the coolant when sustaining revs over 4kRPM!  By changing to an underdrive main pulley, you reduce the chance of coolant cavitation and minimize unnecessary damage to accessories.  You can also pick up some power due to the underdrive design by reducing the amount of engine power used to push these accessories.

Racing Beat - underdrive main pulley - PN 11469
  Unorthodox Racing - underdrive main pulley - PN 0208107

Questions?  Comments?  Send mail to:  reted@fc3spro.com