High-performance street cars have one big disadvantage: They still have
to act like street cars most of the time. That means running
power-robbing accessories like power steering, air conditioning,
alternator and water pump. But there is a solution to free up
horsepower while still maintaining your street car's feature comforts:
Install a set of underdrive pulleys. Underdrive pulleys, also known as performance pulleys, drive your car's accessories at a slower rate than
stock. That means that the engine doesn't work as hard spinning the
performance pulleys and the accessories attached to them--less work
driving accessories means more work driving your wheels. The bottom line
is that underdrive pulleys can free up as much as 15 horsepower. That's
a lot of ponies for a few hundred bucks or less. Many underdrive pulley configurations are available, allowing
you to tweak the amount of underdrive built in to your pulley set, a
great feature for those of you wanting to run a full-speed alternator
but still get gains through the power steering and air conditioning
pulleys.
