Re: Info on Underdrive pulleys

["Billy T." <btylaska@onramp.net>]

Underdrive pulleys replace the pulleys that drive your accessories, like
the a/c, alternator, power steering, etc.  All of these things are spun
by the serpentine belt, driven by the crank.  By putting the underdrive
pulleys on the accessories, you lessen the drag on the crank in two
ways.  First, the pulleys themselves are aluminum and lighter than
stock, therefore ruducing the mass that needs to be spun.  Also, the
pulleys are smaller in diameter, and don't spin the accessories as
fast.  Your A/C will still get cold, and your powersteering will still
function as normal, but the crank will not be slowed as much by these
items.  Think of an engine with no a/c or powersteering...  this is a
more livable solution.  V8 guys have had these things for years.  As far
as hp gains, the VR6 may gain as much as 12 hp.  This was an estimate
from a VW tech that is a friend of mine.  For 179 dollars, it would be
the cheapest most effective power upgrade for a VR6 available.  As far
as the 40 hp increase, I believe in some big V8s and high boost engines,
it is very possible.

Billy T.