Under Drive Pulleys..and the problems they cause.

[wutang61]

I felt it was time to make a sticky about these things and end all threads about them.

Under Drive Pulleys (or commonly referred to as UDP's) are used to slow down the engines accessories. by doing so, you free up HP and TQ that would normally been lost.

The problem in doing so is...when you decrease the size of the harmonic balancer, you decrease the amount of vibrations that can be absorbed and canceled out.

This is a MAJOR problem when running the factory oil pump, the gears in these pumps are very weak. and any increases in vibrations reaching the teeth GREATLY increase the chance of failure.

This failure will most likely occur at very high RPM's, when vibrations are at the highest frequency and intensity. if oil pump failure occurs at 7,000 RPM's...your engine is TOAST.

My Recommendation: ALL people who own a Mach 1 is to STAY AWAY from them.

15hp is NOT worth the chance of jepordizing your engine.