Thread: Pulley Info

I had some pulleys laying around, i thought i would measure & weigh them for reference. I will work on pictures as i go.

All measurements are done on top of the inner ridges.



*Thanks to Viprdude for the UR measurements*

My personal expriences threw out the years is this, stick with the oem pullies.

Stratton.

IIRC the UR water pump is a 120mm



Yes, for street or drag racing that's fine. If you're going to track the car (not just 1/4 mile straight line :rolleyes it is recommended to throw on a larger diameter water pump pulley to delay cavitation.

I think on Unorthdox Racing sets most of the underdrive comes from the size of the crank pulley itself, which then under drives the accessory pulleys( water pump, power steering,).

When I researched this back when I was putting together a set (one seller at a time) the UR web site said the underdrive crank pulley is only about 20% smaller than stock. Undriving more than 20% resulted in almost no HP gain.

Almost all the horsepower gains come from the weight reduction of the pulleys themselves, not the amount underdrive.
They also sell light weight stock diameter crank pulleys for people who want to keep the factory speed on their accessories, but want the almost the same HP increase.

Whut?

Im assuming you thought I wasnt aware of this

I know all about, id still stick with the stock pulleys and get a top notch cooling system.

Better yet if your a real racer and not some johnny race car driver get a electric pump have way better water flow and capacity and free up some hp by loosing the belt driven pump all together..

The aft pulleys have short shoulders that keep the belts on, they do come off, its happened to me and other people I know.

Stratton.

Doom! Doom I say!

If the G Spec pulley is 120mm and the Ur pulley is 120mm why do you need to grind down the DE front cover for the G Spec water pump pulley but not for the UR water pump pulley?

UR = 110mm




Hah, same time response!!! UR is 110mm.

Some pictures

Stanza - Gspec VE - VE Stock - DE Stock