View Full Version : OD and UD pulleys

01-30-2006, 09:14 PM
what are the gains/losses of using these my dad says using an od pulley on the sc is just a gaurantee to blow a h/g but if i just replaced them and tryed to prot the exhaust manifolds how much hp would i gain with a 10-15% u/d pulley for the SC and what about the other ones? just wondering sorry if its a stupid post its just the SC is my 1st car and im trying to take some more knowledge of them in Thanks Tony

Kurt K
01-30-2006, 11:51 PM
The search function is your friend.

Anyway, you'll see varying opinions, but the majority of people that install UD pulleys do feel the gains. However, I don't know if anyone has ever dyno proven gains.

As for the SC OD, if you still have stock exhaust, I wouldn't do more than 5% OD. With that said, I ran a 10% OD pulley on my stock exhaust years ago (before this site) without any issues. But I still don't recommend it when people ask.

01-31-2006, 07:07 PM
stock exhaust as in manifolds? or system from catyletic converter and on

01-31-2006, 09:06 PM
the exhaust system from the manifolds back, the cats, resonator, and all the bends in the early exhaust are some real flow setbacks