Anyone have an underdrive pulley installed? How noticeable is the performance gains? While we're on the subject, same questions for the Y-pipe.

 

I have a SWA pulley. It was a noticable gain. I also felt a gain with all my other mods though so it could be in my head. My track results from last night are not making me happy so who knows.

 

Don't expect the underdrive pulley to make your car super fast. I would expect to add anywhere from 4-10 whp, which is hard to notice, but it does make a difference, especially if you keep installing other bolt-ons as well....All the smaller stuff adds up.

 

Yeah it did make a differnce, felt like the engine revved up quicker, especially the 1st to 2nd shift.