Identifying aftermarket pulleys
 

I just bought a 2010 370Z from a dealership which has some work done; full FI exhaust, LED's, and some other aftermarket products. I'm trying to figure out if the previous owner bought UpRev and/or replaced the stock pulley with either a lightweight or an underdrive. Is there anyway I can tell if I have UpRev or pulleys just from looking? My voltage meter is always right at 14 or a little above... I know this isn't much help.

All of the pulleys look to be black EXCEPT for the crank pulley which looks to be polished or aluminum of some sort. Here are the best pic's I could get....

Thanks!

You'll get a better angle from under the car, just remove the plastic trim piece.

It might just be a lightweight pulley if it's just the 1.

Yeah - but can't you buy just an underdrive pulley? Right? Isn't that what people do, buy an underdrive pulley and get a Gates belt?

If you just get an Underdrive pulley, the system will be slightly off. That's why NST makes the Overdrive Alternator pulley to balance everything out. So you still run @ 14v.

Will an underdrive produce more noticeable power gains than a lightweight? I have an underdrive from Stillen that just came yesterday - I was just waiting on the Gates Belt. I think it's obvious that I have an aftermarket pulley - not to mention my car runs pretty well - with the full exhaust. I mean, I light stock Z's up.

Both the lightweight, and the underdriven pulleys are doing the same thing. Less rotational mass = faster through the RPM band. Different methods of the same goal. Even though your gains will most noticeably be seen from your being tuned for these mods.

Don't mention that part. :tiphat:

Looks like Stillen's pulley, but I couldn't tell you if it was just lightweight or also underdriven. The Underdriven one is *also* lightweight, with the added benefit of reducing parasitic drag from the A/C, power steering, etc. But then again it underdrives the alternator, hence the whole overdrive alternator pulley thing from NST. You can run on just an underdriven crank though, especially if you've got a healthy full sized battery in the stock location.