I have researched UD's and didn't come up with much , so i figured i could get a quick answer from you guys... When people upgrade the Underdrive Pulleys for upgraded performance, do you get noticeable gains?? Maybe 10rwhp for 2-300$, hell yeah thats badass... Would this link + a belt be all i need?? How hard is the installation??

http://www.lmpracing.com/24540/4.html

 

That's what you need if you're putting it on a C5 vette. The install really sucks on vettes too b/c you have to pull the steering rack (sits right in front of the pulley). Most people just wait and do the pulley at the same time as a cam since you have to pull all that crap off anyways to get your timing cover off. Too bad they didn't make our timing covers 2-piece from the factory!

 

Ahh thats what i thought bro, thanks for the reply man. But you know a little thing like that isn't going to hold me back, even for MAYBE 12hp +1-2 more mpgs..hehe (More replies come on in!) What do you guys mean when you say FAST 90/90???

 

udp helps you run your ac also while you racing with the udp when you turn on your ac you won't notice your rpm fall from lost of power I'd say a good investment.

 

It's a good mod, but it is a pain to install. So I don't know that I would do just the pulley if I was going to do a cam later. You may see 10 HP on the dyno, not sure. But it also helps the motor build RPM's faster which you won't really see on a dyno, so you should see slightly better gains at the track than you will on a dyno.

Fast 90/90 is a larger intake and throttle body. Good mod but expensive and IMO not worth the investment until you do headers/cam and possibly heads.

 

Dave is you z28 an a4 I see you have 3.42 how much of a gain did you pick up with the upgrade?

 

It is an A4, with a TCI 3500 stall. I haven't had it to the track since I put the gears in so I couldn't say. And I did the gears about the same time as heads/cam/headers/intake. I didn't think the 2.73's would be a good match for the mods. They are much funner on the street compared to the 2.73's tho. I think it's a good all around gear for an A4. 3.73's would have been a good way to go also, there really isn't much difference in them. I just wanted to keep it as streetable as possible and still capable of 80 mph road trips.

 

I gained 12rwhp & 12rwtq with the SLP pully and had no ill effects from it. Great mod for the $.