Great mod for the $. 
Underdrive Pulley
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Underdrive Pulley I have researched UD's and didn't come up with much 
, so i figured i could get a quick answer from you guys... When people upgrade the Underdrive Pulleys for upgraded performance, do you get noticeable gains?? Maybe 10rwhp for 2-300$, 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
, 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
Last edited by PassionateZ; Jun 21, 2008 at 08:37 AM.
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!
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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???
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From: Lexington, KY
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.
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.
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.
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.
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Joined: Feb 2004
Posts: 1,259
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From: Lexington, KY
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.
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