What does an Underdrive pulley (UDP) actually under-drive? What accessories are affected when you install a UDP? How severe are the effects on stereo (BOSE with a single amp added- not a monster install), A/C, lights, etc.?

 

At the risk of yet again sounding like a moderator....

The search function can answer your questions.

UDP - Power steering and accessories (alternator).

 

Thank you for the basic answer. I would have searched, but the search function, as well as the "edit post" function, the "deleate PM" function, and the "send PM" function all leave me with a "Page Not Found" error message on my work computer. They all work from home, but at work I just get the error message. Last week I even got it when I made a post, now it is just in the instances specified above. Strange...

 

it's ok. The Unorthodox Racing pulley for our car is slightly smaller in diameter, and weighs a lot less. You need to get different belts for it. I doubt the power dip would be enough to merit on the system you're speaking about, because I have the BOSE in my car, and I don't have a problem with it (no amp though). I also purchased an Optima yellow-top battery in case of a drain; the deep-cycle batteries are nice as a just-in-case thing.

 

What belt is needed? How much shorter is it than the stock belt? I do not wan tto have to go buy 2 or 3 different belts to get one to fit.
Also, justmaxin96 (I think) had a squeeling problem with his UDP when he installed it. I do not know if it has gona away or not. What are your experiences with this?

Lastly, did you really notice a difference with the UDP? (anyone can chime in here- Thanks!)

 

As for the belts, I'll have to get back to ya on that. As for the power increase, I definately feel a harder pull at lower rpms (keeps me happy). Also, I had a belt squealing prob once but found out it was because I didn't tighten the belts enough. Hope this answers your questions (post later tonight with the belt sizes).

 

PLEASE use the search for this stuff. See Cheston's installation information for belt sizes ( www.maximadriver.com ), or do a search. I did not dyno before/after. There are a MILLION threads on the UDP. People who did track runs had some gains, but there are plenty of people who say it does nothing.

 

Please do not get p!$$ed at me for saying this, because I appreciate your help, but I know how to search. Did you not read my post above (copied below), after the first time you told me to search?
THE SEARCH FUNCTION RESULTS IN AN ERROR MESSAGE. In your reply to MY reply, you even acknowleged that I could not search.

 

Moments of Inertia:
Icm = MR^2

The UDP replaces the crank pulley on our car. One belt drives the Accessories (alternator/AC Compressor) and the other belt drives the power steering pump. From what I recall only the accessory belt is underdriven and not much at that. I live in TX and notice no decrease in AC performance. I also have the Bose and a 300W JL Audio 12W0 and have had no battery/alternator problems. The way the pulley frees up power is by reducing the energy wasted in turning the pulley. If you make the radius smaller and/pr make the pulley weigh less it's easier to turn (the same holds true for slowing down).

I felt it made a difference and by straight physics it works
-hype

 

Good call Hype (I'm a 3rd physics major ). Anyway, the belt sizes are K-060408 and K-040292 if you didn't already find them. Good luck on the install and don't forget to tighten those puppies up.

 

While we're speaking about belts I bought 3:

Alternator & Water Pump
1995-02 Gates # K060408

Power Steering
1995-02 Gates # K040292
If this one does not fit then try: Gates # K040300

I tried to fit the K040292 and there was NO way it would fit. I ran the adjuster all the way down and it was still too tight to fit on. I used the K040300 with no problems though
-hype

 

Thanks, guys. I appreciate all of the help. I need to talk to my network admin about the error messages. It really ****es me off...