If anybody wants or think this might be useful I can give a pretty good How-To on installing a UDP. After install I found that the instructions in the How-To section weren't very informative on the little things. If someone will tell me how to post pics I'll do a write up.
With good instructions this can be a pretty easy mod.
By the way I definately feel gains already.

 

i was wanting to get one, and since you have one allow me to ask you a few questions.

1. when do you feel the power (rpm range) ?

2. is it noticeably more?

3. and please explain what the udp does to gain this power?

 

Just post a follow-up in the 'How To' sticky thread...

 

http://maxima.theowensfamily.com/

...in the UDP section

 

I remember seeing that How-To but couldn't find it. That's a great write-up, the only thing I might add to it, is that I used a strap wrench to hold the pulley tight while using torque wrench to tighten it. Also after I installed the pulley, I left the splash guards off and started the car. I watched the pulley in action for a few minutes. I wanted to make sure everything looked and sounded right. I also re-torqued all bolts that were loosened.
I mainly notice the difference at low end. It definately revs faster than before. I really haven't fully tested it because I want it to break in a little. Overall I am very satisfied with the performance gains.
OH, by the way. I really don't feel any difference on my stereo. The tach needle moves down a hair but it doesn't affect anything. I just don't turn it too loud when sitting at red lights.
I'm posting pics as we speak on my homepage. Check 'em out.