I have a UDP installed on my Max. Installation is very straight forward...as long as you have an impact wrench rated for over 250ft/lbs.
You're not exactly increasing horsepower as much as you are decreasing the rotational mass on the crank (by approximately 5lbs on the VQ30).
The belts are not the same as stock, they will be slightly shorter.
As for results, I can't put it any better than this man.
CullenJ76 wrote: RESULTS: My car feels more stable/eager at 1k-2k rpms in 1st and 2nd gear than it did before. An example is when I come to a near-complete stop, then take off in 2nd, I don't have to press down on the gas pedal nearly as much as I used to. For some reason my shifts are alot firmer than before. The weird thing that I did not expect was the gain during highway driving. It seems as if some of the dead spot(high rps) is gone in 3rd and 4th on the highway. I'm overall satisfied with the pulley and the ease of installation. Thanks again Nick.