of performance modifications this seems to be one of the cheaper... (relatively)
however this also seems to be less common than other modifications out there. What exactly are the gains on a 5.5 gen with lighter UDP. will emissions be affected? pros? cons? should this mod be used in conjunction with something else (flywheel/clutch).

i'm asking because i'm finishing up the suspension mod's(FSTB, RSB, STS, etc) and i want to start performance mods(looking into intake, headers, ecu, udp)

 

This was one of my first engines mod. The only thing noticeable to me from this mod is that there is no lag on the engine when you use the A/C and the compressor kicks in/out. To me this was significant since we get muggy as hell in the summer and the A/C is a must in stop-n-go rush hour traffic.

Pedro

 

An UDP would really only benefit those who already have significant mods like headers or y-pipe, intake, cat-back and so on.... it does not create HP... but frees up HP by requiring the car to use less power to turn it, since its a smaller, lighter crank pulley than the stock one. In conjunction with other mods, it is said to free around 6 whp, but this is debatable. I think it'd also work pretty well if ya had a lighter clutch and flywheel... since a lighter flywheel would probably act a similar way. I THINK.

Btw, for any aftermarket UDP, you'd probably have to get different belts....

As for emissions, the UDP is a pulley, so I don't think it has anything to do with emissions..... unless you're thinking of something else....

 

I Have 2002 6sp And Noticed A Difference Rite Away Engine Spins Much Faster.best Mod Ive Done Cold Air B Pipe Jet Chip Didnt Notice Those . I Didnt Change Ps Belt Just Adjusted It I Couldnt Put On The Belt They Tell You To Use.

 

I didn't notice much. Was a b*tch to install because of the adjustments. But hey, why not...haha.

 

I noticed the UDp, It makes the rpm rev faster to redline... less weight on the crank turns faster from its lightweight perfromance. but i did feel the difference in take off and in first gear, also picks up faster..

 

i had a question, does the UDP have a senor by it? when i had a 95 maxima back in the day when i was a lil kid they said my senor was messed up with the pulley? but at the time i didnt believe him and got rid of the car

 

The UDP decreases the rotational intertia of the engine. This allows the engine to rev more quickly, most noticably in the low-end range. I noticed more pickup and quicker revs. Also, I did not notice any difference in the A/C, which is what most people worry about. If you have a huge sound system with capacitors and amps, then I don't know if you will be able to get anough power at low rpm since the alternator is not spinning as fast with the UDP. The only bad part about the UDP is that it is tough to install, but I do recommend doing it. I have a motostorm.

 

I bought the Unorthodox underdrive crank pulley and i had no problems putting it on, dont know about the others.....