I just ordered my UR pulley set today. Butt dyno posts I've read predict more torque at lower RPMs. Would you mind sharing what you think I can expect? The only other mod I'll have is the CAI, but from what I understand that brings on more power in the midrange.

Thanks

 

I've only heard good things from Z owners on this subject. Had a UDP on my Max too, and it worked great.

 

That's it... I've decided to upgrade my pulley too.

 

I installed a UR crank pulley a few months ago and so far this mod has given me the most noticible change to the performance of my car..........the engine revs so much faster (the first time you drive the car after installation you will look like this ) I have no negatives so far....my aftermarket stereo works fine (running 2 amps, about 900 peak watts), my ac works fine (90+ here in houston), no problems with engine temperature (i drive the car in a spirited fashion most of the time), and no additional vibration. I know the harmonics of the crank probably can not be felt and my warrenty is in question.........i did a lot of reading on this subject (there is a BUNCH of threads and info. on the net) but for me this mod has been worth it so far........i also like this mod cause it is a DIY (important for me) hope this helps

 

What's funny to me about the great pulley debate (and they happen on every board for every car) is that some people are so afraid of taking a few oz's off the one end of the crank, but wouldn't have any issues with taking a bunch of oz's of the other end of the crank with the flywheel on it....

 

Why doesn't anyone make a lightened but not under-driven pully? I emailed UR and they ignored me. I would think that it would be a huge seller, seeing as how most of the people who decide to not go with this mod do so because they don't want to take a risk on damaging their accessories. You get 80% of the gain but with more peace of mind.

 

Where have you been???

They DO!!!! $170.00.....nice piece.

http://www.kjrperformance.com/

 

You won't get anymore piece of mind from a lighter same sized pulley. Underdriving the accesories makes thier useful lives longer. The accessories don't seem to mind and there seems to be no detriment to the them. The risks are with not having the rubber dampner that is built into the stock pulley. The accessory's/ belts supposedly create vibration that cause crank wear and vibrations that are intolerable after time. Only time will tell but no problems here.

 

Hmm... Well, look at that... Never heard of them though. Thanks for the link.

 

I was reading thru the old posts on this topic from last year. Very touchy subject.

However, Id like to know how the pulleys have done over the past year.

Sixfive, youve had yours for a long time now, whats your impression since you installed it and how many miles have you put on the car since then?

 

I've put about 10K on since UR pulley installation. Impressions are great. It's a small increase in power, the motor revs quicker and it's one of a few minor additions that in sum make my car much quicker than stock. If you want bang for buck, the spacer you already have it great I hear. The pulley changes the around town driving experience quite a bit and there is less turbo type lag at 2000-3000 rpm. Acceleration is point and shoot rather than point, wait, shoot.

 

There's a lot more rotational weight on the driveline side of the motor. A torque converter and/or flywheel act has dampers and weigh 30+ lbs. Shedding a few pounds here and there isn't a huge deal.

Like the SixFive said, the issue with UDPs isn't the weight, it's the fact that the OEM crank damper has been removed. Will your VQ's crank fail because of a UDP. I highly doubt it and I've never read one case of a VQ failing because of the UDP. I don't own a UDP for my VQ35 because I already had one on my VQ30 Maxima 5MT and it didn't make me a lick quicker or faster in the 1/4 mile. The motor "felt" more responsive, but when put to the real test of 40 1/4 mile passes, it wasn't the case. The only thing it added to my VQ was some engine vibration, stained upper rpm noise, and poor low rpm driveability.

 

I like being "THE" SixFive. LOL

 

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