ive been reading on some forums and seeing dyno numbers that the UR crank pulley dosent gain any hp...and sometimes even loses it!!..(seen the dyno). has anyone noticed a difference in power?...personal testements? thanks

 

*PUI*

I've never heard of anyone losing power. Most that I've seen say, it's a noticeable increase. It stands to reason when you decrease the parasitic drag on the engine, it frees up power that would normally be used to drive your alternator, A/C compressor, and power steering pump.

 

Its not possible for The UR pulley system to make you lose power, unless someone seriously fdges something up on the install.
It is also impossible for the pulleys to make you gain power. All they do is free up the power by reducing parasitic loss.
I know the pulleys do not underdrive much if at all but they are significantly lighter than stock pulleys.
Less effort required from the engine to turn these pulleys = more power available to turn your wheels.
When you consider that the weight savings is only a few pounds it doesent sound possible, but consider that rotating weight, depending on the speed of rotation can be much heavier than the actual weight.
If you know allt he facts it doesnt sound even remotely likely that the UR system would lose power.

 

here is a good article about the UR pullies on the 350z. Yeas there is gain but your not going to feel 3rwhp.


http://www.nissanperformancemag.com/august03/350pulley/

 

I def noticed it on my car when we did it (done as a standalone mod). Not sure (nor did I much care) how much actual HP is gave me, but it was plain as day to see and feel that the engine reveed with much more ease than it did with the stock pulley

 

I want one that is the stock diameter only lighter.

 

I just installed mine today. Not really noticeable difference in power, but you do get slightly better response out of the engine. On another note, I notice my front left speaker stop working after the install, only to kick back in 20 miles later. Anyone have any ideas? I'll bring it up to the dealer next time im there.

 

It's probably either your flux capacitor, or your ID 10T cable.

 

No it doesnt give you power. Didnt on my car I actuallly lost power. All you guys saying it should work, because its lighter, you right but it caused a power loss on my car. I have proof that it doesnt work, do you have proof that it does? Only post personal results if you do and dont even bring up the SCC article, or somebody elses dyno

 

alot of things could of caused you to lose power other than the pulley but if it makes you feel better blame away

 

Both myself and the guy I used to go to the track with (forum member here) gained a tenth using them when I was N/A.

 

Apparently you have no idea how an engine works. If you did you would know that Its impossible to lose power by installing these pullies. The pullies have no effect on the output of the engine, but make power by being of less weight and slightley different diameter than the stock pullies.

Why dont you try and explain the reason your car supposedly lost power with the UR system? Even if you come up with something logical there are hundreds of members on this forum who are very happy with their UR pullies.

 

Share the info, the pully is on my list of N/A mods.

 

Dont question how much I know about cars. Dont say its impossible to lose power by installing pullies, I have proof that it is possible. Again Ill say you have no proof that it gives power. I dont care if 100 people like how it "feels" these are the same people that believe their exhaust gives them 15whp....and about the track times dropping, I did not gain anything at the track, actually I was averaging about .5mph slower trap speeds with it. Im not blaming, just stating whats up with MY car, if you dont like what Im posting move on. The guy asked for an opinion and I gave it, dont get your panties in a bunch.

 

It is not possible to lose power from the crank pulley. However, it is possible for the pulley to effect other things that cause you to lose power. There was one case of excessive pulley vibration/noise causing the knock sensor to detect knock and the ECU started pulling timing.

 

First good response to what Ive said in this thread. This could be the cause for MY power loss. Although I would think that it would pull timing in the upper rpm's, but I have a consistent TQ loss from 2k to 5500 rpm. I cant see the pulley causing the knock sensor to work at that low of an rpm. Anyways Im not turning this into a pulley debate, all I can say is it didnt work on my car.

 

do any of u guys know how much an install is on them?....my revs will be faster right?...and they are 200...plus a new belt?..30?..thanks