Yeah, the feedback from a lot of people who have installed them on their 350Zs is that they work. The hp gains I think were about 15 to 20 or something like that for all 3 pulleys available. I have seen dyno charts. If you are interested I think I still have the issue of Sport Compact Car that did a dyno run and verified the UR pulley power gains. I'd put a little more faith in their tests since they are an outside, presumably objective source. (But they probably run adds from UR in their mag so who knows, ha. I tend to think this mag is pretty fair, though.) Let me know if you are interested and I'll try to find that issue of the mag and let you know. I have a scanner but I don't know how to post scanned things in this website or I'd do that for you.

Most of the More Power gains (85% if I remember correctly) were from the weight reduction of crank pulley. The other small gains were from the under drive element and the weight reduction of the other 2 pulleys. I have heard many people say just use the crank pulley and save your money on the other 2 pulleys since the other 2 don't do that much. But with the relatively low cost, I can see that either way.

There are some long, I mean unbelievable LONG, threads over on my350Z.com in which some people say the UR pulleys upset the "harmonic balance" of the engine due to the little weighted thingy used for balancing on the stock pulleys is not present on the UR pulleys. The people that are against the UR pulleys say that over time this unbalanced situation creates vibrations that are bad for our engines. Other people give arguments just as impressive that our engines are internally balanced and the UR pulleys don't hurt a thing. Do a search over there and you can get a lot of material. This was all debated ad naueum back and forth. Like forever. I really don't know if there is a problem or not to tell the truth. I heard real good arguments both ways. I have known of a good many people that used these pulleys and never heard of any real problems that could be linked to them.

My best guess is that you're ok using them, but that's outside my area of knowledge.

The only other thing I have heard is that you may run into a problem with these UR pulleys if you run certain belt driven certrifugal superchargers. Because of the underdrive aspect, you may underdrive the supercharger as well and not get full boost. There is probably a way to compensate for that as well. Like a smaller belt spins the supercharger faster to compensate and these belts are available. But if you don't have that type supercharger, it's a non issue.

Good luck!



Post Edited (Mar 9, 1:24pm)



More Power, Thanks for your response. If you have the dyno, post it, if not not a big problem. I usually stay on my350z com but as you can see they are out for upgrade. Again, thanks for taking the time to post. BEN

ps: you here anything good or bad about the APS turbo? hahaha just kidding, I just read a huge thread with you in it that about caught fire. cheers mate,

BEN

2006 Acura TL, Black on Black, 6 speed Navi with Brembos.



I can scan it. Do you know how to post it after I have the scan as a file. Hell if you don't know how, i'll just type the jist of it for you. I am a real fast typist, but I do get too verbose at times.

As far as the aps turbos... The hell you say! Is APS coming out with turbos for our 350Zs?!? ha. Hey let's start another thread on that! Since you ASKED, he he. Hey I always tell the truth and I give as good as I get, ha. People that know me know I'm a real good person, but I don't run from fights when provoked either. Provoked first. But trolls don't really bother me. I was in athletics for years and years and in racing for years and years. And in the military. I have heard trash talking trolls forever and a day and all they every really do is demean themselves. I do a little light hearted kidding from time to time, but in good fun. Trolls on the other hand. Are trolls. ha. They are really to be pitied. They must really have problems to be like that, so it's sad really. Some trolls are kinda funny if they keep it tonque in cheek. But in this case, no. But, lets forge ahead.



If I can find the mag, I can scan or type the text, I just don't know how to post the dyno picture and other pictures. I'll see what I can do.



Post Edited (Mar 9, 2:54pm)



Cool more power. you dont have to go to all the trouble of scanning and such. Im just bored at work in the middle of nowhere, and dreaming of what else I can do to my Z. For the mean time, I want to stay NA, but later down the road, its a toss up between turbonetics and APS at the moment. BEN

edit, anyone else actually have the pulleys installed? have any feed back?

2006 Acura TL, Black on Black, 6 speed Navi with Brembos.



I'll find you the article and give you at least the text on the UR pulleys. It may be tomorrow night before I can find it but a motorhead like me has nothing more interesting than looking through his gearhead tech articles, ha.

I too have contemplated this mod. It is an easy hp upgrade and looks cool as well IMO. Costs very little. I have gotten a lot of cars eventually a lot faster by just doing little inexpensive things like this over time. No one thing dramatically pins you to the seat, but all of a sudden, I went to drag strip after several little things and was consistently running 6 or 7 tenths of a second faster. Now since a tenth of second is approximately a car length in a qtr. mile race, that can be the difference between winnning by several car lengths vs. losing a close race. On test and tune days you are running often against your buddies and people you know heads up and this is fun racing. Also in time trials you are running heads up.

I think you sound kinda like me in that tinkering with your ride is as much a hobby and fun as much as really needing a power increase. Take care.



I have them on my car. I did notice a difference, but at the same time I also had my exhaust installed. Haven't yet had the dyno done on my car. But like I said there was a considerable difference. I am pretty sure they had to change the belts as well when they did the install. My vote is to get them.

==============
DocsZ
03 Touring
DC Headers
Injen Cold Air Intake
Underdrive Pullies
Invidia True Duel Exhaust



Hey I found it. It was last year's March '04 issue of Turbo and Hi Performance magazine, not Sport Compact Car. And the peak hp was gain was 9 hp with the UR pulleys. That was 9 hp at the wheels which roughly translates to 10 to 11 hp at the engine. So my memory was off a bit, but the UR pulleys are still a good performance value. You can click on this website and the entire article including the clickable dyno chart and pictures are there. Not bad power gain for the money and every little bit helps. The pulleys look cool, too.



And son of a gun, if I didn't find another article on the Turbonetics Single Turbo for our 350z as well in Turbo and Hi Performance mag. You said that it was one of the 2 turbos you are interested in. I can't remember the name of the other turbo you like, but some people on this website swear that I am a dealer for this "other" turbo. he he. (I also own all of Nissan as well, but don't tell people on the website cause they'd gripe to me about the tire feathering issues for the lil' sports car MY company sold them, LOL. Wonder why I can't afford the twin turbos instead of the single T since I'm doing so well and all...) Enjoy:





Post Edited (Mar 9, 11:43pm)



hey i just wanted to bring something up to your attention. the dates on the dyno runs before the pullys and after are about 5-6 months. the first run was in june without the pulley and then november after the upgrade. i would think that colder weather brings better pulls....just something for you guys to think about

black '03 350z touring
20% tint, mobil 1, Whistler pro 73, custom chromed out grill, BFG KDW2's all around, JWT pop charger, MD 1/4 inch plenum spacer, 5 wire grounding kit



Anyone else with first hanf knowledge of the UR Pulley system? Comments?

2006 Acura TL, Black on Black, 6 speed Navi with Brembos.



Author: harrieyu wrote:
hey i just wanted to bring something up to your attention. the dates on the dyno runs before the pullys and after are about 5-6 months. the first run was in june without the pulley and then november after the upgrade. i would think that colder weather brings better pulls....just something for you guys to think about
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Interesting. I was reading this article in my original source - the paper version, you know the regular turbo maqazine that you buy at the news stand. And in my paper magazine version, on the dyno chart picture, they did NOT even have those dates on the dyno picture. NO dates showed up on the dyno picture at all... I see what you are saying. When I go to the weblink I gave you and click on the dyno chart, I see those dates, too.

Hmmmmn. That is strange if Turbo mag really did these dyno runs that far apart in time. As you say, IMO dyno runs need to be run back to back on the same day at the same location and dyno and even as close to the same time of day as possible. As you said. In order to make both runs at even as close to the same ambient temperature as possible. Because as we know, temperature affects the density of the air and therefore the power of the engine. It is very un like Turbo mag to make such a fundamental and elementary error such as this if that is really the case that they did. Again, in my magazine, on the dyno chart, NO dates appear. That's why I did not notice this date discrepancy, myself. Thanks for the heads up on this. Nice find.

However, I have seen other dyno runs that showed that the UR pulleys make something over 10 hp. I've known many people in the muscle car crowd that report consistently quicker qtr. mile times with the pulleys. Not by huge amounts, but noticeable. So I think the power gains are real in any case.



Post Edited (Mar 12, 6:37am)



How much did you pay for install of pulley system? Anyone? Thanks BEN

2006 Acura TL, Black on Black, 6 speed Navi with Brembos.