Thanks for the responses. I will tell you that I have already leaned in favor of not installing the pulley based on this thread....I agree a 5hp gain at higher RPMs is not worth the risk.

BUT, what I was looking for from y'all was a response/feedback to the mechanical enginnering aspect of Stillen's response, not necessarily if I should do it or not. IS it reasonable that the stock pulley is NOT completely 100% balanced and that is the reason for the tiny rubber ring? Does a pulley that is supposedly completely balanced not require a formal ring dampener or do the belts if properly installed and adjusted dampen vibrations enough like the UR....

Again, I know Stillen has a vested economic interest in aftermarket parts sales and have a reputation for making bucks on their seemingly overpriced products but I have found they are somewhat helpful and can be objective (not always) about some of the questions I had for them.

BTW, Stillen does not have a restocking fee, you just have to pay for shipping the sutff back to them, which is pretty normal for other retailers huh?

Anyway, just want to understand more of the physics of aluminum vs. stock material, balanced vs. not-so-perfect balance, belt dampening vs. tiny rubber ring dampening, etc.

Thanks again......
docron1

 

No. Engineers design parts to nominal tolerances for a reason. It is too easy to design the part right the first time. There are several ways to fabricate/design a pulley. They can be forged (strong but expensive), they can be "hogged out" or machined from a billet (not as strong, but capable of holding tighter tolerances if desired), they can be cast (cheaper and easier to make with hard tooling, but not as strong as the other two methods). The casting process yields the "loosest" tolerances or the most "variance" of the 3 processes mentioned above. Also, the casting and forgings need to be machined, they just have a "near net formed" part with many fewer machining operations. There are other ways to go about making a pulley, but the 3 ways mentioned above are the way MOST of the steel/aluminum parts on your car are made.

Nissan doesn't sell you a car that is intentionally designed improperly, at worst they would sell you a car that is not put together properly. The quality control on items that are connected to the engine are critical to their bottom line. If they made bad hardware, just think how much money that they'd loose as a result of warranty and recall items. It just doesn't make any sense.

300bhp??? We'll see... 5-22-2004

 

al503,
My scenario was depicting a situation where the pulley had already done its damage, been removed, then the car (without the pulley on it anymore) would be sold to an unsuspecting person who may have wrecked the car or taken in for repair and no one ever knew a pulley was even an issue.

The thrust of my point was that "no one has complained about a pulley yet" doesn't prove or disprove anything. I do get your drift however. And it's a good point, but I've stated before this is a long term problem, not a short term rattle or plastic plenum cracking because of over torque. It may be a slow insidious breakdown that slides under the owners radar. It may not be. I don't know. I'm the first to admit that there is a low probability of breakdown here. That's why I qualify my point with "risk/reward category". 5 HP, $300, might need new bearings (1% chance let's say) just doesn't cut it for me. However, 5HP, $800, might need another Shimm put in my exhaust (30% chance), that's a different story. I would do the latter, but not the former....at any percentage.

If I had a problem with a pulley I would shout it at the top of a mountain. But if I bought a 5 year old used car and had a bearing problem and the guy that sold it had already changed it back to stock, how would I know to complain? That's the problem with the vendors' arguments and the whole "well no one complained before" argument. You don't know to complain about something you were never aware of, and many of these vendors haven't even been around long enough to see the possible effects of these mods.

2004.5 Coupe/5AT/Ivory/Everything but chin spoiler/Z Tube-Popcharger/Crawford V5 Plenum on the way

 

Thanks neff, -fish....

Return shipment back to Stillen underway and refund........

hmmmm....what can I do with the refunded $250 for my G???? Crap....my wife's birthday is coming up....oh well. lol

Thanks again,
docron1

 

hey cat, I understand your previous post much better now. You're point is understood and well-taken.

 

No worries, right back at ya.

2004.5 Coupe/5AT/Ivory/Everything but chin spoiler/Z Tube-Popcharger/Crawford V5 Plenum on the way

 

Some people have said that the OEM pully is balanced on the engine. If that were true, it wouldn't matter if the pulley itself were unbalanced. It would be a problem if you replaced it with a truly balanced pulley.

I find it hard to believe that the OEM pulley is balanced on the engine for whatever reason. And I don't think the rubber has anything to do with harmonic or any other kind of balancing.

But I will change my mind in a second if I had more FACTS.

Easy way to check balance, put it on a level surface and see if it rolls. Come on everyone take off your pulleys now to check this scientifically!


2004 G35C 6MT Black. What Honey? I don't know where they came from. I came home and it was like that...

 

Thought I would offer a little history......

Shawn approached me about selling a crank pulley for the VG30DETT (Twin-Turbo 300ZX) back in 1996. I think this was one of his first designs. I didn't actually jump on the pulley bandwagon until I had my customers begging me for them by 1999.

It's been 5+ years since then, and I'm yet to have a single issue that I'm aware of. This would literally be thousands of pulleys later.

Yes, I make money on these sales. What's the borometer for me to keep suggesting this product? You are. Not one complaint.

Best bang for the buck horsepower mod available in my opinion.

Turbo Magazine seems to think so, as well.....

http://www.turbomagazine.com/tech/0403tur_350z/

Adam Out!:-))



Adam Hume
Steve Millen Sportcars / Stillen
800-576-2131 Ext.#138

 

So meeting today with Jackson Stewart from Unitech & Stewart Racing, we not only talked about new product from the race team and new things the race cars will be sporting but also....

You guessed it....

UR Crank Pulleys...

Lets look at the stock pulley...

It does Not have a harmonic Dampener. It is NOT Balanced. It is made of a cast iron... Those of You who know, when metals are poured into a casting the different cooling speeds in certain sections of the cast as well as any inconsistency's in the material can cause density inconsistency's as well as weight differences.

Lets look at the UR Crank Pulley's...

They are FORGED out of a Solid piece of Billet Aluminum. You cant get much more balanced than that. The material's that these pulley's are forged out of is the same consistency and density tthought the material. If it is cut perfectly symmetrical (which they are in the forging process) then they are going to be perfectly balanced. So, actually running the stock pulley, even though it doesn't matter your stock pulley is NOT BALANCED! So if anything. The stock pulley will cause all the problems before the UR Pulley would.

Good reading on UR's web site at this link...

http://unorthodoxracing.com/faq_pulleys.html

oh yeah... all pulley colors are in stock again on www.mynismo.com



Jason
AIM: PerformanceNISMO
Yahoo: MyNISMOParts
http://www.performancenissanparts.com<P ID="edit"><FONT class="small"><EM>Edited by gsedanman on 05/12/04 05:11 PM.</EM></FONT></P>

 

I'd purport that the UR pulley extends (thorertically and all else equal) the life of the VQ. Less weight on crankshaft and better balancing.

Perhaps

2003.5 DP 5AT Sedan (E-thing but Nav)
14.2 @ 97.18
Injen CAI
10 Wire Hyper-Ground
Crawford Plenum (V4)
UR Crank Pulley
Polk ex-3500 Tweeter Upgrade/Shock Sensor/H-Liner Under Hood

 

Jason, is the crank pulley (UR or otherwise) Nismo endorsed, sanctioned, or supported in any way? The fact that it's sold on a Nismo/Nissan branded web site implies that it may be.

2004.5 Coupe/5AT/Ivory/Everything but chin spoiler/Z Tube-Popcharger/Crawford V5 Plenum on the way

 

the crank pulley for the 350z is not a nismo product. it may become but who knows. i know of a few products nismo is about to release as a product from them. but.

what alot of people dont understand is...

NISMO and Nissan Motor Sports are TOTALLY DIFFERENT!

NISMO is where you have the S-Tune and R-Tune products that are avaialble through NISSAN Dealers standard Parts System. They can be ordered from any Nissan dealer just like any Nissan factory part. S-Tune has warrenty / R-Tune does not. (short explination of this)

Nissan Motor Sports - is the RACE division of NISSAN where the parts are approved for a long list of race class divisions. Those products are approved though many different test processes just like our seat belts are to be DOT approved. I am getting a whole bunch of new Nissan Motor Sports parts that will not be seen by NISMO america but only for the race division. This is where you get Pistons / Rods / Cranks.

Jason
AIM: PerformanceNISMO
Yahoo: MyNISMOParts
http://www.performancenissanparts.com