Forged cranks.

Impedance and reflected, intensified waves is fun Hydrazine. I used to do this for Bradley's, M1's and other hotrods and we ain't talking UR pulleys. Damn Humvee's could use this kind of help for low weight armour instead of all the crap that's going on and putting guys at risk.

By the way, 3M makes some self stick constrained layer film that's useful for many things (don't ask for all of them) including high energy mechanical dampening. Might work on a UR pulley?

http://products3.3m.com/catalog/us/e...er/output_html

Stuff works great for noise in cars too. Al will be an expert in acoustic and mechanical dampening, shock resonance and fatigue, frequency response and maybe S/N curves when this is all done.

 

I know how we can solve this argument. Lets get a stock G, make 5 dyno runs, look at the average, the high and the low. Then swap the pulley for an UR, make another 5 runs and see how the number compare.

In regards to the damage it might cause, I've had on one my Maxima for over 2 years now, many other guys have them for years with high mileage on them. If you guys are worried about what's gonna happen when you have over 200k miles on your Gs, don't worry you'll have a lot more other things to worry about.

 

Ahhhh so little you don't know about the VQ. Since you've got the stock pulley laying around, take a hard look at it next time. You'll clearly see some "dimples" on the back face. Those dimples are basically a way of balancing the pulley perfectly.

As for the 7lb pulley, I don't know what pulleys you're playing around with, but the stock 3.0/3.5 VQ pully weighs about 4.2lbs. The UR UDP weighs 1.8lbs. The Nissan 3.0L VG series (300ZX, 89-94 Maximas) pulleys were tanks and weigh about 7.5lbs. The VQ pulley is neither close in size or weight.

 

It does and many pics have been posted of pulley seperation where the outer pulley ring seperates from the inner pulley and you have two pulleys. Sorry, it's true. Very true.

 

I'd like to see these pictures man.
I'm staring at my stock pulley and it doesn't make it's way thru the entire pulley.

Please post a link before concluding anything is sad or true.

I want to see it.

Thank you

 

Could you please post a few links for us on these pics?

 

I don't know about the 3.0 vq but the one in my '04 6mt coupe weighs much more than that. Care to put your money where your mouth is? I'm starting to think you're a troll and the joke is on me.

 

Here's a link to the thread from Maxima.org with clear pics of the pulley completely seperated.

http://forums.maxima.org/showthread....t=crank+pulley

Do ya believe now?

 

Well, nice pics but that pulley is not the same as mine. It seems to have the rubber on the front side of the pulley (whereas mine is only on the rear side) and the spokes are different.

Maybe this is why the rubber doesn't go all the way through on the newer versions. I sure wouldn't want my pulley to fall apart like that at speed. The UR pulley would never do that.

 

Does the rubber ring not have to go all the way through to effectively dampen all the vibrational forces produced? Also, how does the rubber piece help dampen the forces that is produced by the crankshaft? I mean if the pulley is attached to the crankshaft, how does a piece of rubber, glued to one side of a pulley, make a difference? Minimal, that is, correct? If so, since the rotational balance of the UR pulley is better than stock, vibrations will be less, and the rotation is more or less closer to a perfect circle. Wouldn't this compenstate for not having a piece of rubber on the side of the pulley?

Yeah, I'm kinda rambling, but someone please correct what I just said, kinda confused here... haha...

 

I was wrong on one account. The G35/350Z pulley is different than the FWD 3.5 VQ. The FWD VQ crank pulley has a main pulley for the AC, alternator, and tensioner and then a small pulley welded to the back of the main pulley to drive the power steering pulley (ie the crank pulley runs two belts). On the G35/350Z, there is no small pulley on the back of the crank pulley. One single pulley drives one main accessory belt. Regardless of my misinformation for which I appologize, the G35/350Z crank pulley does have a rubber damper ring that goes thru the entire pulley. It would make no sense as to why Nissan would put it there.

FYI, here's a write up of a dyno of the 3 piece UR UDP setup on a 350Z. The three pice kit gained a whopping 2hp at 2000rpms and tailed off with 5hp at 5000rpms. For three significantly lightened pullleys, the gains were very dismal to say the least. Figure in the one single crank pulley and you're looking at 2-3hp at best.

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

Here's the dyno of a UR UDP crank pulley on a QR25DE, it gained a whopping 2hp:

http://www.nissanperformancemag.com/august04/specv/

If these things are so great, why are the gains so minimal? Making a gain 2-5hp from 2000-5000rpms isn't going to do much for your 1/4 mile because most of your accelerating is spent above 4500rpms.

 

Well, maybe I don't understand you correctly but my pulley drives 2 belts. I also propose we agree to disagree on whether the rubber goes all the way through as I am looking at the pulley right now.

Think about it this way: did your lighter weight wheels increase engine output? No. Does the UR crank increase your engine output? No. Will reductions in rotational mass increase performance? Yes. There are slight gains shown on the dyno most likely from the reduction in weight but there is a noticeable increase in what some call 'acceleration hp.'

Performance Nissan has a couple dedicated track 350z's. The drivers mention that the single most effective power mod they made was a lighter weight flywheel, which reduces rotational mass. The difference in weight is much greater than changing the pulley but the principle is the same.

 

Al, as mentioned above, inertial acceleration is better for lightened flywheel and maybe a pulley which is great for road racing. On the street....who knows? Do your own thing.

I do think people are getting confused on the fact the dampener pulley is to reduce or dampen harmonic forces on the crank that are inherent from imbalanced firing pulses for a V6 or for that matter an L6. This has nothing to do with rotating balance.

If you really want to improve perfromance, get better gears like the EVO 3.91 or use smaller diameter tires. For some reason, everyone on these forums seems wedded to 26.3" tires or bigger wheels. A change to 235-45 - 17 (25.3") will increase rear end ratio about 4% and this translates to real torque and improved performance. Some speedo error (4% or 4000 miles in 100K) but hey, beats a pulley everytime.

 

Exactly, hence the reason I'll be using my 225/50R15 BFG Drag Radials on soon to be purchased G35 when I go to the track. The tires are mounted on Mazda Millenia 15.X6 rims that weigh 11lbs. The whole combo weighs 36lbs or about 14lbs lighter than the stock combo. The overall height is a mere 23.8" which means vastly improved torque multiplication. I mounted them on my buddies 03 G35 and sure enough, they fit with about 1/8" clearance between the hub and caliper. With the auto and the short sticky tires, I'll seeing some much better gearing especially in 1st and 2nd. Plus I'll have no worries about peg-legging on the launch.

 

So let's clear the air here.
1. You don't have a G.
2. You've probably never seen the G's stock crank pulley in person
3. You think/thought the G's stock crank pulley was the same as the Maxima.

Listen, i've been reading your posts about this and that. Physics this and harmonics that.

Me and al503 were scratching our heads on that one. Both of us staring at our stock pulleys and wondering if we were in the twilight zone or something.

So basically it now comes to this. The rubber ring that you once thought went through the entire pulley was a harmonic balancer. The maxima's 4.2lb pulley, yes. The rubber ring goes through the entire pulley (in the MAXIMA). And without it, you said it would cause problems since no harmonic damper is present.

The G's does not go all the way through the pulley and you'll see it in the pics below that i have conveniently attached for you. I thought it might help becuase it seemed like you've never seen on in real life, or even a picture of one.

Don't sidetrack with smaller tires and smaller rims for better performance. The issue at hand is: WILL THE UR CRANK PULLEY SINGLEHANDEDLY CAUSE CRANKSHAFT FAILURE AND/OR PREMATURE BEARING WEAR. Don't worry about the lack of added performance from the UR pulley. I don't care about DYNO numbers you found at i-hate-UR-pulleys.com or whatnot. Here's what you do. After you get your G drive it around, get used to it. Then drive someone's G that HAS a UR pulley. The difference IS THERE. But then again, you seem to live life by reading about it. As for me, I like to live life and feel it.

It's pretty damn funny how we're talking about engine problems may arise from the use of the UR pulley. Yet you choose to counter those that are pro-UR pulley by linking us to a thread where the stock crank pulley plain gave up.

Final note: Don't talk about something unless you're pretty damn sure of it. Our stock pulley is at least 7 lbs and i've weighed it myself. The rubber ring DOES NOT, i repeat NO IT DON'T go all the way through the stock crank pulley.