I know the Playboy Grand Am car, if you are talking strictly Z's, runs the UR pulley (a blue one..old style). I can't say about others as I have not seen others up close, but when in the pits last year, it was the first thing I looked for.

 

yeah, pretty much straight forward indeed. i've had UR pulley(underdrive) on my 03 since 04, there is definitely a noticeable gain in throttle response. It put a smile on my face after the install. You will need a 22" breaker bar to loosen the main crank bolt.

 

i have a 13 second 2002 max, i know pretty well what im looking at, considering every engine mod ive done was done myself

 

Okay, point taken. How then does someone incorrectly install an aftermarket pulley without having the entire motor fail in the process? You alluded that I had misinstalled my UR UDP on my old VQ30 hence the reason I saw no performance benefit. I'd like to know how that's possible seeing that the pulley slides on only way, I replaced the crank seal, the timing ring was fine, and the belts were set to the correct deflection. I had that pulley on for nearly 2 years if I remember correctly. How could of my VQ lasted over 20K miles, 40 1/4 mile passes, and 8 dynos with a misinstalled pulley?

 

They are a stock diameter with additional machining done to make them lighter. They use stock sized belts as a result.

 

just the absolute smallest little imperfection of the mounting surface (grime, dirt) will cause a slight vibration that wont ruin anything but would be annoying

 

Don't agree at all. Plus I don't know you wouldn't know if you had some sort of significant debris in there causing a problem. The pulley can only go on one way because of the key on the crank. It can't go in at an angle. If you had something like a peice of sand between the pulley and seal, the sand would simply get mashed into the rubber seal. No real big deal, but you'd have to be a damn fool to be assembling a motor with debris-laden parts

 

for the vibration that you had (explained), you had to either have a bad pulley or something on the mounting surface. a correctly formed and correctly installed pulley will not shake like that

 

It couldn't have been from the fact that the UR UDP didn't have a damper

 

It is commonly known that he is against about every damn single mod on the G35 or Z that has been proven in the past to work but since he doesn't own one or never has he rather just argue to no end with no experience behind his belt or facts that they don't work. Everyone is sick of his bickering on the G forums, and now he is here.

 

Technically Daveb is right in theory. The stock pulley is specifically designed to dampen frequencies that can harm the crank. His explanations are accurate; again in theory.

However, the fact remains that plenty of people have properly installed lightweight pulleys with proper pressed steel inserts without breaking their crank or blowing up their engine for long periods of time. This fact is even highlighted by Dave, furthering his credibility on the matter imo.

So do you believe the theory or the reality of its use?

I think if you are racing or boosted, fluidampr is a must, if you are NA and DD then I guess it's a toss up. Believe what you want to believe. But I think there is a definite track record of properly constructed lightweight pulleys for the vq35 never destroying any cranks or engines. As far as advantages are concerned, there's no doubt there is a gain in throttle response, but as far as actual gains or helping a 1/4 mile time or the like, well that's up in the air imo--I haven't seen proven results on this board in the form of dynos or lowered 1/4 mile times--but that didn't stop me from buying a set.

I believe Daveb disputes the claimed gains and advantages of the lightweight pulleys, especially in light of the possible risks of not having any sort of dampening properties in a lightweight crank pulley. There's nothing wrong with thinking that way. He's entitled to his opinion.

I guess I just chose to go ahead and run the lightweight, but stock diameter UR pulleys-no problems as of yet. But the fluidampr is going on if/when I go boost.

 

after installing these.. underneath the hood motor seems to be alot louder.. is this normal?

 

Installing what? UDP or LWP?

 

yes, you'll hear the accessories a bit more with an aftermarket pulley, with either a std diameter or under driven one

 

So I can look forward to added cabin noise ...hehe
Thank you.

 

truth be told its not noticeable at all unless you are standing over the engine bay with the hood up

 

Cool, I can live with that..
I will most likely get the crew from AMS to install my LWP's, so if its to noisey I will just b|tch them out...., haha



Vuk, I KEED!

 

LWP.

and yea lke Z1 said only notice it when youre standing outside infront of the hood.

 

any one know if they fit a HR?

 

there are no pulley sets out yet for the HR