Stillen Crank Pulley
#76
Pulleys are not really going to give measurable gains in power but what you will notice is faster, effortless revs. It will be a feel thing. This is the same thing with flywheels and other mods that decrease mechanical effort such as roller cams, lighter valves, lighter pistons and the like. The engine will feel more lively and crisp and quicker to respond. The stock pulley is 8lbs and these aftermarket pulleys are 1.5-2lbs, a huge savings in rotational mass. Think of it like how lighter unsprung weight improves handling feel because the wheels and tires are controlled better.
#77
Premier Member
iTrader: (17)
Install was just short of 2 shop hours, it cost me 130 to have it done. The mechanic said it was quite a bitch to get the stock pulley off, but afte that it was a breeze. I've seen on other cars double digit hp gains with pulleys, so they do offer some hp on different set-ups, not just revs. I'm willing to bet I see an increase, it's not just a feel thing, the car is noticably faster compared to my friends cars, i can't believe its just from the weight reduction. I weighed my stock pulley and it came in at 8.8 lbs, UR pulley was 1.5.
#78
I guess it would depend on the type of dyno. The old rule of horsepower production is move more air to get more power. Pulleys don’t move more air but if the dyno can recognize and measure the energy that was used to spin the part (pulley, flywheel or whatever) you could see a gain. The gist of my post was more power is not the primary reason to lighten rotational mass.
#79
Premier Member
iTrader: (25)
Install was just short of 2 shop hours, it cost me 130 to have it done. The mechanic said it was quite a bitch to get the stock pulley off, but afte that it was a breeze. I've seen on other cars double digit hp gains with pulleys, so they do offer some hp on different set-ups, not just revs. I'm willing to bet I see an increase, it's not just a feel thing, the car is noticably faster compared to my friends cars, i can't believe its just from the weight reduction. I weighed my stock pulley and it came in at 8.8 lbs, UR pulley was 1.5.
#81
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Join Date: Jul 2007
Location: Colorado Springs, CO
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WOW !!! I CANT BELIEVE YOUR ACTUALLY SAYING YOUR BUTT DYNO IS TELLING YOU THAT THE CAR IS FATSER !! WOULD THAT BE A MISLEADING FACT LIKE YOU BASHED ME ON WHEN I POSTED MY REVIEW OF THE JWT ??? WHERE IS YOUR DYNO ??? DOES EVERYTHING YOU PUT ON YOUR CAR MAKE IT FASTER ?? IF YOU GO TO MY 350Z.COM THERE IS A GUY WHO BOUGHT THE UR CRANK PULLEY FOR HIS HR AND DYNOED IT AND GUESS WHAT ??? NO GAINS !! SO CAN YOU STOP MISLEADING THIS COMMUNITY IN REGARDS TO YOUR BUTT DYNO !!!!!!!!
#84
Premier Member
iTrader: (25)
When it comes to a lighter pulley it does not increase horsepower or allow you to rev quicker . All your doing is making your car lighter . Seven pounds lighter is not going to make you faster . Now if you combine that with other mods like a lighter exhaust and test pipes and remove your spare tire and anything else that you can think of than yeah you will be faster . The best bang for the buck mod for a na car is switching out your gears. That will allow you to rev faster get through the gears quicker and have way better launches !
#85
Premier Member
iTrader: (25)
When it comes to a lighter pulley it does not increase horsepower or allow you to rev quicker . All your doing is making your car lighter . Seven pounds lighter is not going to make you faster . Now if you combine that with other mods like a lighter exhaust and test pipes and remove your spare tire and anything else that you can think of than yeah you will be faster . The best bang for the buck mod for a na car is switching out your gears. That will allow you to rev faster get through the gears quicker and have way better launches !
#87
Premier Member
iTrader: (25)
When it comes to a lighter pulley it does not increase horsepower or allow you to rev quicker . All your doing is making your car lighter . Seven pounds lighter is not going to make you faster . Now if you combine that with other mods like a lighter exhaust and test pipes and remove your spare tire and anything else that you can think of than yeah you will be faster . The best bang for the buck mod for a na car is switching out your gears. That will allow you to rev faster get through the gears quicker and have way better launches !
#88
Premier Member
iTrader: (17)
Neverbonestock, if you read my posts you would see I am dynoing, the appointment is for friday, I'm not just reviewing from my butt dyno, it was my initial review before actual numbers. As far revving faster with the pulley, it does, you're an idiot if you think it doesn't. The amount of time it takes my 5AT to go through the rpm's and hit it's shift point has been cut down. I'm hitting second and third gear quicker with the pulley. As far as HP gains, here is how it works. From UR:
100% of the power gains from the stock diameter pulleys comes only from weight reduction versus the factory crank pulley. The reduced weight allows for more power transfer to the drive wheels. Weight reduction is how we are able to increase Horsepower. Each pound of weight removed from the crankshaft is worth approximately 2.7HP and the gains jump even more dramatically with forced induction, nitrous and variable valve timing.
Our engines have VVEL, I don't believe 350z's have VVEL, but i might be wrong. I know VVEL played a big role in all the drama with aftermarket intakes. as far as I'm concerned, we'll see whats up on friday, and I'm sure i'll be correct
100% of the power gains from the stock diameter pulleys comes only from weight reduction versus the factory crank pulley. The reduced weight allows for more power transfer to the drive wheels. Weight reduction is how we are able to increase Horsepower. Each pound of weight removed from the crankshaft is worth approximately 2.7HP and the gains jump even more dramatically with forced induction, nitrous and variable valve timing.
Our engines have VVEL, I don't believe 350z's have VVEL, but i might be wrong. I know VVEL played a big role in all the drama with aftermarket intakes. as far as I'm concerned, we'll see whats up on friday, and I'm sure i'll be correct
#89
Hp
An old school thought. What is horse power? A unit (550 ft. lb.s per sec.) used to calculate the effort required to move a object. So the heavier the object the more effort (HP) required to move it. The lighter we make our car the quicker it will reach terminal velocity.
#90
Super Moderator w/ Boost
iTrader: (3)
When it comes to a lighter pulley it does not increase horsepower or allow you to rev quicker . All your doing is making your car lighter . Seven pounds lighter is not going to make you faster . Now if you combine that with other mods like a lighter exhaust and test pipes and remove your spare tire and anything else that you can think of than yeah you will be faster . The best bang for the buck mod for a na car is switching out your gears. That will allow you to rev faster get through the gears quicker and have way better launches !
If thats the case... Ill start charging 250 bucks for a bite of my chit. One nibble off a Turd and you will throw up... therefor losing wieght... hence your car has lost a few lbs... I can even sponsor a few guys who are willing to lose a lil weight for speed Yea thats gross... but its true... a less disgusting way would be laxatives... but dont tell anyone ... it will hurt my sales