Underdrive pulley help?!?!?!
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Underdrive pulley help?!?!?!
How much hp can i expect from an underdrive pulley? i have a cat back exhaust and a jwt pop charger, and also how hard are they to install?? help is greatly appriciated.
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The after-market underdrive crank pulley (KJR or UR) will lighten your rotational mass for the pulley. So that put less stress on the alternator and the engine. Which then improves your throttle response and free up a little HP and TQ. The lighten pulley will help your engine rev up a little faster than the stock pulley.
Average HP increases from 5-8. TQ increases anywhere from 3-6 lbs.
Average HP increases from 5-8. TQ increases anywhere from 3-6 lbs.
Last edited by leatherface_ca; 04-23-2006 at 10:59 PM.
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It also underdrives the AC, so you loose less HP on the AC. Guess you culd also just shut it off ?
Don't get one if you plan on going Supercharged...
Danny
Don't get one if you plan on going Supercharged...
Danny
Originally Posted by leatherface_ca
The after-market underdrive crank pulley (KJR or UR) will lighten your rotational mass for the pulley. So that put less stress on the alternator and the engine. Which then improves your throttle response and free up a little HP and TQ. The lighten pulley will help your engine rev up a little faster than the stock pulley.
Average HP increases from 5-8. TQ increases anywhere from 3-6 lbs.
Average HP increases from 5-8. TQ increases anywhere from 3-6 lbs.
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There is a reason the factory puts a balancer on the front of the motor and it's not a good idea to take it off. If you want to loose some rotational weight and get the car to rev quicker get a lighter flywheel.
You can read a little about them here http://www.dinancars.com/whitepapersFile.asp?ID=5
Chris
You can read a little about them here http://www.dinancars.com/whitepapersFile.asp?ID=5
Chris
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Originally Posted by HyperSprite
There is a reason the factory puts a balancer on the front of the motor and it's not a good idea to take it off. If you want to loose some rotational weight and get the car to rev quicker get a lighter flywheel.
You can read a little about them here http://www.dinancars.com/whitepapersFile.asp?ID=5
Chris
You can read a little about them here http://www.dinancars.com/whitepapersFile.asp?ID=5
Chris
EDIT: I just looked at the pic again and actually that's a pic of a PULLEY + a HARMONIC BALANCER. Our cars don't have an harmonic balancer, just the pulley.
Another objection I have to the article is how it speaks about a perfectly balanced harmonic balancer, yet leaves out to discuss the effect the belt has on the pulley. Belts can be less or more tight (and stretch over time), which would really affect the pulleys behaviour (it's "weight").
Danny
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if going supercharged dont get the UR get the KJR as stated above
ive never installed one but i hear its fairly simple (i did read the instructions for it and it seems pretty easy)
ive never installed one but i hear its fairly simple (i did read the instructions for it and it seems pretty easy)
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Originally Posted by dscheers
This might be true for a BMW, but since the shown pulley doesn't look anywhere near the ones on the 350Z, I doubt it's true for our cars.
EDIT: I just looked at the pic again and actually that's a pic of a PULLEY + a HARMONIC BALANCER. Our cars don't have an harmonic balancer, just the pulley.
Another objection I have to the article is how it speaks about a perfectly balanced harmonic balancer, yet leaves out to discuss the effect the belt has on the pulley. Belts can be less or more tight (and stretch over time), which would really affect the pulleys behaviour (it's "weight").
Danny
EDIT: I just looked at the pic again and actually that's a pic of a PULLEY + a HARMONIC BALANCER. Our cars don't have an harmonic balancer, just the pulley.
Another objection I have to the article is how it speaks about a perfectly balanced harmonic balancer, yet leaves out to discuss the effect the belt has on the pulley. Belts can be less or more tight (and stretch over time), which would really affect the pulleys behaviour (it's "weight").
Danny
Chris
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Originally Posted by rkd350z
Does every pully has different size?
Since a Supercharger relies on stock size crank pulley to turn it the correct rpm and make the correct amount of boost, they also make lightweight pullies in stock size.
Danny
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