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underdrive pulley

Discussion in 'General Tech and Maintenance' started by mozzandherb, Jul 3, 2005.

  1. mozzandherb

    mozzandherb Senior Member

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    I'm thinking of getting a Bomz underdrive pulley for an H22 v-tec. I was wondering because I'm a newbie and don't know too much, do I have to buy more than just this 1 pulley or can I get just get the underdrive pulley by itself? Also does it make a difference by switching this 1 pulley?
     
  2. mozzandherb

    mozzandherb Senior Member

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    Hello!! Anyone here can help me...
     
  3. K2e2vin

    K2e2vin Senior Member

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    gains arent really that big...do you have a pic of this underdrive pulley?
     
  4. wanderinman

    wanderinman Senior Member

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    Not really worth the time or effort unless its a fullout race motor.
     
  5. mozzandherb

    mozzandherb Senior Member

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    It's Ebay # 7983873341
     
  6. xj0hnx

    xj0hnx I wanna be sedated VIP

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    Sometimes it takes more than a whole hour for someone that has an answer for you to get on line.
     
  7. mozzandherb

    mozzandherb Senior Member

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    True
     
  8. phyregod

    phyregod !!YTINASNI

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    The underdrive alone should be fine. You do get a couple of extra horses, but where the real gain is, I believe, is that the underdrive weighs like 2 pounds, and the stock one weighs something like 11 pounds. That lowers your rotational mass So your motor revs quicker, making it feel like it has more power. Its a good mod in my opinion.
     
  9. dohcvtec_accord

    dohcvtec_accord WRX Sellout

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    Bomz makes crap. If you're looking for an underdrive pulley (ESPECIALLY a crank pulley), spend the extra cash and get a quality one. It's not the best idea to replace these anyway, but if you're stuck on it, get something good.
     
  10. xj0hnx

    xj0hnx I wanna be sedated VIP

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    I am thinking about get the Unorthodox pulleys, as I just added my AC back in, and it could stand a little lightening in the work load. Unorthodox have been good as far as I know, and they are real helpful poeple.
     
  11. HatchSpeeD

    HatchSpeeD ...Hi...

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    I was interested in getting a crank pulley a few years ago but there was this big discussion with people saying not to get one because something about it messing up the crank. I heard people say that when you get a lightweight crank pulley that it messes up the balance and something about it not dampening right & then you have to get your bottomend balanced and its not worth it. Any of this true because my stocker has a big chip on the pulley and would like to upgrade as well.
     
  12. xj0hnx

    xj0hnx I wanna be sedated VIP

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    Look at your crank pulley, if it has a rubber ring around it anywhere don't relpace it, but I can almost garantee you it doesn't.
     
  13. spydy43

    spydy43 Senior Member

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    In my experienced opinion most of the aftermarket crank pulleys suck due to the lack of a harmonic balancer. I had a UR crank pulley and within a year of having it on my car I spun a bearing sure I noticed a little bit of a gain but it was not worth it. Save your money and stay away from most of the bolt-on crap out there. If you arelooking for noticeable power gains either save up to build up the motor for NA or go with some sort of forced induction.
     
  14. MikeBergy

    MikeBergy Blah blah blah....

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  15. abdelsol

    abdelsol Member

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    Look at a Fuidampr. It had way less rotaional mass than a stock damper and will reduce vibration caused by the the power stock of your engine.
     
  16. xj0hnx

    xj0hnx I wanna be sedated VIP

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    A Honda crank pulley is NOT a harmonic balancer. SOME of them have a rubber insert that is for isolating noise, not balancing the engine. Your spun bearing more than likely came from ragging on your motor, age, or just bad luck. Hundreds, probably thousands of people use aftermarket pullies and there hasn't been a cataclysmic backlash of bearing failures, now has there?
     
  17. MikeBergy

    MikeBergy Blah blah blah....

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    I disagree. The rubber is there to eliminate the lower order torsional vibs of the crankshaft. Yes, most bearing failures come as a result of other problems in the engine, usually inadequacy of lube issues, as was my case, with a little bad luck thrown in. As for all the people running race pulleys, the people who benefit most from them are actual sponsored racers, who are going to rebuild the engine after racing it anyway. It's a waste of good money IMO, unless you get it for like $20. As for those saying it will allow your motor to rev faster, that is true, but the over all effects of the crank pulley on the MOI compared to that of the flywheel are small; MOI is influenced by a rotating object's radius^4. Replace the flywheel if you are looking for an easier revving motor.
     
  18. abdelsol

    abdelsol Member

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    Almost, Cars do not have balancer but the Harmonic Damper is real and does provide a vital function. That Rubber is not for noise but to absorb and reduce the vibrations from combustion. Whe the engine fires it induces a tortional load on the crankshaft. This load is very harmful to your engine, causing harmonic vibrations to set up as is oscillates back and forth.

    It is a very common error to refer to the harmonic damper as a harmonic balancer.
     
  19. dohcvtec_accord

    dohcvtec_accord WRX Sellout

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    FYI, Vishnu (one of the top tuners of WRXs, EVOs and Miatas) includes an underdrive crank pulley in the Stage 0 (and up) power packages. To my knowledge, they have yet to have one complaint resulting from problems associated with crank pulleys.

    Maybe it's because my engine makes quite a bit of power, but I definitely noticed a better throttle response after replacing my crank pulley.
     
  20. MikeBergy

    MikeBergy Blah blah blah....

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    totally different type of engine, lol.
     
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