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  1. #1

    Default Underdrive Pulleys

    I've heard recently that underdrive pulleys supposedly significantly decrease the strain on your motor, and help make more horsepower and torque. Has anyone heard anything like this, could it actually be as good as it sounds? Any help would be appreciated.

  2. #2
    Sr. Engineer
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    They can free up some power but the gains aren't huge.
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  3. #3
    Master Mechanic Silverado Junkie's Avatar
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    JennaBear is right, the gains arent huge but they're there. But idd go for 'em because a littlebit here and there adds up after a while and then becomes a big overall improvement in your performance.
    1995 Silverado,Z71, 3-inch lift,2-inch leveling kit, SkyJacker Suspension, short ram-air intake, throttle body spacer, MSD ignition coil, straight pipes

  4. #4

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    well i did all kinds of work to my 06 6.0L and i ran a dyno number at 625hp and 680 ft lbs. then all i did was put under drive pullys on and numbers came in a 636hp and 688 ft lbs. so ya they do help a bit

  5. #5
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    Was that on a load bearing dyno?

  6. #6
    Jr. Engineer Jacqson's Avatar
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    Quote Originally Posted by Jarrett View Post
    I've heard recently that underdrive pulleys supposedly significantly decrease the strain on your motor, and help make more horsepower and torque. Has anyone heard anything like this, could it actually be as good as it sounds? Any help would be appreciated.
    Underdrive pulleys will also make your alternator and any other belt driven items like the fan turn slower so at idle your probably going to get less amps from the alternator and less airflow through the rad. Mind you if you don't do a lot of idling or city driving in weather that puts a strain on your alt or rad then it's not really a big deal.
    2011 Chevy Silverado 3500HD, Dmax/Allison, Taupe Gray Metallic, Line-x over the Rail & Rockers, S&B Intake, Banks Monster Exhaust, Rigid Dually D2's, Cognito Leveling Kit, Cognito Steering Braces plus much more.

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