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Underdrive Pulleys

Discussion in 'Chevy Truck Accessories' started by KyleZ71, Jul 19, 2010.

  1. KyleZ71

    KyleZ71 Rockstar 4 Years 500 Posts ROTM Winner

    I've read that aftermarket underdrive pulleys can lead to an increase in fuel mileage and and increase in horsepower as well. I've been told that these are not that good of an investment, so has any one here installed them or what are some thoughts on them.
  2. wis bang

    wis bang Rockstar 100 Posts

    I've heard good and bad, depending on your driving style and how your truck is equipped. If you do alot of high RPM driving the smaller water pump pulley saves gas. If you have a massive amp & other additional power draws the smaller alternator pulley causes problems.
  3. Metaluzc

    Metaluzc Rockstar 4 Years 100 Posts

    I've read that they can help release up to 12HP but don't know anyone personally, who has installed them. Seems like a quick, cheap add-on for that type of HP gain, if they do work. Best way to determine if they work is to buy the pulley and have your truck dynoed before and after installation. The old "butt-in-seat Dyno" can just be the placebo effect. Listen to wis bang and use the least amount of additional power draws.
  4. silveradotrailblazer

    silveradotrailblazer Epic Member 5+ Years ROTM Winner 5000 Posts

    I had a set on a my IROC Camero years ago and I hated them. The slowed the power steering down and made it hard to steer. Also my alternater didn't charge like it should. I ended up removing them. I think there fine if all you do is drag race.
  5. KyleZ71

    KyleZ71 Rockstar 4 Years 500 Posts ROTM Winner

    Thanks just wanted to know some peoples thoughts on them.
  6. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    I've used them before, while I did get a horsepower increase at the rear wheels the side effects like poor power steering response, terrible recovery rate on my battery charge, weak A/C, and prematurely toasted 2 alternators I didnt think the HP increase was worth the hassle. As was posted if all you do is race the vehicle this is a great performance enhancing mod, for a daily driver it might be worth a second thought.
  7. KyleZ71

    KyleZ71 Rockstar 4 Years 500 Posts ROTM Winner

    Did not know that at all. Thanks guys, I'd rather keep my silverado without the ten extra horses and without the extra hassle.
  8. reggiecab2000

    reggiecab2000 Rockstar 4 Years 500 Posts

    i was just reading up on this, and this thread definitely just helped me make up my mind, no underdrive pulleys for me!
  9. KyleZ71

    KyleZ71 Rockstar 4 Years 500 Posts ROTM Winner

    yeah i did the same thing. a lot of hype, but you dont hear of the negatives

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