Smaller S/C Pulley

Discussion in '2005 - 2009 Specific Tech' started by p1tst0p, Oct 9, 2007.

  1. p1tst0p New Member

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    Hey,

    Does anyone know if there is an install guide for smaller supercharger pulley and idler installation? i bought one that has no instructions!

    I'm thinking its as easy as, loosening the nuts, pushing the belt tensioner and slipping the belt off, taking the pulleys off completely and replacing them, then push the tensioner again and hook the belt back on.

    Do the nuts for the idler/ supercharger pulley need to be tightened with a Torque Wrench?

    Many thanks.

    Will
  2. Gearbanger 101 SuperMod

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    First off....what kind of supercharger is it?
  3. p1tst0p New Member

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    Sorry, good point!

    its a Roush supercharger.
  4. Gearbanger 101 SuperMod

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    The Roush uses an Eaton M90, which utilizes a keyway to hold the pulley in place and not a press fit pulley like the larger M112. So yes, swapping the pulley is as easy as taking the tension off the belt, sliding it off the pulley, removing the nut, sliding the old one off and sliding the new one on.

    You'll have to be conservative with pulley diameter though. Get too small and you'll require a complete retune. You might also have to worry about belt slip, since you're now increasing the slack in the serpentine system. Your tensioner may be able to make up the difference, but only if you remain conservative with your pulley selection. Another reason not to go overboard on the pulley size, is that you're now decreasing belt wrap around said pulley. With less surface area for belt contact, slipping the serpentine belt could be a problem.

    ...and when you do get it changed over, torque the supercharger nut to about 50 ft.-lbs of torque.
  5. p1tst0p New Member

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    Many thanks for your prompt response!

    As for slack, i have been given an idler pulley in addition to the smaller pulley to take up the slack. im asuming this would replace the idler below the S/C pulley? and again this can be replaced easily while the belt is off ?

    Thanks again!
  6. Gearbanger 101 SuperMod

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    I'm not sure how the Roush 3V kit has it's belt routing, so I'm going based on the 2V design here. If in fact it is just a matter of swapping out the pulley on the front cover, then yeah....I think it's just one 10mm bolt holding it on. Just as long as the larger pulley doesn't interfere with the front cover in any way. That seems to be a problem for us 2V guys. And yes, once the belt is removed, it should be easy to access.
  7. p1tst0p New Member

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    Anyone know of a way to losen the roush supercharger pulley nut without an impact gun!

    It just turns.. so i cant get it off.

    Thanks!
  8. 7r3s3oqk37ums0f New Member

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    Loosen the nut while the belts still on.
  9. Gearbanger 101 SuperMod

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    Yup....that would be my advice. If that doesn't work, try putting a short wrench or ratchet on the nut and give the other end a whack with a rubber mallet. Most of the time you just need that suddent "jolt" to crack the nut loose. It should then turn off without issue.

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