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  #8485  
Old 08-19-2014, 03:57 AM
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Re: What did you do to your WK today?

So, just outta curiosity, how does/would changing two pulleys fix the PITA dead spot @30 mph?

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  #8486  
Old 08-19-2014, 04:05 AM
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Originally Posted by Truck.Norris View Post
So, just outta curiosity, how does/would changing two pulleys fix the PITA dead spot @30 mph?
From what i know, this kit will make it easier to spin the engine up by reducing drag. There is quiet abit of drag on our accessories while the engine is not in the powerband. How my engine pulls up top, the underdive kit will get results close to that off idle even tho torque management is still there.

Basically less drag off idle means a quicker rev up. Faster rev up means you get to the powerband faster
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  #8487  
Old 08-19-2014, 04:22 AM
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Re: What did you do to your WK today?

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Originally Posted by Strongjeff View Post
Gotcha. But i dont think it would have worked

It might, I've saved a few using it. It just depends how bad the corrosion is from the differing metal cap and how long it's been on there. The problem is probably also compounded if he lives in an area that uses salt on the roads, not sure where he's at.
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  #8488  
Old 08-19-2014, 04:36 AM
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Re: What did you do to your WK today?

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Originally Posted by Truck.Norris View Post
So, just outta curiosity, how does/would changing two pulleys fix the PITA dead spot @30 mph?

It works on the simple theory of ratios. The smaller pulley on the crank allows it to spin up quicker, lessening the drag on the belt created by your belt driven accessories (A/C comp, P/S pump, alt, water pump, etc...) The possible down side is you're not spinning said accessories at the rpms they were designed to run at (~25% less) so they may not create the proper pressures, P/S may lack a bit, water pressure may be insufficient, charging may lag, A/C may not be as effective. We're talking fairly negligible reductions in speed though so it may be a non issue, those are just some of the 'possible' trade offs. The power gains will be small, but the quickness in accel is the goal and should be noticeable.
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  #8489  
Old 08-19-2014, 04:48 AM
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Re: What did you do to your WK today?

Quote:
Originally Posted by Rkirk View Post
It works on the simple theory of ratios. The smaller pulley on the crank allows it to spin up quicker, lessening the drag on the belt created by your belt driven accessories (A/C comp, P/S pump, alt, water pump, etc...) The possible down side is you're not spinning said accessories at the rpms they were designed to run at (~25% less) so they may not create the proper pressures, P/S may lack a bit, water pressure may be insufficient, charging may lag, A/C may not be as effective. We're talking fairly negligible reductions in speed though so it may be a non issue, those are just some of the 'possible' trade offs. The power gains will be small, but the quickness in accel is the goal and should be noticeable.
Makes sense. In simple physics, it's (hypothetically) a 1:1 ratio (each pulley is the same size). If the crank pulley is reduced (2:1), the crank spins 2x for every 1 time the accessory pulley turns.

So Josh could be right; A/C & PS quality would suffer?
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  #8490  
Old 08-19-2014, 04:57 AM
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Re: What did you do to your WK today?

Quote:
Originally Posted by Truck.Norris View Post
Makes sense. In simple physics, it's (hypothetically) a 1:1 ratio (each pulley is the same size). If the crank pulley is reduced (2:1), the crank spins 2x for every 1 time the accessory pulley turns.



So Josh could be right; A/C & PS quality would suffer?

You got it, but the pulley is a 25% under drive in actual so not as drastic as a 2:1 from a 1:1, I know that was just an example. In theory the pumps 'could' be less effective, but I can't say for sure, they may operate above what they need to in the oem configuration so the UD won't even drop them below nominal operating speed, I can't say for certain. I would assume the company that makes them would take that into consideration when they decide how small to go so maybe this is a non issue and we're spit ballin ideas for nothing... If one of y'all do it to the 3.7, post up the results so we know a lil more. Jeff, sounds like you're already planning the install when you get back stateside??
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  #8491  
Old 08-19-2014, 05:41 AM
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Originally Posted by Rkirk View Post

You got it, but the pulley is a 25% under drive in actual so not as drastic as a 2:1 from a 1:1, I know that was just an example. In theory the pumps 'could' be less effective, but I can't say for sure, they may operate above what they need to in the oem configuration so the UD won't even drop them below nominal operating speed, I can't say for certain. I would assume the company that makes them would take that into consideration when they decide how small to go so maybe this is a non issue and we're spit ballin ideas for nothing... If one of y'all do it to the 3.7, post up the results so we know a lil more. Jeff, sounds like you're already planning the install when you get back stateside??
Im planning it yes
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  #8492  
Old 08-19-2014, 06:07 AM
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Re: What did you do to your WK today?

I wanna try it, too. Good thing I only need the A/C 6 months out of the year!
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  #8493  
Old 08-19-2014, 06:23 AM
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Re: What did you do to your WK today?

There's some talk about it here (and a harmonic balancer [is it necessary?]):

3.7L & 4.7L ATI Harmonic Damper & UNDERDRIVE PULLEY
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  #8494  
Old 08-19-2014, 06:35 AM
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Quote:
Originally Posted by Truck.Norris View Post
There's some talk about it here (and a harmonic balancer [is it necessary?]):

3.7L & 4.7L ATI Harmonic Damper & UNDERDRIVE PULLEY
Well its not necessary but as any performance part. ....you want it
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  #8495  
Old 08-19-2014, 06:37 AM
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Re: What did you do to your WK today?

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Originally Posted by Strongjeff View Post
Well its not necessary but as any performance part. ....you want it
10-4! If I *need*, I want it.
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  #8496  
Old 08-19-2014, 11:02 AM
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Re: What did you do to your WK today?

I was responding to a post from a person who could not loosen a line nut, and was using the wrong type of wrench and also rounding off the nut using a cresent wrench... I'm not sure why it showed up at this tread location. But it also just might work on the wheel valve stem cap also, now that you mentioned it
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