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Discussion Starter #1
Where can I get a set of underdrive pulleys & what kind of money are we talking?
I've looked around & haven't been able to find a set.
 

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07 TrailblazerSS
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I've talked to them They don't sell them only the single pulley for the crankshaft.
Thanks for your inquiry - honestly the crank one is the only one we usually do anyway. The TBSS's already have a not so great charging system, so I don't suggest underdriving the alternator any more or the light flickering might get worse. The crank pulley on its own though is usually good for 5-7hp.
 

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Discussion Starter #7
Thanks for your inquiry - honestly the crank one is the only one we usually do anyway. The TBSS's already have a not so great charging system, so I don't suggest underdriving the alternator any more or the light flickering might get worse. The crank pulley on its own though is usually good for 5-7hp.
Kelly, Thank you for your help yesterday & Thank all that chimed in on this subject.
Now I understand why I can't find a set.
I'll be ordering the pulley in the next week or so.
 

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Kelly, Thank you for your help yesterday & Thank all that chimed in on this subject.
Now I understand why I can't find a set.
I'll be ordering the pulley in the next week or so.
Did you ever get the UD pulley on? if you did how was it? not entirely sure $240 is worth the 5-8 HP.


Thanks for your inquiry - honestly the crank one is the only one we usually do anyway. The TBSS's already have a not so great charging system, so I don't suggest underdriving the alternator any more or the light flickering might get worse. The crank pulley on its own though is usually good for 5-7hp.
I am looking for the most cost effective "bolt on parts" for the power and money. something I can knock out after work or on the weekend

thanks guys
 

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2007 AWD 3SS
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Thanks for your inquiry - honestly the crank one is the only one we usually do anyway. The TBSS's already have a not so great charging system, so I don't suggest underdriving the alternator any more or the light flickering might get worse. The crank pulley on its own though is usually good for 5-7hp.
Not wanting to derail this thread, but, since you replied and since it might inform the original poster a little: Do you know if a smaller alternator pulley that has the clutch is available?

Before you ask why I ask, let me explain:

1. The alternator power draw depends on electric current required to regulate voltage, nothing else. It only loads the engine down as much as the power draw requires, no matter how fast its actually spinning. Spinning the alternator faster will actually help meet electric demands at low engine speeds and won't have any effect on engine drag except during hard acceleration, then its a matter of spinning the rotor mass up, but, its not like I am looking for super low rotating mass drag race style shit, just want my stereo to not cause as much flickering when the engine is idling.

2. Any alternator pulley I would be interested in absolutely has to have the clutch like the factory pulley does because I am not interested in throwing belts when I let off after hitting passing gear that ends up happening with aftermarket alternator/pulleys that do not have the clutch.
 

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Thanks for your inquiry - honestly the crank one is the only one we usually do anyway. The TBSS's already have a not so great charging system, so I don't suggest underdriving the alternator any more or the light flickering might get worse. The crank pulley on its own though is usually good for 5-7hp.
Reducing the alternator pulley size overdrives the alternater to counteract the crank pulley size reduction. Your logic is exactly backwords. On a weak charging system, you should always recommend the alt overdrive (smaller) pulley.

Not trying to be a dick, just clearing up some misinformation for future modders looking into ud pulleys.
 

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BBA I had the alternator pulley but never installed it. I doubt there is one with the clutch available as there was hardly any room left between the splined bore and ID of hub to put a clutch.

So I am betting no.

Not trying to be a dick, just clearing up some misinformation for future modders looking into ud pulleys.
This is true. The Alt pulley is actually overdrive.
 

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Reducing the alternator pulley size overdrives the alternater to counteract the crank pulley size reduction. Your logic is exactly backwords. On a weak charging system, you should always recommend the alt overdrive (smaller) pulley.

Not trying to be a dick, just clearing up some misinformation for future modders looking into ud pulleys.
Ok, nevermind my previous response, though you quoted me wrong but you quoted Kelly..
 

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BBA I had the alternator pulley but never installed it. I doubt there is one with the clutch available as there was hardly any room left between the splined bore and ID of hub to put a clutch.

So I am betting no.



This is true. The Alt pulley is actually overdrive.
Thanks, that's what I was wondering.
 

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So another question: Does anyone make a larger size waterpump pulley, and a larger size AC pulley?

The combination of those two would achieve the same thing as a smaller crank pulley, but with the benefit of not underdriving the alternator and not having to give up the alternator clutch.
 

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I have an underdrive and my lights surge some at idle. If it had a smooth idle it probably wouldn't be a problem at all. When they dim it's not like they are barely working. You just notice it when you are close to a car or something but it's not bad at all.
 
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