What underdrive pulley to buy?

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Dec 10, 2008 | 10:03 PM

#21

BackinBlack02SS

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They reduce drag by slowing down the accessories thereby freeing up lost HP. You can purchase overdrive pulleys for some applications. You may want to go this route if there are issues from something turning too slow.

Dec 10, 2008 | 10:18 PM

#22

1MeanGreenZ28

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From: Scott City, MO

Wow, already a lot of responses. Sweet, so an SLP or ASP would be fine?

Dec 11, 2008 | 06:28 AM

#23

BlackScreaminMachine

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From: Wallingford CT

I have the SLP, love the high retaining wall, running on a stock belt tensioner w/ 44k on it with no issues. It is SFI cert as well.

Dec 11, 2008 | 08:10 AM

#24

dre2013

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From: Akron OH

i think im gonna run the summit one..mainly b/c summit racing is only 15min away from me

Dec 11, 2008 | 09:07 AM

#25

on2

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I say go for the Summit/eBay/BBK pulley. Because it's the cheapest, best looking, has high retaining walls, clearcoated, and is SFI approved.

Dec 11, 2008 | 05:55 PM

#26

01ssreda4

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From: Turnin' Wrenches Infractions: 005

Quote:

Originally Posted by on2

I say go for the Summit/eBay/BBK pulley. Because it's the cheapest, best looking, has high retaining walls, clearcoated, and is SFI approved.

and the heaviest too i believe, not that it makes that much difference.

Dec 11, 2008 | 11:27 PM

#27

on2

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From what I've read the ASP pulleys weigh 10 lbs. 1.5 lbs difference is not going to be felt. It is the 25% underdrive that increases the power and response.

Dec 12, 2008 | 12:37 PM

#28

Fast Toys Performance Parts

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Quote:

Originally Posted by on2

From what I've read the ASP pulleys weigh 10 lbs. 1.5 lbs difference is not going to be felt. It is the 25% underdrive that increases the power and response.

Weight is the enemy of performance. Reciprocating weight is an even worse enemy

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Dec 12, 2008 | 04:59 PM

#29

FireSilverLullaby

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From: Chesapeake,va and Charlotte,NC

Quote:

Originally Posted by toothdoc

That is a good deal, but I don't know if you want to get the alternator pulley for an A4 though.

I was thinking of getting an under drive pulley, why shouldnt i get the alternator overdrive one as well? my lights dim a little when my music is up real loud, so i dont want any less power from my alt.

Dec 14, 2008 | 09:51 PM

#30

1MeanGreenZ28

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From: Scott City, MO

Well, it looks like this thread is really growing. Thanks for all the advice and please keep the responses coming.

Dec 14, 2008 | 11:50 PM

#31

00Corvette

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From: Redding, CA

I was gonna ask the same question, cause I have an A4 and was considering an UD pulley but also have an 1100 watt stereo...

Why not use the bigger alt pulley?

Thanks so much!
Donnie

Dec 15, 2008 | 12:25 AM

#32

ZMONSTER!

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From: Fresno, California

Ill be going with the summit when I get one.

Dec 15, 2008 | 01:25 AM

#33

BackinBlack02SS

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Quote:

Originally Posted by 00Corvette

I was gonna ask the same question, cause I have an A4 and was considering an UD pulley but also have an 1100 watt stereo...

Why not use the bigger alt pulley?

Thanks so much!
Donnie

I would try it without the overdrive alt pulley first. If you need more voltage, go ahead and install it.

Dec 15, 2008 | 03:52 PM

#34

FireSilverLullaby

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From: Chesapeake,va and Charlotte,NC

yeah i think my stock alt is at its limit right now so im probably gonna go ahead and get the overdrive alt pulley too.

Dec 15, 2008 | 04:05 PM

#35

Fast Toys Performance Parts

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ASP Pulleys

If you order an ASP pulley from us, you can specify an under driven or over driven alternator pulley.

Generally, M6 cars can get away with the under drive crank and alt pulleys as long as they are not running some killer stereo.

Auto's generally just go with crank only unless they are stuck in traffic a lot at idle and have a lot of current draw (stereo etc).

Thanks!

Dec 15, 2008 | 05:53 PM

#36

BackinBlack02SS

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It's very simple. Stock A4 idle is 550 rpm. Stock M6 idle is 800 rpm. Using simple math you SHOULD be able to slow down the accessories 31.25% on an M6 with no problems.