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How much more efficient is a 12 bolt than a 9 inch?

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Old 11-28-2007, 01:15 PM
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Exclamation How much more efficient is a 12 bolt than a 9 inch?

still trying to decide on the 9inch or 12 bolt still how much more efficient is the 12 bolt as far as power? i know the 9inch is heavier but how much heavier is it?
Old 11-28-2007, 02:20 PM
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i pulled the 12 bolt out of the camaro on sunday to replace with a 10 bolt and i forgot how much weight difference there was between the two. I liked my 12 bolt but i can't answer your question.
Old 11-28-2007, 02:27 PM
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Agreed.

Everyone here will have a favorite rear, either way its better then a 10 bolt.
Old 11-28-2007, 04:05 PM
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i really dont think you'll notice a difference performance wise between the 9" and the 12 bolt rear. only real difference is how simple each is to work on. that being said, i prefer the 12 bolt.
Old 11-28-2007, 07:29 PM
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I think the difference is a 2-3% in power loss i.e. 9" with 400 hp would be like 412 hp with a 12 bolt.
Old 11-28-2007, 09:36 PM
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if your gonna race alot or drive hard 9"
if its a street car 12 bolt should be fine.
Old 11-28-2007, 11:05 PM
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9" for m6 and 12 bolt for A4. If it was me I would go with a 9" for your applicationn
Old 11-28-2007, 11:39 PM
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im trying to decide on aluminum case or iron...
Old 11-28-2007, 11:41 PM
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Originally Posted by donkey mule
9" for m6 and 12 bolt for A4.

That about says it all.
Old 11-29-2007, 06:01 AM
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Personally, I'd go 9 inch and be done with it. I seriously doubt your butt will feel the difference in horsepower, mine never could. Bob




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