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2.75" crush bent vs. 3" mandrel

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Old 09-26-2014, 10:37 AM
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Default 2.75" crush bent vs. 3" mandrel

Is the 1/4", smoother bends worth the huge price difference? How much difference is it going to make anyway on a n/a 5.7?

Don't mean to sound like an a** but please only answer if you actually know the answer...like you have experienced the difference first hand or
know someone that has and not just answer based on what you heard. Don't want to make a decision based on myths.

Thanks!
Old 09-26-2014, 12:14 PM
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I would say it really just depends on your HP goals. If your just looking to slap on an exhaust and not looking for big numbers or crisp clean sound then go with whatever fits your budget.
Old 09-26-2014, 12:19 PM
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Don't know never ran crushed bend stuff.
Old 09-26-2014, 12:28 PM
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Oh yeah will the 1/4" make a difference when it comes to sound on a twin x pipe?
Old 09-26-2014, 01:35 PM
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I'd personally make the decision on something like that based on price. For instance, a friend of mine made under the axle duals for his LT1 car with standard pipe and bender, but only because it was essentially free as his brother owned the repair shop.

Considering stainless 3" true duals can be had for $300-$400, it'd need to be virtually free for me to run 2.75" crushed pipe.
Old 09-26-2014, 02:19 PM
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Are we talking about a stock type catback or duals with a x pipe?
Old 09-26-2014, 03:05 PM
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Originally Posted by Fry_
Are we talking about a stock type catback or duals with a x pipe?
Duals with x pipe
Old 09-26-2014, 11:35 PM
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Fact, crush bends restrict flow. The tighter the bend the more flow restriction you have. So to minimize any loss in flow you need to go with as little bend angle as possible, and with as few as many bends as possible. Furthermore you'll want to also go with a larger diameter pipe than you would IF you were using mandrel bends to offset the reduced pipe size in the bends.

You really can't compare pipe size when using crush bends, since a 2.75" diameter pipe won't flow any better than its tightest/largest crush bend angle. So a 2.75" pipe might not flow any better than a 2" or 2-1/2" pipe depending on the bends put in it.

Last edited by 99Bluz28; 09-27-2014 at 12:42 AM.
Old 09-27-2014, 03:26 AM
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Originally Posted by 99Bluz28
Fact, crush bends restrict flow. The tighter the bend the more flow restriction you have. So to minimize any loss in flow you need to go with as little bend angle as possible, and with as few as many bends as possible. Furthermore you'll want to also go with a larger diameter pipe than you would IF you were using mandrel bends to offset the reduced pipe size in the bends.

You really can't compare pipe size when using crush bends, since a 2.75" diameter pipe won't flow any better than its tightest/largest crush bend angle. So a 2.75" pipe might not flow any better than a 2" or 2-1/2" pipe depending on the bends put in it.
Makes sense. Guess ill have to go mandrel then. Thanks for your input buddy!
Old 09-27-2014, 08:19 AM
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Are you asking about manderal bent pipes for true duals over the axle?
If so you can buy those pieces already made by dynomax.
Old 09-27-2014, 11:26 AM
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I'd run mandrel bends if there is anyway you can afford it!
Old 09-29-2014, 06:17 AM
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Originally Posted by bad_408_vert
Are you asking about manderal bent pipes for true duals over the axle?
If so you can buy those pieces already made by dynomax.
You mean the elbows? And then weld them together?
Old 09-29-2014, 07:49 AM
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Not quite, look up Dynomax 53303 and Dynomax 54299

These can be used behind the mufflers to bring exhaust over the axle, and out the back.



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