3" vs 2.5" exhaust ANSWER!

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77 K20

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I just happened to come across this:

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In this video they take a L98 Chevy 350 and then run dual exhaust with 3" on the dyno. Then replace it with 2.5" dual exhaust. Both of these systems are using Magnaflow mufflers.

Then they swapped out the Magnaflows with some cheap Thrush mufflers. Then ran the dyno again.

I've seen discussions/arguments about this for years. So I thought this was very interesting.

I'm glad I'm running 2.5" duals with Magnaflows.
 

Honky Kong jr

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I watch that show every month good info. And I'm glad I have 3" And 10 series.lol
 

77 K20

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Watching more of their stuff... H pipe vs X pipe vs no cross pipe

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crazy4offroad

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I think I watched 4 hours straight of engine masters when I first discovered their show. A lot of solid info on there for squeezing power out of your powerplant.
 

bucket

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I love these two episodes. Two old wife's tales proved wrong.
 

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I found the cooling fan episode very informative
 

Jrgunn5150

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But my velocity!!!!!!!!!!!!!

The two downsides to 3" in the real world, are that it's more expensive by a fair bit, and harder to package. Then again my DD has 3" duals from the factory, so I guess GM didn't care.
 

Honky Kong jr

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But my velocity!!!!!!!!!!!!!

The two downsides to 3" in the real world, are that it's more expensive by a fair bit, and harder to package. Then again my DD has 3" duals from the factory, so I guess GM didn't care.
20 bucks a 10' stick aluminized 3" pipe here locally.
 

MikeB

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Good to see testing of real world engines. Wonder how my Dynomax Super Turbos would do? Their inside diameter doesn't "neck down" like the Thrush turbos and David Vizard likes them.

On a related note, I once had a pair of 2.25" Walker Sound FX mufflers that necked down to 1.75" inside.:eek: Probably just a little power loss there!
 

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Yup. But I do my own just pie cut and weld it
Your lucky, I ended buying a stainless kit for the Nova, but then again it was cheaper than a local shop that was going to use plain steel and crush bends..
 

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Your lucky, I ended buying a stainless kit for the Nova, but then again it was cheaper than a local shop that was going to use plain steel and crush bends..
I always do my own this is the first in a while I used actual exhaust pipe tho lol I usually use EMT that measures out to 2.75"ID.
 

Jrgunn5150

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Your lucky, I ended buying a stainless kit for the Nova, but then again it was cheaper than a local shop that was going to use plain steel and crush bends..


Yeah, I either buy the bends, or scrounge them from the scrap bin of the local Muffler Man for mine.

I need to redo my square exhaust, it's just heads to Flowmasters to dumps, it's annoying lol.
 

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