2.5 vs 2.25 diameter exhaust

Discussion on fuel delivery & intake/exhaust tech & mods.
CrashTestDummy
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Re: 2.5 vs 2.25 diameter exhaust

Post by CrashTestDummy »

AND if you're running stock cats, THE restriction is just before the front cat. It's like 1-11/16", or so there, so a 5" cat back is going to do nothing for you.
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Numbah1
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Re: 2.5 vs 2.25 diameter exhaust

Post by Numbah1 »

Not stock cats, i have the JBA catted connection pipes. They meet the 3 inch primary off the header and at some point come down to 2.5 inch. I still have the pup cats on near the diff though
s/c'd cav
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Re: 2.5 vs 2.25 diameter exhaust

Post by s/c'd cav »

there is no pup cat near the diff , the pup cats were right behind the flanges for the mid section next to the trans

you might be talking about the resonators
Numbah1
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Re: 2.5 vs 2.25 diameter exhaust

Post by Numbah1 »

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What ever these are, are they restrictive??
s/c'd cav
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Re: 2.5 vs 2.25 diameter exhaust

Post by s/c'd cav »

they look like resonators , restrictive minimal
CapriceX2
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Re: 2.5 vs 2.25 diameter exhaust

Post by CapriceX2 »

Numbah1 wrote: Wed Oct 07, 2020 7:31 pm What ever these are, are they restrictive??
I don't know how restrictive the resonators are. I'm working on my exhaust now, so I'll try to cut the pipe off and check them out. But... the pipe going into them is under 2". Mine measured 1.988.
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CapriceX2
2011 Caprice 9C3 - TSP 220R W/ DOD delete, 10.8:1 Compression, Custom Stainless Exhaust
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Numbah1
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Re: 2.5 vs 2.25 diameter exhaust

Post by Numbah1 »

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Yea!! The up bend after the x pipe that clears that super thin cross brace measures 1.98 OD on mine too. Im on the hunt for camaro exhaust now. 2.25 my ass
Numbah1
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Re: 2.5 vs 2.25 diameter exhaust

Post by Numbah1 »

I put a 2.5 x pipe on after the JBA connection pipes and took an L99 Vert Camaro system into the muffler shop, i used square stock from work and hose clamps to wedge the butterfly valve in the bends around the diff on with same 2.5 cutouts and stock mufflers,,,

Didnt go any faster, sounds better though! Idk maybe i shouldn't have used catted connection pipes lol but yea, the 2.0 vs 2.5 didnt matter on ETs
JUNKYARD_JACK
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Re: 2.5 vs 2.25 diameter exhaust

Post by JUNKYARD_JACK »

Lots of info in this thread but does anyone have any known issues with using 3in exhaust tubes and clearance?

I thought about picking up something like this, I don't think the price can be beat. Less than a $20 difference between the 2.5in and 3in exhaust.

https://www.speedwaymotors.com/DIY-Univ ... 76010.html

That way I can make it just like I want it and have full 3in duals with H pipe back to the factory muffler and still have the option to go with a more aggressive aftermarket muffler if I want.
Pursuit
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Re: 2.5 vs 2.25 diameter exhaust

Post by Pursuit »

A post from way back, with some measurements... for reference

https://www.newcaprice.com/forum/viewto ... 99+exhaust

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