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Does anyone make a dual 2-1/2 to single 4" merge pipe?

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Old Dec 22, 2010 | 10:41 AM
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Does anyone make a dual 2-1/2 to single 4" merge pipe?

I am going to be running a single 4" exhaust and I am trying to tie two 2-1/2 inch pipes to it without too much of a hassle. I have been looking for a merge/y pipe that will work but I cant seem to find anything. Has anyone seen one out there or am I going to have to make my own?
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Old Dec 22, 2010 | 12:47 PM
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Re: Does anyone make a dual 2-1/2 to single 4" merge pipe?

Flowmaster might make the merge connector. The part number would be something like 250400.
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Old Dec 22, 2010 | 01:05 PM
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Re: Does anyone make a dual 2-1/2 to single 4" merge pipe?

No luck, they have 3" to 4" and 2-1/2" to 3-1/2". I may just have to go wuth the 2-1/2 to 3-1/2 and just step it up to 4 with an adapter. Kind of sucks.
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Old Dec 22, 2010 | 01:12 PM
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From: Cypress, California
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Transmission: 4L60E
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Re: Does anyone make a dual 2-1/2 to single 4" merge pipe?

Actually the 3.50" pipe is almost identical in area to two 2.5" pipes. So you will not be losing much. Remember the further away from the heat source(engine) the cooler and denser the exhaust gas becomes. So you do not need as big a diameter to flow the same amount of exhaust gas.
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Old Dec 23, 2010 | 09:21 AM
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Car: 92 25th anv z28
Engine: 346 TC78 Turbo
Transmission: 4L80E
Axle/Gears: 3.25 9"Nodular, Strange axles
Re: Does anyone make a dual 2-1/2 to single 4" merge pipe?

I ended up making one. Put the 4" pipe in a vice and ovaled it installed the 2 2.5" pipes in the end. Creased it with a chisal and welded it up.
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Old Dec 23, 2010 | 02:01 PM
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Re: Does anyone make a dual 2-1/2 to single 4" merge pipe?

Well I just made one...easy enough. I used a vice, ball peen hammer and a welder...done.
Attached Thumbnails Does anyone make a dual 2-1/2 to single 4" merge pipe?-img00007-20101223-1429.jpg  
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Old Dec 23, 2010 | 06:04 PM
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Transmission: 4L60E
Axle/Gears: 3.70 Nine Bolt
Re: Does anyone make a dual 2-1/2 to single 4" merge pipe?

"Well I just made one...easy enough"

Hehehehe. I love it. Looks like you did a nice job of it. Hot rodding at its finest.
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Old Dec 23, 2010 | 11:47 PM
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Re: Does anyone make a dual 2-1/2 to single 4" merge pipe?

Thanks!
Now I just need to get the rest of the bends and muffler to get this 4" exhaust done. I just couldn't take the resonance of the dual 2-1/2's exiting under the car...that and they scraped on just about everything.
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Old Jan 1, 2011 | 10:01 PM
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From: League City, TX
Car: 90 Formula -- tot resto in progress
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Transmission: 700R4 w/ 2500 stall, by Owen @ ARD
Axle/Gears: 3.23 posi disc
Re: Does anyone make a dual 2-1/2 to single 4" merge pipe?

Nice looking piece of work.

But I'm having trouble connecting the dots.
What kind of 4" muffler, mounted where, with
what kind of tailpipes. I assume no cat(s)?

Throw up some pics of progress, and final product.
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Old Jan 2, 2011 | 02:04 PM
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Re: Does anyone make a dual 2-1/2 to single 4" merge pipe?

Originally Posted by l_dis_travlr
Nice looking piece of work.

But I'm having trouble connecting the dots.
What kind of 4" muffler, mounted where, with
what kind of tailpipes. I assume no cat(s)?

Throw up some pics of progress, and final product.
I am planning on using a 4" dynomax round ultra flo muffler. I will be putting it in the stock location (under the gas tank) I have a sumped tank but it looks like it will still fit with plenty of room. I will bee running one 4" tail pipe exiting on the drivers side.
I will try to get some pics up. It is a custom setup but pretty much like the mufflex system.
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Old Jan 10, 2011 | 03:00 PM
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From: sussex county, NJ
Car: 84 Z28 / 11 genesis coupe
Engine: 355/210 heads/275deh/Proform 750 DP
Transmission: 700r4/B&M 2400
Axle/Gears: 02, allu.axle, 3.42, posi
Re: Does anyone make a dual 2-1/2 to single 4" merge pipe?

it's not that hard going from dual 2.5 to 4, i had to merge dual 2.5 to 3", rigt under the passanger side header
Attached Thumbnails Does anyone make a dual 2-1/2 to single 4" merge pipe?-imag0017.jpg  
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