Exhaust Question

Discussion on fuel delivery & intake/exhaust tech & mods.
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BossAwesome
Posts: 7
Joined: Thu Nov 10, 2016 4:09 am
Location: Michigan

Exhaust Question

Post by BossAwesome »

My 2012 Caprice has Solo axle backs on it, but I want to make it louder and get more performance out of it. I know the Solo axlebacks have 2.5 inch piping, and I know stock exhaust is 2.5 inch piping until it hits the mid muffler, where it necks down to 2.25. I plan on removing the precats, mid muffler, and resonators, and installing an X pipe. So my question is, should I just cut those out and replace with piping that is correct size(cheap route), or replace the entire mid section of the exhaust with 2.5 inch all the way back to the axlebacks? How much performance gain is there in going from 2.25 to 2.5 inch piping, and is that gain worth the extra cost? Any feedback is welcome!
2012 Caprice PPV 6.0
xcidmigs
Posts: 783
Joined: Fri Feb 13, 2015 8:12 pm
Location: SE PA

Re: Exhaust Question

Post by xcidmigs »

stock exhaust did not use any 2.5" pipe anywhere that I can find. My 2011 has 2.25" tubing from the manifolds back except those parts you noted as smaller. The real restriction lies inside the connector areas between the manifolds and down pipe and then in the mid muffler and inside the flex connector at the axle back. All those connections have less than 2" ID pieces. If you are serious you would need to replace all that stock stuff with 2.5 tubing. Check these pics...

http://newcaprice.com/forum/viewtopic.php?f=16&t=121" onclick="window.open(this.href);return false;
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Raunchtastic
Posts: 113
Joined: Fri Sep 25, 2015 10:53 pm

Re: Exhaust Question

Post by Raunchtastic »

It sounds like you are trying to do exactly what I did. I ran a 2.5" X pipe (the cheap stamped one, not a real merge pipe) into 2.5" tubing back to the factory connectors. No cats, no mid muffler, etc. It makes for a great sound, but if you have factory manifolds, it is getting choked at the flex point before anything else. It will probably drone much worse, as well. Long tubes eliminated that choke point and the drone for me. My phone doesn't want to upload photos, but I'll see if I can link to my Facebook and upload them there. I don't think there was too much performance gained, I just needed all new piping due to frozen bolts and failed flex pipes in from of the primary cats. Here is a YouTube sound clip of it now with factory G8 GT muffler, then below that is no muffler.

https://youtu.be/V_d7Cb4ZYLk" onclick="window.open(this.href);return false;

https://youtu.be/Z6pSJ4SWFbU" onclick="window.open(this.href);return false;
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2012 Chevrolet Caprice "The Daily"
1992 Chevrolet Camaro RS 25th anniversary "The Wannabe Racecar"
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Raunchtastic
Posts: 113
Joined: Fri Sep 25, 2015 10:53 pm

Re: Exhaust Question

Post by Raunchtastic »

This should show the photo of the exhaust.

https://m.facebook.com/photo.php?fbid=1 ... 7&__tn__=E" onclick="window.open(this.href);return false;
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2012 Chevrolet Caprice "The Daily"
1992 Chevrolet Camaro RS 25th anniversary "The Wannabe Racecar"
brenard
Posts: 27
Joined: Sun May 03, 2015 10:22 pm

Re: Exhaust Question

Post by brenard »

I doubt that you will see noticeable hp gain by just using bigger pipe.
CrashTestDummy
Posts: 2300
Joined: Sat Feb 07, 2015 2:31 pm
Location: Pearland, Texas

Re: Exhaust Question

Post by CrashTestDummy »

Raunchtastic wrote:This should show the photo of the exhaust.

https://m.facebook.com/photo.php?fbid=1 ... 7&__tn__=E" onclick="window.open(this.href);return false;
Soul-sucking registration required to see.
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2012 Caprice 9C1
1992 B4C 1LE Camaro
2018 Tahoe PPV (her car)
1995 DGGM Impala SS
1985 Firebird - 310 LS1 C Prepared autocross car.
1980 Bluebird Wanderlodge
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