Exhaust Performance
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Joined: Feb 2016
Posts: 74
Likes: 3
Exhaust Performance
Im looking to do a full aftermarket exhaust on my 2008 LS3.
Question is what exhaust size will get the most power out of my car. If im going N/A full bolt ons.
Another thing is if I miss match 3" headers with 2 1/2 " Xpipe. Is that any good ?
Question is what exhaust size will get the most power out of my car. If im going N/A full bolt ons.
Another thing is if I miss match 3" headers with 2 1/2 " Xpipe. Is that any good ?
Melting Slicks
Joined: Jun 2006
Posts: 2,491
Likes: 261
From: Miami Florida
With the ls3 if you want as much you can get for the money expend get 1 1/8 primerys 3 inch collectors and full 3 inch exhaust anywhere a turn down to 2 1/2 is found is a restriction BUT is ok to start somewhere, headers along is a huge improvement.
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,106
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
LG Streets w/ 1.75 primaries to a 3" collector into gutted cats and exiting into a 2.5 X-pipe and then through Z06 mufflers.
But then again I could be wrong and still be the quickest on the bolt-on list.
But then again I could be wrong and still be the quickest on the bolt-on list.
Le Mans Master
Joined: Oct 2012
Posts: 8,434
Likes: 411
From: Texas
Kooks 1 7/8" headers seem to have about the highest overall HP on an LS3. If you have an LS2, due to the different head design you definitely need to stick with 1 3/4" primary headers. The cats don't hurt you at all.
Corsa told me that their 2.5 muffler system makes considerably more midrange power and the same top end than their straight 3" until you get really high hp, over 700 or something. To top it off the 2.5" is about $500 cheaper than the 3" version of the same (if that's the brand you choose).
Good luck!
Corsa told me that their 2.5 muffler system makes considerably more midrange power and the same top end than their straight 3" until you get really high hp, over 700 or something. To top it off the 2.5" is about $500 cheaper than the 3" version of the same (if that's the brand you choose).
Good luck!
Le Mans Master
Joined: Apr 2011
Posts: 7,820
Likes: 411
From: Montreal
St. Jude Donor '13
You would gain nothing from going to 3 inch. If anything you would lose low end torque with a bigger exhaust.
No clue how people figure 2.5 is a restriction for a bolt on car.
No clue how people figure 2.5 is a restriction for a bolt on car.
Racer
Joined: Jul 2015
Posts: 323
Likes: 15
From: Clayton NC
I have Kooks 1-7/8" headers with their 3" catless mid-pipe and the factory NPP mufflers.
I'm making 539 rwhp / 510 rwtq on my LS3 all motor on stock heads. Hoping to get that up a little more with some Trickflow 255 heads this summer.
I love the way it sounds, and the power band / torque curve is amazing.
I'm making 539 rwhp / 510 rwtq on my LS3 all motor on stock heads. Hoping to get that up a little more with some Trickflow 255 heads this summer.
I love the way it sounds, and the power band / torque curve is amazing.
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,106
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
The bigger is better crowd are not racers. They don't understand thermal dynamics, let alone volumetric efficiency. Then again, there are many racers who simply spend cubic dollars to go fast without understanding why it works.
The old saying "If a whole lot is good then too much will be just right" only referred to the percentage of the nitro load.
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Burning Brakes
Joined: Jul 2014
Posts: 757
Likes: 47
From: Tracy CA
Bolt on ls3 here. 1 7/8" lg super pros. 3 inch catless xpipe. Down to 2.5 inch at the axle back. Went faster with open xpipe but still necks down to 2.5 inch at the end of the Xpipe. With the full exhaust did 10.7. Mufflers off and a couple extra pounds out of the car trapped 3mph faster
Safety Car
Joined: Feb 2007
Posts: 4,684
Likes: 107
From: Opelika Alabama