A6 LS3 Exhaust Questions
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Joined: Mar 2011
Posts: 79
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From: Columbia Missouri
A6 LS3 Exhaust Questions
I am finally at the point where I want to modify my 2008 LS3 Vette. I currently have an SLP Blackwing Intake, and I am looking to go the exhaust route next. Probably a Catless system, as I love the sound and smell and performance.
My previous car was a Subaru WRX that I had modified exhaust and a few other things. In order to do so, I had to get a reflash on the ECU in order to keep it from getting boost spike, clear codes from removing cat, etc.
My questions (I did search, but it didnt reveal exactly what I was looking for):
-What should I start with? I want to keep the stock axleback or possiblly a z06 system because I love the NPP.
-Will I have to retune it just for a catless x-pipe? I know I wont get 100% of power without it, so that is a non issue. I will tune it eventually, but I want to run around for a bit before I get to it, without consequences, of course.
-What kind of performance gain should I expect from just an x-pipe? I know sound will increase and will be an awesome gain for me, even a stock Vette is not slow by any means...
My previous car was a Subaru WRX that I had modified exhaust and a few other things. In order to do so, I had to get a reflash on the ECU in order to keep it from getting boost spike, clear codes from removing cat, etc.
My questions (I did search, but it didnt reveal exactly what I was looking for):
-What should I start with? I want to keep the stock axleback or possiblly a z06 system because I love the NPP.
-Will I have to retune it just for a catless x-pipe? I know I wont get 100% of power without it, so that is a non issue. I will tune it eventually, but I want to run around for a bit before I get to it, without consequences, of course.
-What kind of performance gain should I expect from just an x-pipe? I know sound will increase and will be an awesome gain for me, even a stock Vette is not slow by any means...
Racer
Joined: Jun 2009
Posts: 326
Likes: 1
From: Las Vegas Nevada
My 2 cents
You will need to retune the car if you remove the cats as it will set catalyst inefficiencey codes without them. Cats generate oxygen which is measured by the rear o2 sensors. A tuner would need to set the PCM to ignore those sensors, then check the A/F ratio and fuel trim to look for other possible changes. I think it's unlikely you will see any gains from removing the cats and installing an X pipe unless you're installing headers. The Manifolds are more restrictive than the cats. You would however notice less heat from the tunnel as the cats increase the exhaust temps by at least 30% if they work. I think an H pipe is actually more noisey than an X, esspecially on decel. I believe an X gives you better exhaust equalization. That's why Chevy put them in 09 and up C6s.
I say leave the cats, install an X pipe, mod the baffles inside the mufflers, install a switch inline with the exh module circuit for control, then go out and play.
I say leave the cats, install an X pipe, mod the baffles inside the mufflers, install a switch inline with the exh module circuit for control, then go out and play.
Last edited by Yawlak80-86; Dec 18, 2011 at 10:44 PM.
