Ls3 exhaust Question
Thread Starter
Burning Brakes
Joined: Jun 2009
Posts: 1,065
Likes: 7
From: Madison, MS
Ls3 exhaust Question
i did a search and found a lot of useful information, but not really on what I am looking for..
I have a 13 grand sport 6 speed car. It's still under warranty until 2019. Trying to do little things that won't void my warranty. I saw that ls7 exhaust is a good upgrade. Couple questions.
1. Is the older ls7 exhaust an hpipe also, and if so should I look for hpipe or xpipe?
2. I love the way the npp exhaust sounds, so would I be to just modify the
2.5 inch rear section, to the 3 inch mid pipes? And if so would that be smart or not as it may create a pinch point in exhaust flow?
3. Any need for different O2 sensors??
If I can pickup 10-15 hp by spending a couple hundred dollars, and retaining warranty that would be a win for me. Any help would be great appreciated. Thanks.
I have a 13 grand sport 6 speed car. It's still under warranty until 2019. Trying to do little things that won't void my warranty. I saw that ls7 exhaust is a good upgrade. Couple questions.
1. Is the older ls7 exhaust an hpipe also, and if so should I look for hpipe or xpipe?
2. I love the way the npp exhaust sounds, so would I be to just modify the
2.5 inch rear section, to the 3 inch mid pipes? And if so would that be smart or not as it may create a pinch point in exhaust flow?
3. Any need for different O2 sensors??
If I can pickup 10-15 hp by spending a couple hundred dollars, and retaining warranty that would be a win for me. Any help would be great appreciated. Thanks.
Team Owner
Joined: Sep 2005
Posts: 20,352
Likes: 568
From: Ventura County, Calif
1. I'm not positive but I think the LS7 used an H-pipe until 2011. The 2008 LS3's started with X-pipes. X-pipes are more efficient but there isn't a huge difference. Most think the X-pipe systems sound better.
2. The LS7 3" exhaust reduces to 2 1/2" at the muffler inlet so it is a simple cut and weld job to attach your NPP mufflers to the LS7 pipes. Just make sure to measure and cut carefully. Many have done it over the years.
3. As long as you are using the LS7 manifolds your O2 sensors will fit fine.
2. The LS7 3" exhaust reduces to 2 1/2" at the muffler inlet so it is a simple cut and weld job to attach your NPP mufflers to the LS7 pipes. Just make sure to measure and cut carefully. Many have done it over the years.
3. As long as you are using the LS7 manifolds your O2 sensors will fit fine.
