Exhaust system advice
Thread Starter
Racer
Joined: Jun 2017
Posts: 269
Likes: 42
From: TX
Exhaust system advice
I have a 2015 z51 with NPP. I have come up to the conclusion that the sound i like involves getting LT headers and an offroad xpipe, and while still keeping the NPP mufflers. However I am still a bit unclear on some details that I hope some of you can clear up
1) I am unclear about the cats and their location. I understand that our cars have primary and secondary cats? So with the set-up I am looking into, does that involve getting rid of one set of cats, or both? I have seen some xpipes that come with cats attached and alot that don't. Which will give me no CEL codes (car will be tuned after install)?
2) When mentioning "off-road" xpipe is that a specific model of a brand or does it mean xpipe with no cats on it from any manufacturer?
3) I see there are a few different measurements of header and xpipe diameters. What implications does this have? My understanding is that 2" LT and 3" xpipe is ok for my car. Would these sizes be ok if I plan to add a supercharger later on?
1) I am unclear about the cats and their location. I understand that our cars have primary and secondary cats? So with the set-up I am looking into, does that involve getting rid of one set of cats, or both? I have seen some xpipes that come with cats attached and alot that don't. Which will give me no CEL codes (car will be tuned after install)?
2) When mentioning "off-road" xpipe is that a specific model of a brand or does it mean xpipe with no cats on it from any manufacturer?
3) I see there are a few different measurements of header and xpipe diameters. What implications does this have? My understanding is that 2" LT and 3" xpipe is ok for my car. Would these sizes be ok if I plan to add a supercharger later on?
Instructor
Joined: Aug 2017
Posts: 184
Likes: 35
From: New York City
I have a 2015 z51 with NPP. I have come up to the conclusion that the sound i like involves getting LT headers and an offroad xpipe, and while still keeping the NPP mufflers. However I am still a bit unclear on some details that I hope some of you can clear up
1) I am unclear about the cats and their location. I understand that our cars have primary and secondary cats? So with the set-up I am looking into, does that involve getting rid of one set of cats, or both? I have seen some xpipes that come with cats attached and alot that don't. Which will give me no CEL codes (car will be tuned after install)?
2) When mentioning "off-road" xpipe is that a specific model of a brand or does it mean xpipe with no cats on it from any manufacturer?
3) I see there are a few different measurements of header and xpipe diameters. What implications does this have? My understanding is that 2" LT and 3" xpipe is ok for my car. Would these sizes be ok if I plan to add a supercharger later on?
1) I am unclear about the cats and their location. I understand that our cars have primary and secondary cats? So with the set-up I am looking into, does that involve getting rid of one set of cats, or both? I have seen some xpipes that come with cats attached and alot that don't. Which will give me no CEL codes (car will be tuned after install)?
2) When mentioning "off-road" xpipe is that a specific model of a brand or does it mean xpipe with no cats on it from any manufacturer?
3) I see there are a few different measurements of header and xpipe diameters. What implications does this have? My understanding is that 2" LT and 3" xpipe is ok for my car. Would these sizes be ok if I plan to add a supercharger later on?
2 cats are located in the exhaust manifold/downpipes which you'd replace with LT or high flow cat mid headers. The other 2 cats are located in the mid x pipe. 'Offroad' x pipes will delete the secondary cats and not throw any codes but borla discontinued theirs so you can still go with the other popular corsa option. Other street legal x pipes require cutting your cats off and clamping them onto the x.
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Joined: Oct 2004
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From: Manassas Park VA
St. Jude Donor '07-'08,-'13-'14, '16-'17
I have a 2015 z51 with NPP. I have come up to the conclusion that the sound i like involves getting LT headers and an offroad xpipe, and while still keeping the NPP mufflers. However I am still a bit unclear on some details that I hope some of you can clear up
1) I am unclear about the cats and their location. I understand that our cars have primary and secondary cats? So with the set-up I am looking into, does that involve getting rid of one set of cats, or both? I have seen some xpipes that come with cats attached and alot that don't. Which will give me no CEL codes (car will be tuned after install)?
2) When mentioning "off-road" xpipe is that a specific model of a brand or does it mean xpipe with no cats on it from any manufacturer?
3) I see there are a few different measurements of header and xpipe diameters. What implications does this have? My understanding is that 2" LT and 3" xpipe is ok for my car. Would these sizes be ok if I plan to add a supercharger later on?
1) I am unclear about the cats and their location. I understand that our cars have primary and secondary cats? So with the set-up I am looking into, does that involve getting rid of one set of cats, or both? I have seen some xpipes that come with cats attached and alot that don't. Which will give me no CEL codes (car will be tuned after install)?
2) When mentioning "off-road" xpipe is that a specific model of a brand or does it mean xpipe with no cats on it from any manufacturer?
3) I see there are a few different measurements of header and xpipe diameters. What implications does this have? My understanding is that 2" LT and 3" xpipe is ok for my car. Would these sizes be ok if I plan to add a supercharger later on?
2" would be appropriate for a FI car
Four cats (2 sets) Primary and Seconday
Any LTH set will eliminate the secondary cats
You can choose cats or no cats for the primaries
Off road is no cats (all cats) and not a brand
Let me know if you have anymore question
Glad to help
Regards
Chip
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Team Owner
Joined: Jan 2007
Posts: 29,059
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From: cookeville tennessee
Ttt
Man do the 1 7/8 LT headers with no cats 3 inch mid pipe. Really man your car doing this to it WILL not be that much louder at all with NO drone at all. As me how I know this you will like the sound over the stock & this set up REALLY sound good at WOT... Robert
