C7 x-pipe options
Thread Starter
Cruising
Joined: Jun 2022
Posts: 10
Likes: 1
C7 x-pipe options
Hello C7 owners. I need your input on trying to get my 2018 C7 Stingray a little louder. Currently everything is stock and I'm thinking about possible removing the cats near the mufflers. The only problem is that I noticed that Corsa and Borla no longer sell the catless x-pipe. I have seen on ebay that they sell something similar, but it's 2 pieces and it comes with clamps. I was either thinking of going to a muffler shop and having them cut off the cats and weld on an attachment to the current pipe or I can buy the ebay product (2 pieces) and take it the the muffler shop and have them install it and also weld on the 2 pieces. Not sure how much of a sound difference it would make removing the cats. Would it be a little louder? Also, anyone that did this have problems passing the emissions test?
Melting Slicks
Joined: May 2007
Posts: 3,248
Likes: 767
From: Lindenhurst, IL
I'm using this Corsa Double Helix knock-off on my Z06. It's well-made, and it fits perfectly. FYI - all C7's use the same x-pipe.
https://cornerstoneperformancesoluti...42447001944318
I can't tell you how much sound difference it made because I installed it at the same time as Corsa Xtreme mufflers.
I initially had only purchased the x-pipe. But after "exhaustive" research, I convinced myself that it wouldn't be loud enough for my taste. So, I opted to install new mufflers as well. I'm glad I did.
If you like an even "slightly loud" and/or deep exhaust note, I don't believe that you will be satisfied with just the x-pipe. If I could only choose 1, I would go with the mufflers instead of the x-pipe.
And since you asked, removing the secondary cats from the x-pipe will not affect the emissions test.
https://cornerstoneperformancesoluti...42447001944318
I can't tell you how much sound difference it made because I installed it at the same time as Corsa Xtreme mufflers.
I initially had only purchased the x-pipe. But after "exhaustive" research, I convinced myself that it wouldn't be loud enough for my taste. So, I opted to install new mufflers as well. I'm glad I did.
If you like an even "slightly loud" and/or deep exhaust note, I don't believe that you will be satisfied with just the x-pipe. If I could only choose 1, I would go with the mufflers instead of the x-pipe.
And since you asked, removing the secondary cats from the x-pipe will not affect the emissions test.
Burning Brakes
Joined: Aug 2006
Posts: 1,219
Likes: 820
From: Bay Area, CA
Assuming you car has the factory NPP dual mode exhaust on it, adding an X-pipe would make it ~25% louder under normal acceleration and ~75% louder WOT. That's the setup I have and I think it perfect. It will have the same tone as stock while being louder when you want it to.
The purpose of the x2 small secondary cats on the stock mid-pipe is to reduce emissions on startup, once the car is warmed in they don't really do anything to further clean the air so they will pass the sniffer test once warmed up. The Borla and Corsa X-Pipe (discontinued) both look just like factory once installed plus the aluminum brace covers most of it so I'm fairly certain the smog technician won't be able to tell it's aftermarket.
It's unfortunate Borla and Corsa and possibly AWE discountied the X-Pipes due to the EPA cracking down on manufacturers but I would be wary to buy Manzo's product. If possible and your situations allows, try to source responsibly.
The purpose of the x2 small secondary cats on the stock mid-pipe is to reduce emissions on startup, once the car is warmed in they don't really do anything to further clean the air so they will pass the sniffer test once warmed up. The Borla and Corsa X-Pipe (discontinued) both look just like factory once installed plus the aluminum brace covers most of it so I'm fairly certain the smog technician won't be able to tell it's aftermarket.
It's unfortunate Borla and Corsa and possibly AWE discountied the X-Pipes due to the EPA cracking down on manufacturers but I would be wary to buy Manzo's product. If possible and your situations allows, try to source responsibly.
Drifting
Joined: Jun 2013
Posts: 1,428
Likes: 478
From: Maryland, USA
just get one Ken mentioned or the EOS, it will resolve your situation for cheap.
not worth the effort modding your stock xpipe, id keep it intact and buy replacement aftermarket. that way you can return to stock.
no emissions issue, especially since they are not monitored and there is a tunnel plate that covers stuff.
https://extremeonlinestore.com/colle...7e59f781&_ss=c
looks like eos is out of stock again, so that might be your issue currently.
you can try to find used as well.
good luck.
not worth the effort modding your stock xpipe, id keep it intact and buy replacement aftermarket. that way you can return to stock.
no emissions issue, especially since they are not monitored and there is a tunnel plate that covers stuff.
https://extremeonlinestore.com/colle...7e59f781&_ss=c
looks like eos is out of stock again, so that might be your issue currently.
you can try to find used as well.
good luck.
Racer
Joined: Sep 2021
Posts: 267
Likes: 102
From: Prosper, TX
Then I added the Corsa headers to the X-pipe and kept the stock NPP exhaust. That made a HUGE difference.
After a few months I decided the drone was too bad when the NPP exhaust valves opened up, so I went all in and added the Corsa Extreme Variable exhaust. WOW! Now it’s loud enough to scare kids and adults out of their shoes.
It’s PERFECT now!
Thread Starter
Cruising
Joined: Jun 2022
Posts: 10
Likes: 1
I'm using this Corsa Double Helix knock-off on my Z06. It's well-made, and it fits perfectly. FYI - all C7's use the same x-pipe.
https://cornerstoneperformancesoluti...42447001944318
I can't tell you how much sound difference it made because I installed it at the same time as Corsa Xtreme mufflers.
I initially had only purchased the x-pipe. But after "exhaustive" research, I convinced myself that it wouldn't be loud enough for my taste. So, I opted to install new mufflers as well. I'm glad I did.
If you like an even "slightly loud" and/or deep exhaust note, I don't believe that you will be satisfied with just the x-pipe. If I could only choose 1, I would go with the mufflers instead of the x-pipe.
And since you asked, removing the secondary cats from the x-pipe will not affect the emissions test.
https://cornerstoneperformancesoluti...42447001944318
I can't tell you how much sound difference it made because I installed it at the same time as Corsa Xtreme mufflers.
I initially had only purchased the x-pipe. But after "exhaustive" research, I convinced myself that it wouldn't be loud enough for my taste. So, I opted to install new mufflers as well. I'm glad I did.
If you like an even "slightly loud" and/or deep exhaust note, I don't believe that you will be satisfied with just the x-pipe. If I could only choose 1, I would go with the mufflers instead of the x-pipe.
And since you asked, removing the secondary cats from the x-pipe will not affect the emissions test.
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Thread Starter
Cruising
Joined: Jun 2022
Posts: 10
Likes: 1
Thread Starter
Cruising
Joined: Jun 2022
Posts: 10
Likes: 1
This is not true at all. I added the Corsa X-Pipe and I honestly couldn’t tell a difference at all. I “wanted” to hear a difference, but honestly couldn’t tell at all.
Then I added the Corsa headers to the X-pipe and kept the stock NPP exhaust. That made a HUGE difference.
After a few months I decided the drone was too bad when the NPP exhaust valves opened up, so I went all in and added the Corsa Extreme Variable exhaust. WOW! Now it’s loud enough to scare kids and adults out of their shoes.
It’s PERFECT now!
Then I added the Corsa headers to the X-pipe and kept the stock NPP exhaust. That made a HUGE difference.
After a few months I decided the drone was too bad when the NPP exhaust valves opened up, so I went all in and added the Corsa Extreme Variable exhaust. WOW! Now it’s loud enough to scare kids and adults out of their shoes.
It’s PERFECT now!
Race Director
Joined: Mar 2001
Posts: 19,964
Likes: 6,768
From: Bonneville Salt Flats
I cannot speak for louder since that's the last thing I want... to yell at gendarmes to look at me. But, if you find an X-pipe you like and cannot locate one for sale, If you can get a decent picture and take it and your car to a good muffler shop they should be able to fab a dupe and install it for you. All the best. 
Always Shiftin'
Joined: Jun 2000
Posts: 4,028
Likes: 939
From: Central Florida
2025 C7 of the Year Finalist - Modified
2024 C7 of the Year Finalist - Modified
2023 C7 of the Year Finalist - Unmodified
2019 C5 of Year Finalist (stock)
After a lot of research, I decided on the Extreme Online Store's (EOS) X-pipe. Very happy with the quality and fitment of their x-pipe assembly. Installation is very reasonable as long as you have the tools and medium mechanical skills. Don't let the two piece assembly scare you away. If anything it allows for a little more flexibility during installation. AND you can't beat the $260 price!!
The link below is to a thread that discusses the installation process. I made the link take you to where @MA ZO6 starts discussing his installation. As you read down the page I added some additional information that might prove helpful if you go the EOS route.
EOS X-Pipe Thread
The link below is to a thread that discusses the installation process. I made the link take you to where @MA ZO6 starts discussing his installation. As you read down the page I added some additional information that might prove helpful if you go the EOS route.
EOS X-Pipe Thread
Racer
Joined: Mar 2017
Posts: 297
Likes: 67
From: Coweta, OK
https://speed-engineering.com/collec...t4-lt5-engines
I went with this one. with stock NPP it's noticeably better sounding. i went this route as it's one piece unlock the EOS that has a Middle joint that gets clamped. Install was super easy on a lift even after driving the car to my buddies house and doing it while everything was still hot/warm from the drive. 10/10 would buy the same set up again.
I went with this one. with stock NPP it's noticeably better sounding. i went this route as it's one piece unlock the EOS that has a Middle joint that gets clamped. Install was super easy on a lift even after driving the car to my buddies house and doing it while everything was still hot/warm from the drive. 10/10 would buy the same set up again.
Racer
Joined: Jun 2016
Posts: 280
Likes: 216
From: Massachusetts
EOS has the one piece X-pipe without the cats. I did that first and thought it sounded slightly throatier, not really louder.
Did AWE touring set up last year at Carlisle and that completed the sound.
Did AWE touring set up last year at Carlisle and that completed the sound.
Always Shiftin'
Joined: Jun 2000
Posts: 4,028
Likes: 939
From: Central Florida
2025 C7 of the Year Finalist - Modified
2024 C7 of the Year Finalist - Modified
2023 C7 of the Year Finalist - Unmodified
2019 C5 of Year Finalist (stock)
Racer
Joined: Mar 2017
Posts: 297
Likes: 67
From: Coweta, OK
