Muffler delete???
Thread Starter
Heel & Toe
Joined: Aug 2012
Posts: 18
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Yea after further research I agree that is definitely not the sound I want to be associated with me or any of my cars. I mean its not that I'm short on cash and can't afford the exhaust system, I just didn't want to buy a system and then it be useless after the cam swap. But now that I've heard some cammed cars and their setups I think ill just go ahead with the borla system I always use. I know I love that sound already... and at the time of the cam swap I'm going with Stainless Works LTs with cats, and at that point if its too loud ill go from there. I was just wondering in the beginning because on the ctsv it actually sounded pretty good, but I see now, well, I agree with you and spinmonster. Thanks for your input!
Thread Starter
Heel & Toe
Joined: Aug 2012
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To you killerc6, I may have asked a fairly unorthodox question, but I am no c6 rookie. I've built and owned quite a few of them. From time on the dyno I can tell you a quality exhaust system will most definitely provide a noticeable power gain. The heads in the c6 are actually really good and it seems like the cam and exhaust are the two most power limiting factors. I've never used any OBX products but I do know American racing, stainless works, and kooks products as far as headers go will all increase the power output of your car. Honestly, with a good tune and a good intake/exhaust setup you can see upwards of 30-40hp gains. Throw in a cam and retune it and you can normally look for another 30-40hp. In my experience at least. Someone please correct me if my statements are invalid.
Tech Contributor
Joined: Mar 2003
Posts: 12,094
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From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
Headers on the other hand are a gain of 30-35hp for the best systems. This assumes you get expensive metal matrix cats and a 3" x-pipe. No cats is 10rwtq....not much in HP and smell bad.
The Z06 mufflers flow really well and can be opened or closed depending on sanity requirements.
Tech Contributor
Joined: Mar 2003
Posts: 12,094
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From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
Moderately big cams like a 230/234 114+2 gains 60rwhp....sometimes a bit more depending on other mods and if its a LS2 or 3
Thread Starter
Heel & Toe
Joined: Aug 2012
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I would agree with that, just didn't want to overexaggerate that gain. I have a buddy with a cammed c6 and after exhaust intake mods, just the cam swap and tune netted about 53rwhp. So I definitely agree that 60rwhp from a cam is attainable.
Tech Contributor
Joined: Oct 1999
Posts: 41,032
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From: Charlotte, NC (formerly Endicott, NY)
I was a supporting tuner on this forum and do installs at a shop. I have been through this with dozens of corvettes. If your only lokking for opinions that support what you want to hear then you werent looking for opinions but rather someone to affirm what youre already going to do.
It has serious drone in the car at all RPM's and it gains no power. I heard every exhaust system, dyno'ed every combo you can think of and its noise with no power gain.
Even people who got the STS turbo kit with cats intact cant take the drone and change out the kit. The turbos on that kit replace the mufflers so they act as a muffler. Im just relaying what I've witnessed many times over. I should point out that a cam is the biggest variable here. A big cam with no mufflers will be way louder. Many people who are fine with an aftermarket exhaust are pushed over their limit once they cam the car. I ran a Z06 exhaust on my car (959rwhp) and with the cuttouts open it was offensive.
If you liked it on a CTS then you will likely be fine with it on a covette. I dont like loud but then I'm also relaying many other's people discomfort with the mod. Police arent going to like it either. I was one of them too. You may just be one of those guys who like cherry bomb mufflers or open headers, in which case I cant speak for you. Im just trying to keep people from making the swap and then going back to a NPP exhaust after they had enough drone on the hiway. Its your money.
It has serious drone in the car at all RPM's and it gains no power. I heard every exhaust system, dyno'ed every combo you can think of and its noise with no power gain.
Even people who got the STS turbo kit with cats intact cant take the drone and change out the kit. The turbos on that kit replace the mufflers so they act as a muffler. Im just relaying what I've witnessed many times over. I should point out that a cam is the biggest variable here. A big cam with no mufflers will be way louder. Many people who are fine with an aftermarket exhaust are pushed over their limit once they cam the car. I ran a Z06 exhaust on my car (959rwhp) and with the cuttouts open it was offensive.
If you liked it on a CTS then you will likely be fine with it on a covette. I dont like loud but then I'm also relaying many other's people discomfort with the mod. Police arent going to like it either. I was one of them too. You may just be one of those guys who like cherry bomb mufflers or open headers, in which case I cant speak for you. Im just trying to keep people from making the swap and then going back to a NPP exhaust after they had enough drone on the hiway. Its your money.
on the loudness. Doing this on a CTSV is totally different than a Corvette. The Caddy has a lot more noise insulation than the Vette and the exhaust exit is close to 4 ft further away from your ears than in the Corvette. I did this on my C5 and the drone was tremendous. There were things vibrating in the cabin that didn't vibrate before I put the pipes on and they stopped vibrating when I put mufflers back on the car. At highway speeds in 6th gear I couldn't hear the radio unless it was turned all the way up and if I had a passenger I couldn't talk to them without yelling.Bill
Tech Contributor
Joined: Mar 2003
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From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
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Intermediate
Joined: Sep 2011
Posts: 26
Likes: 0
From: Gainesville va
Isn't the NPP muffler pretty much a straight pipe/muffler delete when it's in bypass mode? From the looks of the Z06 guys muffler mod, that's what i always thought. So, how much louder would a straight pipe be?
Racer
Joined: Feb 2009
Posts: 425
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From: Diamondhead Mississippi
My friends c6 has the muffler delete and a resonator welded in an has no drone. It's not terribly loud and it sounds great at wot. I guess everyone's opinions are different but I can't see how anyone would see his car as intolerable.
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,106
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
Both the Z06 and NPP mufflers have a 2.5" inlet and a 2.25" exit. Just the size reduction alone will create more backpressure to quiet the sound.
Racer
Joined: Jan 2001
Posts: 357
Likes: 2
From: San Diego ,CA, USA
I don't chime in often but I will here.
A co-worker removed his C6 muffs on his 2007 LS2, no other mods worth mentioning (no headers or cam). I honestly can tell you it is not much louder in the cabin to my ears, does sound a lot meaner but not so much louder. Outside it is noticeably louder but not going to bother anyone especially if not WOT.
He says he gets some drone but claims it never bothers him. I don't ride in it often, just several times since he removed them a few years ago.
YMMV.
But what a simple mod to reverse if you don't like it. There is little profit to be had, thus the reason the muffler manufacturers don't offer it as a product.
A co-worker removed his C6 muffs on his 2007 LS2, no other mods worth mentioning (no headers or cam). I honestly can tell you it is not much louder in the cabin to my ears, does sound a lot meaner but not so much louder. Outside it is noticeably louder but not going to bother anyone especially if not WOT.
He says he gets some drone but claims it never bothers him. I don't ride in it often, just several times since he removed them a few years ago.
YMMV.
But what a simple mod to reverse if you don't like it. There is little profit to be had, thus the reason the muffler manufacturers don't offer it as a product.
Drifting
Joined: Feb 2012
Posts: 1,255
Likes: 66
From: San Luis Obispo, California
I didn't know this..that the Z06 factory cat-back system & the LS3 NPP cat-back system each have a 2.5" inlet & a 2.25" outlet...really? Interesting...I would've though the C6 Z06 system would've stayed 3" all the way out...
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,106
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
The NPP has 2.5" all the way into the muffler, but also has the same exit.
It's been a while since I cut off some of the base tips, but I'd suspect they would also use the 2.18" OD pipe for the muffler exit.
Thread Starter
Heel & Toe
Joined: Aug 2012
Posts: 18
Likes: 0
I don't chime in often but I will here.
A co-worker removed his C6 muffs on his 2007 LS2, no other mods worth mentioning (no headers or cam). I honestly can tell you it is not much louder in the cabin to my ears, does sound a lot meaner but not so much louder. Outside it is noticeably louder but not going to bother anyone especially if not WOT.
He says he gets some drone but claims it never bothers him. I don't ride in it often, just several times since he removed them a few years ago.
YMMV.
But what a simple mod to reverse if you don't like it. There is little profit to be had, thus the reason the muffler manufacturers don't offer it as a product.
A co-worker removed his C6 muffs on his 2007 LS2, no other mods worth mentioning (no headers or cam). I honestly can tell you it is not much louder in the cabin to my ears, does sound a lot meaner but not so much louder. Outside it is noticeably louder but not going to bother anyone especially if not WOT.
He says he gets some drone but claims it never bothers him. I don't ride in it often, just several times since he removed them a few years ago.
YMMV.
But what a simple mod to reverse if you don't like it. There is little profit to be had, thus the reason the muffler manufacturers don't offer it as a product.
Advanced
Joined: Jun 2012
Posts: 89
Likes: 3
From: Zimmerman MN
Not sure what this guy has, but it gets loud! He goes WOT about halfway through the vid.
http://youtu.be/6vAquo3yp6s
http://youtu.be/6vAquo3yp6s
Le Mans Master
Joined: Oct 1999
Posts: 8,205
Likes: 40
From: Tucson AZ
. I'm excited. You only get drone at low RPMS.
Instructor
Joined: Jan 2014
Posts: 183
Likes: 2
From: Texas
I completely agree. It does sound as quiet as a Saturn. This is by far the quietest vehicle I've ever had. I picked up an SLP LM1 and god I hope it makes a difference. If not I'm headers are next sooner than latter this year. A co-workers v6 mustang has more sound than my vette. I just don't think it could ever get too loud. My daily driver is L92 Denali with Dynatechs, highflow cats and a cherrybomb 3.5 SI/SI before the rear tire. That's loud. My vette, needs to be louder than that. I almost removed the stock axel back and drove like that but it seems it would look weird without the tips.
Last edited by D.Guerra; Feb 26, 2014 at 04:52 AM.