Muffler Delete question

Kens16Denali · December 15, 2016

For those that have done the muffler delete i have a few questions:

1. Do you still like it or do you wish you had done a muffler swap?

2. Did you leave the flapper valve or remove it? If you left it do you wish you had'nt or do you have it clamped open?

3. The longer you have had it done have you noticed any differences in mileage, sound etc....

4. the ones who have left the flapper have you tried it with the flapper clamped open? notice much difference?

I have read thru all the other post on here about it but wanted some updated information.

I have a 2016 Sierra Denali crew cab with the 5.3 and 8 speed. I currently have the flapper clamped open and have for

the last couple of months. I want to do the muffler delete but cant decide if i want to leave or remove the flapper. Seems like

it may be restrictive on the system but not sure. With it clamped open i cannot tell when it goes into V4 mode but that may change

once i have this done and looking for recommendations. I do know i can run it in M7 to keep it from going into V4 and i dont mind a

little drone but i dont want it too bad.

Thanks in advance for the help and advice.

Archaic2021 · December 15, 2016

I loved my muffler delete. I ran it until i did headers back. But...IMO if you arent willing to tune out or de-activate it its not worth it. V4 kicks in it will still sound like a helicopter is chasing you.

KARNUT · December 15, 2016

I did muffler delete on my 14, had helicopter sound. Did a hand held to turn it off, otherwise it sounded fine. From all the reading I've done here the only way to not have the helicopter sound is stock exhaust or the GM backed exhaust.

bdbake01 · December 16, 2016

Had a !muff mod since '14. BUT, I didn't just half a$$ it.

Removed muffler (obviously), moved resonator to the original muffler position. Moved flapper, unmodified, to a spot immediately after the now relocated resonator (literally 1/2" away). Added an eBay special stainless (HAHA!) Y-pipe and ran duals over the axle and out the back.

Love it. LOVE IT. It is THE perfect balance IMHO between volume and sound quality. Everyone is amazed. Exhaust dude, seasoned pro, amazed. Recommends to ALL of his clients.

No drone. NONE. NO. ZERO. Let me repeat that because I know what's coming next, I HAVE NO DRONE WHATSOEVER. PERIOD. NONE. Get my drift?

Tried strapping the flapper open, immediate drone. GM knew what they were doing. It changes the effective volume of the exhaust. Works.

Wouldn't change a G-Damn thing. Also, I'll keep that ~$800 in my pocket thank you very much.

Kens16Denali · December 16, 2016

Thanks for the info, will consider that. Any sound clips of your setup?

LTZ16 · December 22, 2016

Any pictures of your set up,, so your saying don't do the clamp thing!!!!

GMC_SD_Ult_16 · December 25, 2016

Had a !muff mod since '14. BUT, I didn't just half a$$ it.

Removed muffler (obviously), moved resonator to the original muffler position. Moved flapper, unmodified, to a spot immediately after the now relocated resonator (literally 1/2" away). Added an eBay special stainless (HAHA!) Y-pipe and ran duals over the axle and out the back.

Love it. LOVE IT. It is THE perfect balance IMHO between volume and sound quality. Everyone is amazed. Exhaust dude, seasoned pro, amazed. Recommends to ALL of his clients.

No drone. NONE. NO. ZERO. Let me repeat that because I know what's coming next, I HAVE NO DRONE WHATSOEVER. PERIOD. NONE. Get my drift?

Tried strapping the flapper open, immediate drone. GM knew what they were doing. It changes the effective volume of the exhaust. Works.

Wouldn't change a G-Damn thing. Also, I'll keep that ~$800 in my pocket thank you very much.

Following up on this as well... Any pics of the setup and a video or the sound would be great.... Looking for good low rumble sound like my stock 2008 SD had.. No drone.... And no annoying crazy loud sound when cruising around my neighborhood... We have a guy in the neighborhood that must have headers and dump straight out somewhere as it just goes through the house when he leaves the area.. Super annoying and I don't want to be that guy. Thanks.

Sent from my Note 5 using Tapatalk

bdbake01 · December 25, 2016

Don't think I have any videos, but I'll try to get some next week when I get back into town. Check my profile. I made a decent write up some time back with several pics. Sorry for not looking it up myself, on a cell phone here and possibly driving.

GMC_SD_Ult_16 · December 29, 2016

Had a !muff mod since '14. BUT, I didn't just half a$$ it.

Removed muffler (obviously), moved resonator to the original muffler position. Moved flapper, unmodified, to a spot immediately after the now relocated resonator (literally 1/2" away). Added an eBay special stainless (HAHA!) Y-pipe and ran duals over the axle and out the back.

Love it. LOVE IT. It is THE perfect balance IMHO between volume and sound quality. Everyone is amazed. Exhaust dude, seasoned pro, amazed. Recommends to ALL of his clients.

No drone. NONE. NO. ZERO. Let me repeat that because I know what's coming next, I HAVE NO DRONE WHATSOEVER. PERIOD. NONE. Get my drift?

Tried strapping the flapper open, immediate drone. GM knew what they were doing. It changes the effective volume of the exhaust. Works.

Wouldn't change a G-Damn thing. Also, I'll keep that ~$800 in my pocket thank you very much.

Bdbake01,

I wanted to thank you for the details provided on your set up. I set mine up very similar except I kept a single exit on the passenger side and added new dual tips. You were dead on about the drone with flapper clamped open. The muffler shop had not done it that way before and he totally thought it sounded better than the straight muffler deletes he had previously done. Again thanks for your information. I am super excited to have my 6.2L growl and ability to have a quiet drive at cruising speeds. Best of both worlds finally.

Sent from my Note 5 using Tapatalk

bdbake01 · December 29, 2016

Bdbake01,

I wanted to thank you for the details provided on your set up. I set mine up very similar except I kept a single exit on the passenger side and added new dual tips. You were dead on about the drone with flapper clamped open. The muffler shop had not done it that way before and he totally thought it sounded better than the straight muffler deletes he had previously done. Again thanks for your information. I am super excited to have my 6.2L growl and ability to have a quiet drive at cruising speeds. Best of both worlds finally.

Sent from my Note 5 using Tapatalk

Awesome! Very glad I could help. And thank YOU for the testimony. I've been telling people about this setup for literally years, and honestly I don't think very many have believed me. I'm not a very good salesman I guess But I can't blame them. It just doesn't seem like you should be able to get the sound of an $800 setup for ~$100 or so. Usually when someone comes on a board like this touting crazy jibberish such as that, it turns aout to be complete BS or with several strings attached. But I'm telling you, this is the real deal, and I have absolutely zero to gain by sharing this info. I just want to help others out who are looking for the same sound as I!

Enjoy!

kkmitchell5 · December 29, 2016

Awesome! Very glad I could help. And thank YOU for the testimony. I've been telling people about this setup for literally years, and honestly I don't think very many have believed me. I'm not a very good salesman I guess But I can't blame them. It just doesn't seem like you should be able to get the sound of an $800 setup for ~$100 or so. Usually when someone comes on a board like this touting crazy jibberish such as that, it turns aout to be complete BS or with several strings attached. But I'm telling you, this is the real deal, and I have absolutely zero to gain by sharing this info. I just want to help others out who are looking for the same sound as I!

Enjoy!

I see that you and GMC SD 16 have a 6.2 do you think it would have the same effect for the 5.3? I have a magna flow 18" muffler being shipped to me right now, but i am torn between doing what you guys did and just swapping the muffler out. I am for sure going to keep the flapper in no matter what. Based on what you guys did i assume the the biggest thing for drone is the resonator? Also how you have it setup does it just growl/rumble at idle and when you get after it a little bit? thanks again for the input

GMC_SD_Ult_16 · December 29, 2016

I see that you and GMC SD 16 have a 6.2 do you think it would have the same effect for the 5.3? I have a magna flow 18" muffler being shipped to me right now, but i am torn between doing what you guys did and just swapping the muffler out. I am for sure going to keep the flapper in no matter what. Based on what you guys did i assume the the biggest thing for drone is the resonator? Also how you have it setup does it just growl/rumble at idle and when you get after it a little bit? thanks again for the input

I think it would have a similar effect but not sure... Regarding the drone... When I ran the new configuration with the flapper clamped open I had fairly bad drone at 70 mph (was annoying to me) ... After unclamping the flapper and driving 70 mph it was night and day different... Very little noise in cab accept when the cruise control went up hills and needed more rpms to make it.. Even then it was a nice low rumble. I think the resonator in the new configuration becomes more of a pass through muffler without nearly as much sound deadening as the original setup. Just my 2 cents.

Sent from my Note 5 using Tapatalk

kkmitchell5 · December 29, 2016

I think it would have a similar effect but not sure... Regarding the drone... When I ran the new configuration with the flapper clamped open I had fairly bad drone at 70 mph (was annoying to me) ... After unclamping the flapper and driving 70 mph it was night and day different... Very little noise in cab accept when the cruise control went up hills and needed more rpms to make it.. Even then it was a nice low rumble. I think the resonator in the new configuration becomes more of a pass through muffler without nearly as much sound deadening as the original setup. Just my 2 cents.

Sent from my Note 5 using Tapatalk

Awesome thanks! so then with the flapper working there is no drone? Also i drive in the mountains aton, would it get annoying or to loud when running at 3k-5k rpm constantly? I know you said nice low rumble but just curious... Thanks

bdbake01 · December 29, 2016

Awesome thanks! so then with the flapper working there is no drone? Also i drive in the mountains aton, would it get annoying or to loud when running at 3k-5k rpm constantly? I know you said nice low rumble but just curious... Thanks

The key to no drone is keeping the flapper, but I also believe it's aided by having the resonator BEFORE the flapper. Reason being is that the flapper was designed to maintain two effective exhaust volumes (v4/v8), and removing the muffler takes out a TON of volume upstream of the flapper. Moving the resonator prior to the flapper restores some of this volume.

I tow a bit myself. It will get a little louder inside at 3-5k, but it isn't intrusive to me at all. And from what I can tell of other aftermarket setups, this setup is much quieter inside at those levels. And, at least to me, it's a very pleasant sound. Growl, not drone.

As for 5.3 vs 6.2, I'd expect the same results with maybe a littttle higher pitch. There just isn't as much motor barking down those pipes

GMC_SD_Ult_16 · December 29, 2016

Awesome thanks! so then with the flapper working there is no drone? Also i drive in the mountains aton, would it get annoying or to loud when running at 3k-5k rpm constantly? I know you said nice low rumble but just curious... Thanks

I have only tested it for one day so to be honest the 3 to 5k rpms range I am not sure about... In that range you will hear the sound loud and clear... As those rpms will for sure open up the flapper and let out the sound. It depends on your acceptance level of sound and unfortunately everyone's level on this forum seems to have a wide range of acceptance. My sound with straight cruising and flapper unclamped is slightly above stock but not annoying or a drone to me.

Sent from my Note 5 using Tapatalk