Suitcase muffler delete/replacement

[DWSmoot]

I am seriously considering doing just a muffler swap on mine. Magnaflow 12259. I had one on my 2017 and loved the low, not obnoxious sound, and no drone. I also deleted the flapper valve on my 17 when I changed mufflers.

Does anyone know if there is anything different I need to know about on the 2021's vs. 2017's? I have tried to do some research but kind find much out about these new ones yet.

I had a guy at local shop crawl up under it today (lift was occupied) and he said he did not see a flapper valve from angle he was looking, but could be tucked up out of easy view.

Thanks in advance for the help.

 

[Bigmanny]

MY 6.2 has a flapper on both sides of the muffler. If you look at my pic in previous post it is even stamped "adaptive Valve". My understanding is that 19-20 Sierra and Silverado only have it on the Egress side toward the back of the vehicle. My 16 Yukon Denali also had 1 flapper valve. Borla actually made a catback for for GM that had the valve to reduce drone.

See old post
https://www.tahoeyukonforum.com/threads/performance-exhaust-which-to-buy.80018/page-4

https://www.tahoeyukonforum.com/threads/2017-yukon-denali-gm-performance-exhaust-question.118669/

 

[DWSmoot]

MY 6.2 has a flapper on both sides of the muffler. If you look at my pic in previous post it is even stamped "adaptive Valve". My understanding is that 19-20 Sierra and Silverado only have it on the Egress side toward the back of the vehicle. My 16 Yukon Denali also had 1 flapper valve. Borla actually made a catback for for GM that had the valve to reduce drone.

See old post
https://www.tahoeyukonforum.com/threads/performance-exhaust-which-to-buy.80018/page-4

https://www.tahoeyukonforum.com/threads/2017-yukon-denali-gm-performance-exhaust-question.118669/

thanks Bigmanny. Yeah, I actually talked to Norcal e few years ago and after hearing what I was looking for he recommend the Magnaflow 12259 with flapper delete. I am trying to duplicate the sound on my 2021. I experienced no drone on previous with that setup. I may be overthinking it, but just not sure if things are any different on these new ones or will have other effects of computer, etc.

What did you decide to do?

 

[DWSmoot]

I cant even find a website to look up parts for the 2021's

 

[d0wnShifT]

Wired the valve on my Tahoe tonight and it made a difference. A little louder at part throttle low rpms and didn't notice any drone at highway speeds.

 

[DWSmoot]

Wired the valve on my Tahoe tonight and it made a difference. A little louder at part throttle low rpms and didn't notice any drone at highway speeds.

Nice. Are your plans to do anything else to the exhaust?

 

[d0wnShifT]

Nice. Are your plans to do anything else to the exhaust?

Once Borla gets their system together i'll probably go with them.

 

[Bigmanny]

Once Borla gets their system together i'll probably go with them.

Did you notice a second valve on the other side of the muffler? This looks like the ingress side. Any info what I need to do to wire mine?

 

[Bigmanny]

May have answered my own question here. 6.2 = 2 valves and the 5.3 has one.

https://www.gm-trucks.com/forums/topic/221760-exhaust-flapper-vales/page/2/#comments

 

[d0wnShifT]

Did you notice a second valve on the other side of the muffler? This looks like the ingress side. Any info what I need to do to wire mine?

Only one front side of the muffler. You just need to rotate the valve clockwise and find a way to secure it if you want it open all the time.