Suitcase muffler delete/replacement

[DWSmoot]

Swapping out the muffler Tomorrow with Magnaflow 12259 and defeating the flaper valve. Anyone know the outlet pipe size an the tip. Going to be adding an exhaust tip and when measuring I am Seeing either 2 3/4” or 2 7/8”?

 

[Bigmanny]

All right I am thinking about doing the Magnaflow 12909 as that seems to be pretty popular with the 19-20 Sierra/Silverado guys. I am going to keep at least 1 flapper or maybe both as I don’t want drone. The pickup guys still have some issues with drone even though the bed should not resonate like our cargo area. I am not looking for anything crazy just would like me truck to have little bit of a deeper growl. Again, my 2016 Yukon Denali sound pretty good stock with the 6.2L.

DWsmoot keep us in the loop on how things go today. You may want to retain flapper?

https://www.magnaflow.com/products/...eroffset-straight-through-performance-muffler

Swapping out the muffler Tomorrow with Magnaflow 12259 and defeating the flaper valve. Anyone know the outlet pipe size an the tip. Going to be adding an exhaust tip and when measuring I am Seeing either 2 3/4” or 2 7/8”?

 

[DWSmoot]

Going on as we speak. I deleted the 1 flapper (5.3). In and out are exact match and just a small Piece of 3” pipe to replace the area where the flapper was. Ran the same set up on my 2017 and loved it. Fingers crossed. Will update once complete.

 

[Bigmanny]

View attachment 255914 Going on as we speak. I deleted the 1 flapper (5.3). In and out are exact match and just a small Piece of 3” pipe to replace the area where the flapper was. Ran the same set up on my 2017 and loved it. Fingers crossed. Will update once complete.

View attachment 255913

Hey bud what is what with that resonator at the back? mine has one on each side.

 

[DWSmoot]

Yes. Did not delete those. Got some videos but trying to figure how to upload the LARGE files.

 

[DWSmoot]

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[DWSmoot]

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[DWSmoot]

Pretty happy with the results. Very similar to previous set up on 2017. Low rumble and wakes up on acceleration. No drone in cabin noticed. Does make a difference with the 10 speed and the extra shifts tho.

 

[Bigmanny]

sounds good. any highway dam drone noticeable yet?

 

[DWSmoot]

sounds good. any highway dam drone noticeable yet?

No none that I have noticed. At the higher cruising gears it is virtually undetectable.

There is a minor "pulsating" in some minor instances at mid gear after accelerating then letting off throttle when dropping to lower gear (which gear I am not clear on)....maybe for 1 to 2 seconds max. For me its not a big deal because it is very brief and only happens maybe 20% of the time in that situation. Sorry if unclear, hard to describe in words. Not sure if it is due to the 10 speed, maybe. Other than that no issues.