Muffler Delete Flapper Question

tjd2003 · January 26, 2017

Hello all. I'm planning on doing the muffler delete very soon and I'm debating whether I should remove the flapper too or just clamp it open. I'll be using the Range AFM module so no V4 to worry about. What's everyone's opinion on this?

O_J_Simpson · January 26, 2017

Go for it! If you going to do it, why stop half way?

emeryz28 · January 26, 2017

if you have the V4 mode tuned out, then remove the flapper. If you do not, leave flapper.

GMC_SD_Ult_16 · January 26, 2017

I just went through the muffler delete process. For me it sounded good/deep but it was loud with flapper clamped open and any accleration. On idle it had a good clean rumble. The unclamped flapper made a strange flutter sound so I had to remove. It was loud enough my wife and neighbors could hear me come from slightly down the street and on highway you definitely had more cabin rumble noise even without v4. So I removed flapper and resonator also and added back in a Magnaflow 12909 22" muffler. This seems to be more my style. Nice low growl, calm in the neighborhood, but nice when you lay into it, I barely have any v4 chopper noise with this setup. Everyone on this forum has a different level of what is acceptable sound and for some it will never be loud enough. To note as well I have an AFE CAI on the truck and feel it does add to the sound as well. Keep that in mind if you plan to upgrade your intake as well. Good luck on finding your sound.

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Crstfr · January 26, 2017

"Everyone on this forum has a different level of what is acceptable sound and for some it will never be loud enough."...

Well said GMC_SD!...

Edited January 26, 2017 by Crstfr

tjd2003 · January 27, 2017

Had it done this morning. Had them remove the muffler and flapper and left everything else the way it was. Sounds amazing in my opinion! It's exactly what I was looking for. Thanks everyone for the input.

15_silverado · January 28, 2017

Had it done this morning. Had them remove the muffler and flapper and left everything else the way it was. Sounds amazing in my opinion! It's exactly what I was looking for. Thanks everyone for the input.

You should post a video so we can hear it?

Darth_Vader · January 29, 2017

Did you leave the resonator?

tjd2003 · January 30, 2017

I did leave the resonator. Removed the muffler and flapper and put a straight pipe in place of them. I can't say enough how much I am pleased with this. I'll try to get a video up soon.

Kens16Denali · January 30, 2017

I did leave the resonator. Removed the muffler and flapper and put a straight pipe in place of them. I can't say enough how much I am pleased with this. I'll try to get a video up soon.

How is the interior sound? how about when it switches to v4?

Barbarrino · January 30, 2017

if you have the V4 mode tuned out, then remove the flapper. If you do not, leave flapper.

Bam. Lock the thread haha.

My friend owns a muffler shop so I tried 4 different configurations and this is 10000% accurate.

tjd2003 · January 30, 2017

Bam. Lock the thread haha.

My friend owns a muffler shop so I tried 4 different configurations and this is 10000% accurate.

This is true!

tjd2003 · January 30, 2017

How is the interior sound? how about when it switches to v4?

Interior sound is mild. It sounds about the same as the stock exhaust on my wife's 07 Yukon Denali with the 6.2. For some reason GM decided these newer vehicles needed to be quiet. I felt like I needed to undo that haha. Under normal driving its barely louder than stock inside. Under acceleration you can definitely hear it. I installed the Range AFM module to turn the V4 mode off. When it switched to V4 it sounded terrible, but I removed the flapper with mine as well.