Removing only the last resonator in the exhaust?

Ozer · May 8, 2019

Flapper is welded inline with the muffler, its right after the muffler and its purpose is to basically restrict the flow of exhaust gasses when the truck is in V4 mode to mimic a smaller diameter exhaust pipe.

If you are all stock, leave it in.. if you turn V4 off and leave exhaust stock, leave it in since it will always stay open. If you get aftermarket muffler and dont turn off V4, remove it so that you dont get the chopper noise.

Aftermarket muffler with V4 ON and no plapper gives you the chopper noise.

Profanesix · May 9, 2019

I just went through a small process of this. I simply removed the rear resonator. It did add some low tone to make it sound like a V8. but only from cold start and with revs to about 1500 RPM. So I went with a Carven TR muffler. They left the flapper installed, and I instantly got the flapper chatter and rattle. Anytime the engine was under load I could hear the flapper over the exults it was crazy. SO. long story short, and as most people have stated, if you want a nice sounding truck with zero issues. Get an aftermarket muffler, even ones that are not as loud, remove flapper, and get a Range AFM disabler. My truck sounds amazing ( a little loud for what I was looking for, but it has the deep low tone). the Range will simply bring your truck to life and get rid of the shifting issues related to V4 bouncing back and forth as well as keeping the drone away.

Mileguru · May 9, 2019

8 hours ago, Ozer said:

If you get aftermarket muffler and dont turn off V4, remove it so that you dont get the chopper noise.

You meant DON'T remove it so you can avoid the chopper noise.

Aftermarket muffler + V4 ON needs the flapper still.

Interesting note, I zip-tied my flapper open and got a little more exhaust note as expected, but what was unexpected was the improvement in trans shifting. I had some of the typical hard 1-2 shift with my 8-speed, but now it happens much less often (and when it does happen, it doesn't bang into 2nd so hard).

mulage · May 10, 2019

i tried the Range device, my truck did not like it

it made the trans shift hard/ weird

Forace2018 · May 31, 2019

On 5/8/2019 at 8:53 AM, Forace2018 said:

I just bought in December 2018 a 2018 GMC Sierra 1500 ccsb with the 6.2 8spd. I am surprised how good this truck sounds with just a cold air intake. I also am not looking for much louder sound but I have tuned out the AFM/DOD so that is no problem anymore. I am going to leave stock muffler on, take out the flapper and put a Y pipe in and go out back with duals and 3 1/2 16inch long chrome tips. I should have a little deeper sound but hope no drone with this.

Update, just did what I said, took out flapper, added Y pipe and duals out back with 3 1/2 inch 16 inch long stainless tips, sounds deep but not too loud so It did what I wanted, still fairly quiet untill i get into it! Puts big smile on my face. Hope this helps!

Mileguru · June 2, 2019

On 5/31/2019 at 10:12 AM, Forace2018 said:

Update, just did what I said, took out flapper, added Y pipe and duals out back with 3 1/2 inch 16 inch long stainless tips, sounds deep but not too loud so It did what I wanted, still fairly quiet untill i get into it! Puts big smile on my face. Hope this helps!

You cut out the resonator, right? How loud is it on a cold start and warm start?

Forace2018 · June 2, 2019

7 hours ago, Mileguru said:

You cut out the resonator, right? How loud is it on a cold start and warm start?

Yes took out resonator. Just a little louder but not enough to wake anyone up. Cruising is still mostly quiet but with a cold air intake on it, that 6.2 sounds really good when you get into it. No drone . Sort of a sleeper, quiet when you want it and a deep sound when you ask for it! Hope this helps.

Mileguru · June 2, 2019

2 hours ago, Forace2018 said:

Yes took out resonator. Just a little louder but not enough to wake anyone up. Cruising is still mostly quiet but with a cold air intake on it, that 6.2 sounds really good when you get into it. No drone . Sort of a sleeper, quiet when you want it and a deep sound when you ask for it! Hope this helps.

Thanks! No matter what I do, I'll delete the flapper because I'm supercharged and tuned out AFM. But I can't then decide between:

1) Just delete muffler and replace with pipe

2) Replace muffler with an aftermarket muffler

3) Or just delete the resonator like you did

I want to increase the rumble just a little bit, not have LOUD startups, not have obnoxious drone in town or highway, and increase the airflow. Strangely for me, when I zip tied the flapper open, my 8-speed started shifting a little better (still not perfect, but a little better). The 1-2 and 2-1 clunk is not as hard and not as often.

Forace2018 · June 2, 2019

8 hours ago, Mileguru said:

Thanks! No matter what I do, I'll delete the flapper because I'm supercharged and tuned out AFM. But I can't then decide between:

1) Just delete muffler and replace with pipe

2) Replace muffler with an aftermarket muffler

3) Or just delete the resonator like you did

I want to increase the rumble just a little bit, not have LOUD startups, not have obnoxious drone in town or highway, and increase the airflow. Strangely for me, when I zip tied the flapper open, my 8-speed started shifting a little better (still not perfect, but a little better). The 1-2 and 2-1 clunk is not as hard and not as often.

Of course I had to get rid of the flapper. I have been in town a lot as well as on highway and no drone anywhere with this setup. Stock muffler with y and stainless big tips are just right for me. Even the wife has not said anything but her son did! He liked it. So far I only have 4650 miles on her so tranny been doing ok so far. This 6.2 is an awesome motor, wish I had done this a long time ago. I bet the supercharger is crazy strong. Would love to drive one some day. Take care and hope this helps.