Silverado 2014+ Looking for quietest performance exhaust mod?

GMC_SD_Ult_16 · December 29, 2016

Well I could not take my 6.2L truck sounding like a prius on steroids anymore... So I went to my local muffler shop and had them delete the muffler and move the resonator to the old muffler location... I left in the flapper and glad I did... Originally I had the flapper clamped open and it sounds good but when cruising at 70mph the v4 chopper drone sound was too much to bear for me. I unclamped the flapper still keeping the nice 6.2L growl but the the v4 drone / V8 sound was quieted down nicely/almost completely for the cruising drive. It sounds slightly louder than my 2008 SD and was just about exactly what I wanted. Growl when I want it; quiet at cruising. Total cost with new twin tips $160. I know... where the pics and sound clip... I will see what I can do tomorrow. Thanks to all the forum members whos feedback I read to figure out what I thought would work best for my truck needs.

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Driver72 · December 29, 2016

Well I could not take my 6.2L truck sounding like a prius on steroids anymore... So I went to my local muffler shop and had them delete the muffler and move the resonator to the old muffler location... I left in the flapper and glad I did... Originally I had the flapper clamped open and it sounds good but when cruising at 70mph the v4 chopper drone sound was too much to bear for me. I unclamped the flapper still keeping the nice 6.2L growl but the the v4 drone / V8 sound was quieted down nicely/almost completely for the cruising drive. It sounds slightly louder than my 2008 SD and was just about exactly what I wanted. Growl when I want it; quiet at cruising. Total cost with new twin tips $160. I know... where the pics and sound clip... I will see what I can do tomorrow. Thanks to all the forum members whos feedback I read to figure out what I thought would work best for my truck needs.

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Just curious here, but what was the benefits of moving the smaller resonator after removing the large muffler? Would it not do the same job in it's original place?

GMC_SD_Ult_16 · December 29, 2016

Just curious here, but what was the benefits of moving the smaller resonator after removing the large muffler? Would it not do the same job in it's original place?

I am not sure of the logistics to cause it to sound so different but it does. I copied doing this off another forum member who swore by it. It's almost like putting on a straight through design muffler (very little sound restriction type), deleting the resonator (since I moved it to the muffler location) and leaving in the fully functional flapper to remove drone and cruising sounds.

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Driver72 · December 30, 2016

I am not sure of the logistics to cause it to sound so different but it does. I copied doing this off another forum member who swore by it. It's almost like putting on a straight through design muffler (very little sound restriction type), deleting the resonator (since I moved it to the muffler location) and leaving in the fully functional flapper to remove drone and cruising sounds.

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So how loud is it doing it that way?

I have yet to decide on how to make this 6.2 rumble a bit, but without sounding like I'm trying to make it sound like a muscle car.

GMC_SD_Ult_16 · December 30, 2016

So how loud is it doing it that way?

I have yet to decide on how to make this 6.2 rumble a bit, but without sounding like I'm trying to make it sound like a muscle car.

My 6.2 definitely has a rumble/growl on start up... Driving through my neighborhood is not going to cause any noise complaints unless I were to give it gas. On the highway when steady cruising I don't have drone & not much sound but if I gun it with others around me they will know I have something different for an exhaust. That is the best way I can describe the sound.

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ruby15z71 · December 30, 2016

My 6.2 definitely has a rumble/growl on start up... Driving through my neighborhood is not going to cause any noise complaints unless I were to give it gas. On the highway when steady cruising I don't have drone & not much sound but if I gun it with others around me they will know I have something different for an exhaust. That is the best way I can describe the sound.

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Basically the resonator was put in by GM to make the exhaust quiet. It has no other purpose but sound deadening. Removing the stock muffler and putting the resonator in its place and adding a new tail pipe is the cheapest way and best way to get good sound cheap without being too loud.

There are a few videos of it on YouTube. I personally would delete the flapper cause the sound with flapper is terrible. I am going to spend the coin and get a corsa touring I think or make my own and get 3" piping with a borla or xs.

Clo004 · January 5, 2017

My 6.2 definitely has a rumble/growl on start up... Driving through my neighborhood is not going to cause any noise complaints unless I were to give it gas. On the highway when steady cruising I don't have drone & not much sound but if I gun it with others around me they will know I have something different for an exhaust. That is the best way I can describe the sound.

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Did you leave the flapper in the original place or did you move it right behind the resonator like the other member did.

GMC_SD_Ult_16 · January 5, 2017

Did you leave the flapper in the original place or did you move it right behind the resonator like the other member did.

My flapper is located near the original location but the resonator was moved so that it is about 1 foot in front of flapper (resonator is in the original muffler location) I think the other member had resonator placed real close to the flapper but in front like mine.. From the flapper to the exhaust tips is straight pipe.

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WildCatBlack · September 6, 2018

First time Poster, just signed up,

Sorry to bring up this old thread but I have this issue with my 2018 6.2L Sierra Denali, and this is the best thread I have found so far so i signed up and hoping that my experience can help people too.

I installed an AFE cold air intake, Kooks 1 7/8" headers, Kooks Y Pipe with Green Cats, and a GMPP Borla system. happy to say that seat of the pants feel is significant, its like i went from a lazy sunday morning to a saturday after sleeping in and having a large coffee, shes ready to go!

I am addicted to performance but growing up so the noise is no longer acceptable, and there in lies the problem.

The system i have stated above is excessively loud on start up and under WOT, it also does create drone at 2000+ RPM but it is actually good at preventing helicopter in V4 which was a massive issue on my old truck (08, 6L with magnaflow) the old truck had a superior tone with no rasp, for me i'd say the magnaflow just sounds better on these engines(but that's just my opinion)

from what i can gather the stock cats make a huge difference for tone and volume, many people have been stating that the noise is from the headers but i have tested and the excess noise is absolutely cat back and not engine.

I reinstalled the stock cat back with the Kooks headers and y pipe to see if it would work for quiet it down and while it was quiet to the level that was nearly stock, it made it sound like a big V6 when revving or WOT , think ecoboost with exhaust, so the GMPP Borla went back on for now.

my next trial is going to either be a resonator pre muffler but there is very little room and my area doesn't have anyone with a mandrel shop, or a longer Magnaflow as the Borla is only 20", i likely could fit a 24 or 27" and hoping for their longer 30" and hoping it eliminates the rasp at the very least and a couple db quieter due to the length.

If anyone has any more experience with this same issue i'd love to revive this thread to get some new perspectives or opinions

Lgetz · September 12, 2018

Sorry to hear you are too loud now WildCat. I run a Magnaflow 12909 on my 2015 6.2 and it sounds good to me. Slightly deeper tone than stock, a bit louder, and even with flapper valve removed little/no drone or V4 chop.

The case is 22 inches long IIRC and the overall length made it easy for shop to weld in place of the stock muffler and flapper valve without doing a complete hack job. Might be a good choice for to run in place of the Borla muffler.

KARNUT · September 12, 2018

I have an old 5.7 stroked and blown running shorties with three inch exhaust. I have high flo cats and mufflers. To remedy the too loud I had short glass packs put on at the tail pipes with turn down s at the bumper.

The exhaust carries a deep tone through the RPM range, with back ground at cruising.

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