Muffler Only Replacement Questions

Sierra Jon · October 17, 2016

I am looking at doing the exact same system on my truck. I want the nice throaty sound without being to loud. When your cruising do you notice your exhaust to much?

Hardly at all. As most have stated the V4 is louder with the valve pinned open but it's not noticeable unless you're looking for it. My wife didn't notice at all. It sounds much better than stock but still very quiet. I'm thinking of taking the resonator out too.

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SilentSierra · October 18, 2016

2015 Sierra 5.3

I just installed a 22" magnaflow SI/SO offset and had the flapper valve removed. There is a very minimal change in sound...possibly a little deeper tone at times. I'm assuming it's the factory resonator absorbing the sound. I've read a lot of different threads on here and the videos are all a little misleading. I'm debating changing the 22" for and 18" magnaflow. Has anyone installed an 18" with the factory res? Would that help with the chopper noise?

Sierra Jon · October 20, 2016

2015 Sierra 5.3

I just installed a 22" magnaflow SI/SO offset and had the flapper valve removed. There is a very minimal change in sound...possibly a little deeper tone at times. I'm assuming it's the factory resonator absorbing the sound. I've read a lot of different threads on here and the videos are all a little misleading. I'm debating changing the 22" for and 18" magnaflow. Has anyone installed an 18" with the factory res? Would that help with the chopper noise?

Going from a 22" mag to an 18" mag is going to enhance the chopper noise slightly but it should be a little louder.

22" is pretty long. My Borla is 14" and it's still pretty tame.

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SilentSierra · October 20, 2016

Going from a 22" mag to an 18" mag is going to enhance the chopper noise slightly but it should be a little louder.

22" is pretty long. My Borla is 14" and it's still pretty tame.

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Well, I did it. I had them install the 18" (leaving the resonator on)...drove it around town a little. Definitely more sound and I probably would have been satisfied with it. I went back and had them remove the resonator and I really like it. Yes, there is a little drone and slight chopper noise (very little) but it's nothing I wouldn't have expected by putting an aftermarket muffler on. We do this to get a better, tougher sound out of our V8's right!!!!

Sierra Jon · October 20, 2016

Well, I did it. I had them install the 18" (leaving the resonator on)...drove it around town a little. Definitely more sound and I probably would have been satisfied with it. I went back and had them remove the resonator and I really like it. Yes, there is a little drone and slight chopper noise (very little) but it's nothing I wouldn't have expected by putting an aftermarket muffler on. We do this to get a better, tougher sound out of our V8's right!!!!

Yea i was sick of my truck sounding like a Prius. After the muffler and drop in aem filter in getting at least 1mpg better around town.

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Jp sierra · December 28, 2017

I recently swapped my stock muffler (flapper included) with a magnaflow muffler I purchased at pep Boys for under $90... I’m literally at the muffler shop reinstalling my factory one back on... don’t get me wrong the magnaflow sounded great until it went into V4 mode... I could not take it anymore that helicopter sound was so unsatisfying... so I’ll wait till I can get the gm performance borla cat back..

reardiff · December 28, 2017

Been following this topic as I've been thinking of an exhaust as well. What is the overall sound difference between 5.3 and 6.2? Most seem to have the 5.3, but curious if the 6.2 sounds any different with any of these choices?

Lgetz · December 28, 2017

I have a Magnaflow 12909 without flapper valve but kept the resonator on my 6.2 and it sounds good. Slightly louder, deeper tone under throttle, nice rumble at startup and idle, amazing at wide open throttle. Minimal/no drone at cruise and minimal/no V4 chop. One of the best bang for the buck mods IMO. Best part is a competent exhaust shop can cut stock muffler and flapper valve and replace with ease. Another similar option is a Flowmaster 53553 but cost is higher.

Jp sierra · December 28, 2017

5 hours ago, Jp sierra said:

I recently swapped my stock muffler (flapper included) with a magnaflow muffler I purchased at pep Boys for under $90... I’m literally at the muffler shop reinstalling my factory one back on... don’t get me wrong the magnaflow sounded great until it went into V4 mode... I could not take it anymore that helicopter sound was so unsatisfying... so I’ll wait till I can get the gm performance borla cat back..

Ok what a difference ... no chopper sound anymore , I left the resonator off so with that and my airaid MIT with a K&n drop in filter is good enough for me.. still has that rumble at WOT but no V4 chopper drone.. it’s all a matter of what your willing to live with ...gm performance borla (dealer item) includes the flapper on its muffler , so it’s there for a reason... but pricy$$$

michigan2500hd · December 29, 2017

So, is there no way to put a nice somewhat louder aftermarket muffler/cat back system that doesn't sound weird in V4 mode? I just bought the truck Saturday, so I am not sure I am ready to do away with the AFM just yet.

I cut out the factory muffler, installed a 22" Magnaflow but left the valve and resonator. No v4 chop at all. It's too quiet for me though so I pinned the flapper open and it sounds mean plus no v4 noise but still too quiet. I ordered the 3.5 " MBRP cat back ( installer seires). Can't wait for warm enough weather to get it on.

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Krusty · December 29, 2017

6 hours ago, Jp sierra said:

I recently swapped my stock muffler (flapper included) with a magnaflow muffler I purchased at pep Boys for under $90... I’m literally at the muffler shop reinstalling my factory one back on... don’t get me wrong the magnaflow sounded great until it went into V4 mode... I could not take it anymore that helicopter sound was so unsatisfying... so I’ll wait till I can get the gm performance borla cat back..

That is sure a sideways muffler shop U go to..................

Remember around town V-4 chop can be avoided my running in manual mode in 7th gear............... I most def can hear a slight chop - but the wife and others do not notice............... Flowmaster 50 series big block (the "quietest" muffler they offer)............ problematic flapper gone - kept the resonator..........