Exhaust with no drone?

Lgetz · December 4, 2015

Not sure how the 6.2L is...I would suggest calling a local muffler shop or post up a thread here specifically asking that question.

For 6.2 I recommend the 12909 which is a 3.5 inch ID/OD muffler. I have had this on both my previous 14 AT 6.2 and current 15 AT 6.2 and am very pleased. Slight hint of helicopter sound around 60 mph and have little/no drone at all. Very good sounding at startup and sounds deeper than oem exhaust.

moosehead1 · December 4, 2015

Is the helicopter sound folks are referring to from the flapper, and drone (resonance) a separate issue?

If so, does the flapper's function cut down on drone in V4 cylinder deactivation, but otherwise become the copter liability when doing resonator swaps or delete?

Please and thanks.

6D9 Matt · December 4, 2015

For 6.2 I recommend the 12909 which is a 3.5 inch ID/OD muffler. I have had this on both my previous 14 AT 6.2 and current 15 AT 6.2 and am very pleased. Slight hint of helicopter sound around 60 mph and have little/no drone at all. Very good sounding at startup and sounds deeper than oem exhaust.

Are the pipes connecting to the muffler 3" or 3.5" on the 6.2s?

Lgetz · December 4, 2015

3.5 inches. The shop I used measured the Magnaflow and used a Sawzall to cut off the oem muffler and flapper valve. They then used TIG welder to put on new muffler. Did not need pipe extension, expand pipes or crimp them to make it work. Install was nice and clean IMO and for a little under $160 a very good mod to make. Robvas has same muffler on his 6.2 so he can chime in.

6D9 Matt · December 4, 2015

The 14" MF was my plan as well, although I noticed I had written down part # 12229 rather than # 11229. I looked it up and here is the difference:

12229 - offset inlet, center outlet

11229 - center inlet, offset outlet

So which is better fitment for my application? I have a '15 6.2 Denali.

Actually, I also see now that 12229 is a 5" x 8" body diameter whereas the 11229 is 4" x 9". Is this going to make that much of a difference in sound?

Sierra Jon · December 11, 2015

Anyone have the part number for the 5.3 mufflers? I think they are 2.5" or 3"... I'm debating between 14", 18" and 22" magnaflow but according to the website the only 18" is dual out (when I punch in make and model).

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kennerz · December 12, 2015

I would try to run the magnaflow 3.5 in out 5x8 race muffler. center in out. Will give you the max power increase and somehow that open core is relatively quiet, & increases scavaging. Only really performance option outside of possibly the carven.

GPGuy · December 13, 2015

Anyone have the part number for the 5.3 mufflers? I think they are 2.5" or 3"... I'm debating between 14", 18" and 22" magnaflow but according to the website the only 18" is dual out (when I punch in make and model).

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I don't remember the part number right off of the top of my head but there is definitely a 14" 3" in 3" out Magnflow... Keep in mind that the 14" is body length only.

BigBlueLB756 · December 24, 2015

Just thought I'd mention Jones/AeroTurbine mufflers. Here's some info vids and a source.

http://www.ebay.com/itm/Jones-Full-Boar-3-Turbine-Performance-Exhaust-Jt3030XL-Universal-Muffler-/171699889393?hash=item27fa1c64f1:g:TM4AAOSwstxU8Jmu&vxp=mtr

http://www.jonesexhaust.com/products.cfm?ProductTOC=24

This is just for info ONLY.

Willshire · December 24, 2015

Gm borla dual side exit. Had gm swap it before I picked up the truck. Took the stock one home in my old truck. Very acceptable sound

ProModMike · December 28, 2015

With a fairly strong understanding of sound resonance, flow regimes and all that jazz, I looked into the flow mechanics of the GM Borla system and there IS significant effect from relocating the "flapper valve" upstream of the muffler. The stock muffler is actually fairly free flowing however, it creates turbulent or "dirty" flow downstream which the flapper valve helps to smooth out and is cleaned up by the resonator. Now, from what I can tell, and I used software that certainly wasn't designed for this application, but still similar, having the flapper valve upstream of an even MORE free flowing system helps to smooth the flow and control the velocity BEFORE it has a chance to become turbulent and create vibration, which in turn creates unwanted noise. Hence why Dynomax attempted to create a similar effect inside their VT muffler. I think I'm going to try an oval Magnaflow WITHOUT the resonator but moving the flapper valve upstream of the muffler. My goal is mimic the outcome of the GM Borla system. I want noise when I'm to the wood, wanna hear it idle, but don't want to hear a steady subwoofer racket on the freeway. I'm not overly worried about V4 mode as my truck is lifted 7" on 35's and, well, pretty much never sees V4 as a result. If anyone would like to suggest a Magnaflow that would be best, I'll give it a try and report back and try and use instrumentation during a video to produce real, measurable outcomes. I will be installing V-band flanges up and downstream of the muffler so I can install different mufflers to experiment. This venture will be subsidized by a local outfitter who wishes to be able to better tailor what its customers get. Meaning, they get a LOT of guys/gals coming through their doors every day asking for the same things as many of you, myself included, but don't want to shell out $1k+ for a catback system. So, we're going to try these theories out with about 4-5 different mufflers and record the results on video as well as with sound metering equipment for some unbiased results.

ProModMike · December 29, 2015

Can anyone suggest a couple Magnaflows? So far I only have the 12229/14229 on my radar. The goal is like I said above, remove the resonator, replace the muffler and relocate the flapper valve to achieve some startup rumble, WOT holler, but not rattle your fillings out on the freeway. We want to see how many, if any, of the Maganflows will do this using the above configuration.

Edited December 29, 2015 by ProModMike

Ryan698 · January 5, 2016

Correct. I ran the 18 on mine and loved it. Subtle while on the highway and towing but when you got on it she would talk.

Do you have a part number for the muffler and did you go cat back I think this will be the setup I try. And you went no flapper and res delete also what pipe size did you run

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Ryan698 · January 5, 2016

***UPDATE***

I put on the 18" magnaflow today and it sounds great. Just what I was looking for. Although right when it came out of the shop it sounded almost like stock. I drove the truck for about 30 (admittedly heavy footed) and I could already tell a difference in sound. I could also smell the baffling start to burn. It has a nice low rumble and opens up when I get on it. Perfect. Also, and most importantly to me, little to no drone so far. Couldn't be happier thus far.

I want to do this, what's the part number for the muffler and what size pipe did you use is this a cat back or did you swap muffler and just delete the resonator and flapper? And id it's a cat back style did you make the pipe larger

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abager2 · January 25, 2016

With a fairly strong understanding of sound resonance, flow regimes and all that jazz, I looked into the flow mechanics of the GM Borla system and there IS significant effect from relocating the "flapper valve" upstream of the muffler. The stock muffler is actually fairly free flowing however, it creates turbulent or "dirty" flow downstream which the flapper valve helps to smooth out and is cleaned up by the resonator. Now, from what I can tell, and I used software that certainly wasn't designed for this application, but still similar, having the flapper valve upstream of an even MORE free flowing system helps to smooth the flow and control the velocity BEFORE it has a chance to become turbulent and create vibration, which in turn creates unwanted noise. Hence why Dynomax attempted to create a similar effect inside their VT muffler. I think I'm going to try an oval Magnaflow WITHOUT the resonator but moving the flapper valve upstream of the muffler. My goal is mimic the outcome of the GM Borla system. I want noise when I'm to the wood, wanna hear it idle, but don't want to hear a steady subwoofer racket on the freeway. I'm not overly worried about V4 mode as my truck is lifted 7" on 35's and, well, pretty much never sees V4 as a result. If anyone would like to suggest a Magnaflow that would be best, I'll give it a try and report back and try and use instrumentation during a video to produce real, measurable outcomes. I will be installing V-band flanges up and downstream of the muffler so I can install different mufflers to experiment. This venture will be subsidized by a local outfitter who wishes to be able to better tailor what its customers get. Meaning, they get a LOT of guys/gals coming through their doors every day asking for the same things as many of you, myself included, but don't want to shell out $1k+ for a catback system. So, we're going to try these theories out with about 4-5 different mufflers and record the results on video as well as with sound metering equipment for some unbiased results.

ever have any luck with this project??