MagnaFlow 15267 Performance Cat-Back Exhaust System

[J-man67]

I'm on the cut out and replace muffler team. Save the money for a tune or maintenance. You'll achieve the same thing. My 15 is stock but did this on my 07. 5.3 uses 3"pipe. I got a corsa muffler at 2.5 in/out. I know most will disagree, by reducing the diameter I kept similar back pressure as aftermarket mufflers are more free flowing. Sounded great, and saw slight improvement on mpg. Wasn't going for that (had 8" lift and 35s)buuuut it was noticed.

My 15 has 160k on the clock so might not do much to this truck as it's a work beast mostly, but local shop told me 250 for magna flow installed. Might just do it!

Either way, you'll get your truck to sound like it actually has a v8 in it. I also ALWAYS drive in manual mode in 5th (6spd trans) and keep it out of final gear and it doesn't go into v4 mode. Any drone problems solved!

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[bhardy]

2 hours ago, J-man67 said:

I'm on the cut out and replace muffler team. Save the money for a tune or maintenance. You'll achieve the same thing. My 15 is stock but did this on my 07. 5.3 uses 3"pipe. I got a corsa muffler at 2.5 in/out. I know most will disagree, by reducing the diameter I kept similar back pressure as aftermarket mufflers are more free flowing. Sounded great, and saw slight improvement on mpg. Wasn't going for that (had 8" lift and 35s)buuuut it was noticed.

My 15 has 160k on the clock so might not do much to this truck as it's a work beast mostly, but local shop told me 250 for magna flow installed. Might just do it!

Either way, you'll get your truck to sound like it actually has a v8 in it. I also ALWAYS drive in manual mode in 5th (6spd trans) and keep it out of final gear and it doesn't go into v4 mode. Any drone problems solved!

Sent from my SM-N950U using Tapatalk
 

Strongly considering just a muffler swap. Do you know what magnaflow muffler you are going to be getting for your 15? Also, did you only take the muffler out and swap it or did you take out the resonator and flapper valve as well?

[J-man67]

Strongly considering just a muffler swap. Do you know what magnaflow muffler you are going to be getting for your 15? Also, did you only take the muffler out and swap it or did you take out the resonator and flapper valve as well?

I don't know which one yet. Used Corsa black series last time and had an amazing sound. Think they were discontinuing them back then though. Your local muffler shop will know exactly what to use as far as inlet/outlet offsets and such. I actually just got another quote as I was picking up one of my work trucks from a shop. They said 240. I'm in Delaware, but should be similar. Might even find it cheaper in your neck of the woods but honestly if you don't plan on full headers and other engine mods, a simple muffler swap is your answer!

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[bhardy]

Has anyone tried the Flowmaster 40 series muffler with the resonator and flapper still on?

[J-man67]

I always heard and felt the Flow Masters to be a little too loud/aggressive compared to MagnaFlow. To each there own

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[captaincool]

On 2018/11/29 at 8:45 AM, bhardy said:

Understood. I may have to put that into consideration. May just save up the cash for the full system.

I think a long tube header and a muffler will be enough for you, or an exhaust tip to make your truck perfect. 

[jaxcam02]

Well since this post has been brought back from a 4 month hiatus, for those interested in the OP's question about the 15267 exhaust.

 

After install and driving it at first, the flapper valve would cause a whistling sound, as a result I clamped the valve open.

However, on the highway there is a moderate drone now between 1600 and 2000 RPMs which is right where my truck wants to hover at highway speeds. 

I am going to unclamp the flapper and just see whether the drone remains or not. Eventually I'm cutting the flapper off since I have the v4 blocked but I have to find something for the drone, hopefully a small resonator in its place will do the trick.

[Gagliano7]

I have the flowmaster catback for my 2018 6.2 dual out the back. There is no drone and the sound is great but not to loud. I tried replacing the muffler with a super 44 but the sound was better with the one that cam with the catback the 50 Series HD Muffler. 

[captaincool]

On 2019/3/8 at 8:27 PM, jaxcam02 said:

Well since this post has been brought back from a 4 month hiatus, for those interested in the OP's question about the 15267 exhaust.

 

After install and driving it at first, the flapper valve would cause a whistling sound, as a result I clamped the valve open.

However, on the highway there is a moderate drone now between 1600 and 2000 RPMs which is right where my truck wants to hover at highway speeds. 

I am going to unclamp the flapper and just see whether the drone remains or not. Eventually I'm cutting the flapper off since I have the v4 blocked but I have to find something for the drone, hopefully a small resonator in its place will do the trick.

I agree with you, the resonator will help to solve the drone problem. 

[jaxcam02]

3 hours ago, captaincool said:

I agree with you, the resonator will help to solve the drone problem. 

Any recommendations on a resonator for 3 inch piping?

[captaincool]

1 hour ago, jaxcam02 said:

Any recommendations on a resonator for 3 inch piping?

lots of options out there on Ebay, maybe just try the 13" long resonator, it might be help

[jaxcam02]

So I unclamped my flapper valve just to see if the drone was effected. Sure enough the drone went away with the valve unclamped but the whistling noise was back. I just gotta cut that thing out of there and remove that from the equation.

[Pat Teke]

I just put this system in my ‘15 5.3

has horrific drone and helicopter 1200-1800 rpm.

 

left flapper alone.

 

what resonator did you go with? And in what location

 

factory after the axle or mid pipe before the muffler?