MagnaFlow 15267 Performance Cat-Back Exhaust System

[bhardy]

Hey everyone,

I'm looking into getting a exhaust system and have heard good things about the MagnaFlow 15267 Performance Cat-Back Exhaust System. Is anyone running there system on there 2014 an up Silverado 1500? Is there any bad drone when kicked into V4 mode? I'm wanting just a nice deep rumble and an exhaust that you can tell its a V8 when punched on. Does this exhaust do this?

Thanks guys.

[2018GMC]

Hey everyone,
I'm looking into getting a exhaust system and have heard good things about the MagnaFlow 15267 Performance Cat-Back Exhaust System. Is anyone running there system on there 2014 an up Silverado 1500? Is there any bad drone when kicked into V4 mode? I'm wanting just a nice deep rumble and an exhaust that you can tell its a V8 when punched on. Does this exhaust do this?
Thanks guys.

I just did a magnaflow 12909 / 14909 stainless muffler only. Had the shop chop out my stock muffler and flapper. Weld in 22” long magnaflow. Kept the stock resonator.

Still very quiet at highway cruse. No drone in v4 or highway speeds. You can hear the cold starts now and above 3k rpm sounds like a v8. I have 6.2 with 3.5” diameter pipe. 5.3 has slightly smaller diameter I believe.

I’m glad I didn’t go louder especially when towing. Now I can hear some v8 rumble. Its definitely tame but a cheaper option than a cat back. Muffler is $120 for aluminized and $180 for stainless. Depending on shops in your area $30 - $100 to cut stock muffler out and weld new in.

[2018GMC]

See photos below

[2018GMC]

[SSchup]

I have the Magnaflow 15239 on my 2018 6.2 Silverado. I love the sound. nice deep rumble at start up and very quiet at cruising speeds. Can definitely here it when you put your foot into it. I've not noticed any drone what so ever and I have AFM still active. I couldn't stand how quiet the stock exhaust was, couldn't even hear it when I remote started it. 

 

Only thing I may change is the 5" tip, just not sure I care for the size. I'm taking it to my exhaust guy to see if we can change the tip to something a little less noticeable. 

[bhardy]

14 minutes ago, 2009GMC said:

 

I just did a magnaflow 12909 / 14909 stainless muffler only. Had the shop chop out my stock muffler and flapper. Weld in 22” long magnaflow. Kept the stock resonator.

Still very quiet at highway cruse. No drone in v4 or highway speeds. You can hear the cold starts now and above 3k rpm sounds like a v8. I have 6.2 with 3.5” diameter pipe. 5.3 has slightly smaller diameter I believe.

I’m glad I didn’t go louder especially when towing. Now I can hear some v8 rumble. Its definitely tame but a cheaper option than a cat back. Muffler is $120 for aluminized and $180 for stainless. Depending on shops in your area $30 - $100 to cut stock muffler out and weld new in.

 

Did the shop literally just chop off the stock muffler/valve and weld in the new magnaflow muffler you got? They didnt have to bend any new pipe for it to match up with the new muffler did they? Also, if i were to just leave the flapper valve on and just chop off the muffler would it change anything?

[2018GMC]

Did the shop literally just chop off the stock muffler/valve and weld in the new magnaflow muffler you got? They didnt have to bend any new pipe for it to match up with the new muffler did they? Also, if i were to just leave the flapper valve on and just chop off the muffler would it change anything?

Yes on first question. Measure twice, cut once and no additional pipe needed. There is a magnaflow 12909 thread in the exhaust mods section with more info. Some have left flapper and added muffler. Sounds near stock until you floor it. Even with the flapper open it is a restriction in the system. They can also squeak over time.

Some have had just a pipe welded in place of stock muffler. But you may get drone or helicopter chop noise in v4.

I noticed the exhaust tone in v4 with stock system. It isn’t much different now. The biggest change is cold starts and more v8 rumble exhaust tone above 3k rpm.

[bhardy]

27 minutes ago, 2009GMC said:

 

Yes on first question. Measure twice, cut once and no additional pipe needed. There is a magnaflow 12909 thread in the exhaust mods section with more info. Some have left flapper and added muffler. Sounds near stock until you floor it. Even with the flapper open it is a restriction in the system. They can also squeak over time.

Some have had just a pipe welded in place of stock muffler. But you may get drone or helicopter chop noise in v4.

I noticed the exhaust tone in v4 with stock system. It isn’t much different now. The biggest change is cold starts and more v8 rumble exhaust tone above 3k rpm.

 

Awesome thanks for the info man. Was the reason you didn’t go with a full system just because of the cost? Just curious

[bhardy]

43 minutes ago, SSchup said:

I have the Magnaflow 15239 on my 2018 6.2 Silverado. I love the sound. nice deep rumble at start up and very quiet at cruising speeds. Can definitely here it when you put your foot into it. I've not noticed any drone what so ever and I have AFM still active. I couldn't stand how quiet the stock exhaust was, couldn't even hear it when I remote started it. 

 

Only thing I may change is the 5" tip, just not sure I care for the size. I'm taking it to my exhaust guy to see if we can change the tip to something a little less noticeable. 

I’m guessing that’s the same system but for the 6.2L?

Would you say it’s worth it to go with a full exhaust system than just a muffler swap?

[2018GMC]

17 minutes ago, bhardy said:

I’m guessing that’s the same system but for the 6.2L?

Would you say it’s worth it to go with a full exhaust system than just a muffler swap?

For the price, can’t beat a muffler swap. I wanted a corsa catback but costs $1200. All the catbacks are for sound only. No advertised hp and tq gain. 

 

I was looking for better flow and more sound. The muffler swap and flapper delete was a steal compared to a catback. 

 

If money was no object and I was going to tune, I would go catback for sure

[Hate Work]

OP: I have the 12588, which is a 22" catback. The sound is wonderful but is more quiet than the 18" you are looking at. I bought the muffler through Amazon and had my local shop put it on. Muffler, tips, their piping..... Less than $400. One of the best mods I have done.

[bhardy]

10 minutes ago, Hate Work said:

OP: I have the 12588, which is a 22" catback. The sound is wonderful but is more quiet than the 18" you are looking at. I bought the muffler through Amazon and had my local shop put it on. Muffler, tips, their piping..... Less than $400. One of the best mods I have done.

So all you did was a muffler swap as well? Cut the old one out weld the new one in and new piping after that? 

[bhardy]

20 minutes ago, 2009GMC said:

For the price, can’t beat a muffler swap. I wanted a corsa catback but costs $1200. All the catbacks are for sound only. No advertised hp and tq gain. 

 

I was looking for better flow and more sound. The muffler swap and flapper delete was a steal compared to a catback. 

 

If money was no object and I was going to tune, I would go catback for sure

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

[Hate Work]

32 minutes ago, bhardy said:

So all you did was a muffler swap as well? Cut the old one out weld the new one in and new piping after that? 

No. Went to catback duals. Straight back. I'm on my phone but think there is a pic in my profile.

[J_Mas6.2]

I went with the Borla 40946 XR-1 muffler. removed the flapper valve.  Has a nice deep rumble at startup and city driving.  Can't tell its on there on the highway unless you are passing someone.