Looking to swap out Muffler and get rid of baffle

JoshsSierra1500 · August 12, 2015

Hey all I am looking to get some better sound out of my 2015 GMC Sierra 1500. I have a few questions.

1. What size pipe is the factory inlet and outlet?

2. What is the muffler length? (I know I can get out there and measure it just thought someone knows)

3. With removing the Baffle does that cause any trouble codes?

4. Lastly I was debating on going with either MBRP or Flowmaster. The links are below. Any thoughts on which is better.

http://www.autoanything.com/exhausts-mufflers/65A6675A0A0.aspx

http://www.autoanything.com/exhausts-mufflers/65A3965A0A0.aspx

Thank you

Josh

Truckin 55 · August 12, 2015

Think pipe exhaust diameter is 3inch O.D , when ordering muffler or exhaust systems you enter what type of vehicle you have

There are numerous threads about exhaust systems and what are you calling a Baffle?

JoshsSierra1500 · August 13, 2015

Think pipe exhaust diameter is 3inch O.D , when ordering muffler or exhaust systems you enter what type of vehicle you have

There are numerous threads about exhaust systems and what are you calling a Baffle?

Yeah i was searching some of the other threads didnt see exactly what i needed and was trying to just start something up to see if anyone had any input.

On the baffle im talking about the Passive Exhaust Valve. My plan is to replace the stock muffler and get rid of that at the same time. So i was trying to see if I could get a longer muffler or if i would have to get a muffler and a section of pipe.

Josh

Truckin 55 · August 13, 2015

Yeah i was searching some of the other threads didnt see exactly what i needed and was trying to just start something up to see if anyone had any input.

On the baffle im talking about the Passive Exhaust Valve. My plan is to replace the stock muffler and get rid of that at the same time. So i was trying to see if I could get a longer muffler or if i would have to get a muffler and a section of pipe.

Josh

I guess you seen all the exhaust systems available, A reputable Muffler / custom exhaust shop will fix you right with a single or duel system. Large muffler mild to small loud and exhaust pipe is cut and bend to fit maybe within an hour or so. Some say of a buzz sound 4cyl mode but I don't or unable to hear it , I use M5 and switch to 6 on expressway . No codes should be thrown

JoshsSierra1500 · August 19, 2015

I guess you seen all the exhaust systems available, A reputable Muffler / custom exhaust shop will fix you right with a single or duel system. Large muffler mild to small loud and exhaust pipe is cut and bend to fit maybe within an hour or so. Some say of a buzz sound 4cyl mode but I don't or unable to hear it , I use M5 and switch to 6 on expressway . No codes should be thrown

Thank you so much for your very helpful response. I feel it warrants a very equal one.

robvas · August 20, 2015

1. What size pipe is the factory inlet and outlet?

2.75" on the 5.3 V8

2. What is the muffler length? (I know I can get out there and measure it just thought someone knows)

You want to get something with an overall length of 28-29" if you plan on removing the flapper valve.

The muffler itself is only 21" but you want to have some room to work with on both sides of the muffler as well as the flapper valve which is a few inches long itself.

3. With removing the Baffle does that cause any trouble codes?

Nope, it won't trigger a thing. Take it off!

4. Lastly I was debating on going with either MBRP or Flowmaster. The links are below. Any thoughts on which is better.

http://www.autoanything.com/exhausts-mufflers/65A6675A0A0.aspx

http://www.autoanything.com/exhausts-mufflers/65A3965A0A0.aspx

I wouldn't get either of those. I had a Flowmaster Super 44 on my last truck and when it went into V4 mode it sounded terrible. If you get a tune and disable AFM, or buy Range to disable AFM, it will sound find and you can go ahead and get a Flowmaster.

Also, the inlet on the stock muffler is offset so if you use a straight muffler like the MBRP you will have to have the shop bend some pipe to make it fit.

This Magnaflow (http://www.magnaflow.com/products?partNumber=12589) is the right fit except your muffler shop will have to match the 3" in/out with your 2.75" exhaust. Should be able to do that with a pipe expander, or they can bend you up a whole new 3" tailpipe but will cost you another $150 or so depending on the shop. It will sound find even if you leave AFM on.

Another good one to look at is the Dynomax SuperTurbo or Ultraflo.

The resonator is about a foot long just in case anyone wanted the measurements

Bvonscott · August 20, 2015

Keep in mind that the stock GM exhaust system on the 2014+ truck uses a muffler that has a straight through design. It is a huge heavy muffler with a ton of sound deadening material in it, but the flow from one side to the other is straight through. If you go with a flowmaster, keep in mind that it has baffles and not a straight through design like a magnaflow. When I had the flowmaster on my truck I was having a loss of power and it felt like it was dragging.

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JoshsSierra1500 · August 20, 2015

2.75" on the 5.3 V8

You want to get something with an overall length of 28-29" if you plan on removing the flapper valve.

The muffler itself is only 21" but you want to have some room to work with on both sides of the muffler as well as the flapper valve which is a few inches long itself.

Nope, it won't trigger a thing. Take it off!

I wouldn't get either of those. I had a Flowmaster Super 44 on my last truck and when it went into V4 mode it sounded terrible. If you get a tune and disable AFM, or buy Range to disable AFM, it will sound find and you can go ahead and get a Flowmaster.

Also, the inlet on the stock muffler is offset so if you use a straight muffler like the MBRP you will have to have the shop bend some pipe to make it fit.

This Magnaflow (http://www.magnaflow.com/products?partNumber=12589) is the right fit except your muffler shop will have to match the 3" in/out with your 2.75" exhaust. Should be able to do that with a pipe expander, or they can bend you up a whole new 3" tailpipe but will cost you another $150 or so depending on the shop. It will sound find even if you leave AFM on.

Another good one to look at is the Dynomax SuperTurbo or Ultraflo.

The resonator is about a foot long just in case anyone wanted the measurements

Dude super awesome response. Thank you soo much.

I think im going to go with that muffler you suggested. The shop said they can cut the muffler and the baffle out and weld the new muffler in place. My only other question is, is there any need to get rid of the resonator or no? If so should i just sack up and get a full single pipe bolt on kit?

I dont really want to spend a few hundred dollars right now and can get a muffler and have it put in super cheap but if its going to sound like crap with the resonator still there i can just wait a little till i have the funds and buy a full bolt on kit and my friend can help me install it.

Now jut not sure what to do

JoshsSierra1500 · August 21, 2015

Keep in mind that the stock GM exhaust system on the 2014+ truck uses a muffler that has a straight through design. It is a huge heavy muffler with a ton of sound deadening material in it, but the flow from one side to the other is straight through. If you go with a flowmaster, keep in mind that it has baffles and not a straight through design like a magnaflow. When I had the flowmaster on my truck I was having a loss of power and it felt like it was dragging.

Sent from my iPhone using Tapatalk

Hey man thank you for the heads up I hope that i dont notice any loss. If so ill just have to tune it

2.75" on the 5.3 V8

You want to get something with an overall length of 28-29" if you plan on removing the flapper valve.

The muffler itself is only 21" but you want to have some room to work with on both sides of the muffler as well as the flapper valve which is a few inches long itself.

Nope, it won't trigger a thing. Take it off!

I wouldn't get either of those. I had a Flowmaster Super 44 on my last truck and when it went into V4 mode it sounded terrible. If you get a tune and disable AFM, or buy Range to disable AFM, it will sound find and you can go ahead and get a Flowmaster.

Also, the inlet on the stock muffler is offset so if you use a straight muffler like the MBRP you will have to have the shop bend some pipe to make it fit.

This Magnaflow (http://www.magnaflow.com/products?partNumber=12589) is the right fit except your muffler shop will have to match the 3" in/out with your 2.75" exhaust. Should be able to do that with a pipe expander, or they can bend you up a whole new 3" tailpipe but will cost you another $150 or so depending on the shop. It will sound find even if you leave AFM on.

Another good one to look at is the Dynomax SuperTurbo or Ultraflo.

The resonator is about a foot long just in case anyone wanted the measurements

Again thank you for you input i Am going to be getting the Magnaflow muffler and having the pipes replaced from the muffler back.

Thank you

Josh

eatnupbyatornadr · August 21, 2015

Hey man thank you for the heads up I hope that i dont notice any loss. If so ill just have to tune it

Again thank you for you input i Am going to be getting the Magnaflow muffler and having the pipes replaced from the muffler back.

Thank you

Josh

you will not notice a loss with the 18" magnaflow and 3" pipe from the catalytic convertor on back. http://www.magnaflow.com/products?partNumber=11259 I just put that on my truck and i am happy. There is a tiny bit of chop in V4... but nothing major with the windows up and the radio off; turn the radio on and that chop disappears. I coupled it with an AFE Magnum FORCE Pro DRY S Stage-2 to make it sound meaner than it really is

txmuder · August 25, 2015

I also just replaced my exhaust with 18" Magnaflow 3" in 2 x 2.5" out, removed resonator of course, and the baffle assembly section. I am running a CAI & programmer with option of removing AFM but have not as of yet. I don't notice a big sound issue when in V4 mode and am enjoying the MPG increase from my last truck (2012 CC Silverado w/6.2).

The sound is a good strong deep sound and not as loud as my last setup which was a true duel system also with magnaflows.

Sierra Jon · December 11, 2015

this thread is only 10 replies long and 100 times more helpful than the others... just sayin.

Thanks all!

jrob56 · December 11, 2015

Ill be doing something similar but going with Borla and leaving flapper.. Never heard a truck on this forum sound as good as this one.

http://www.gm-trucks.com/forums/topic/179280-updated-exhaust-vids/

Sierra Jon · December 11, 2015

Ill be doing something similar but going with Borla and leaving flapper.. Never heard a truck on this forum sound as good as this one.

http://www.gm-trucks.com/forums/topic/179280-updated-exhaust-vids/

Yeah I'm going to do the Borla Pro XS #40359 swap but leave the valve and the resonator in at first to see how I like it... I do a decent amount of towing in the summer so the valve is likely going to stay either way and I'll clamp it open when I'm not towing.