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Seriously- borla muffler/other mods versus entire cat back


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So I have read every post I can find, and I have seen a few times mentioned that simply placing a borla muffer(xs type) will lead to drone. 

 

What I can’t understand is why that would be. What other modifications or differences does the full borla cat back offer? Assumption of a new muffler and any other mods-resonator flapper etc.

 

believe me, I’ll spend the money on the full system if need be, but I can’t really understand the true difference( between having all stainless).

 

Can anyone explain in any kind of detail as to why it’s worth or not worth spending the extra 1,000??

 

thanks 

Edited by RPaul
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There's a lot of science and R&D that goes into developing a good exhaust system that doesn't drone but still works efficiently.  For example, certain harmonics have to be tuned out throughout the whole RPM range.  I just test drove a '20 RST that someone had taken to a local exhaust shop and had what looked like a flowmaster installed where the muffler went and also had the resonators cut off in the back.  I only had to drive a few blocks to know that truck wasn't for me.  Quite annoying in the cab.  And even worse when cylinders started shutting down.

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Understand and agree with that completely. My question is specifically what differentiates the borla cat back system versus purchasing a borla muffler and cutting out flappers after the muffler.

 

to be even more specific , the borla catback seems to be a muffler and then straight pipe back to tips. Granted (maybe) borla bent them to change some sound but does the way the pipes route to tips change that much?

 

again I’m being open minded, but it’s a pretty legitimate question. 
 

im looking at an image of the cat back system and all I can see is a muffler and then a pipe split straight to tips. What am I missing?

 

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52 minutes ago, RPaul said:

Understand and agree with that completely. My question is specifically what differentiates the borla cat back system versus purchasing a borla muffler and cutting out flappers after the muffler.

 

to be even more specific , the borla catback seems to be a muffler and then straight pipe back to tips. Granted (maybe) borla bent them to change some sound but does the way the pipes route to tips change that much?

 

again I’m being open minded, but it’s a pretty legitimate question. 
 

im looking at an image of the cat back system and all I can see is a muffler and then a pipe split straight to tips. What am I missing?

 

I often wondered this myself.  I swaped my stock muffler out for a straight through vibrant quiet muffler and it had a deep mellow tone, but droned like crazy! Why doesn't the Borla? I even left the factory resonators on my 6.2 in place. Mind you I called Borla and tried to buy just their touring muffler that they sell with their full exhaust. They wouldn't do it. So I found a new in the box GM pp exhaust "which is the same as the Borla touring system" for 700 on marketplace. When I got it I looked in the muffler and although it's a straight through design. It has a hole on the one side of the core. That is where the difference is. Not the tubing design. It's in the muffler and let me tell you it works! 

The only other muffler I thought of trying was this one from Banks.

https://www.bankspower.com/i-955-exhaust-muffler-stainless-steel-3-5-inch-inlet-and-outlet-for-2005-2016-ford-truck-6-8l-6-2l-and-chevy-6-0l-6-2l.html It has an expansion chamber that claims to eliminate drone.

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3 hours ago, RPaul said:

Thanks for reply, so you installed only the muffler or the entire performance exhaust?

For the GM performance exhaust on my 2020 LT 5.3L (side exit vs dual rear exit) the exhaust tubing is larger than stock (3" vs 2.75"), therefore increasing flow.  Even though the side exit performance exhaust is not made by Borla, I believe the dual rear exit exhaust made by Borla also has the larger diameter tubing as well, so that's a benefit of the entire CAT-back system over just replacing the muffler.

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1 hour ago, Anacortes Army Guy said:

For the GM performance exhaust on my 2020 LT 5.3L (side exit vs dual rear exit) the exhaust tubing is larger than stock (3" vs 2.75"), therefore increasing flow.  Even though the side exit performance exhaust is not made by Borla, I believe the dual rear exit exhaust made by Borla also has the larger diameter tubing as well, so that's a benefit of the entire CAT-back system over just replacing the muffler.

Exactly.  The stock 6.2 exhaust starts at 3.5" and necks down to 3" at the muffler and flapper and then back to 3.5" before it splits into 2 2.5" dual pipes. When I cut the muffler out I replaced it with a 3.5" muffler and bought a length of 3.5" 304ss tubing to eliminate all the 3" tubing.

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I didn't want to do a cat-back system so at first, I put a Flowmaster FlowFx on my truck.  Sounded great most of the time but the drone was terrible.  DFM was really noticeable as well.  I decided to try the Flowmaster Super 50 part#53055.  It sounds perfect now.  Definitely louder than stock but completely tolerable at highway speeds.  No drone.

 

I left my resonators on but had the flapper removed.  Very happy with it now.

 

https://www.summitracing.com/parts/flo-53055?seid=srese1&gclid=CjwKCAjw3_KIBhA2EiwAaAAliuyrX8RlH5bSJ0VvQZe8MqCOCJaZbqF_F7h5F7qdj_sygqHqls_8ABoC3YYQAvD_BwE

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Just replace the muffler with a piece of pipe.  Leave the flapper(s) in place.  I did it on my 5.3l and don't have any drone.  No louder than the Goodyear tires that the Trail Boss come with.

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On 8/17/2021 at 10:05 PM, Firehawk99 said:

I often wondered this myself.  I swaped my stock muffler out for a straight through vibrant quiet muffler and it had a deep mellow tone, but droned like crazy! Why doesn't the Borla? I even left the factory resonators on my 6.2 in place. Mind you I called Borla and tried to buy just their touring muffler that they sell with their full exhaust. They wouldn't do it. So I found a new in the box GM pp exhaust "which is the same as the Borla touring system" for 700 on marketplace. When I got it I looked in the muffler and although it's a straight through design. It has a hole on the one side of the core. That is where the difference is. Not the tubing design. It's in the muffler and let me tell you it works! 

The only other muffler I thought of trying was this one from Banks.

https://www.bankspower.com/i-955-exhaust-muffler-stainless-steel-3-5-inch-inlet-and-outlet-for-2005-2016-ford-truck-6-8l-6-2l-and-chevy-6-0l-6-2l.html It has an expansion chamber that claims to eliminate drone.

 

same design as corsa. I had 2 borla pro xs in line, still couldn't endure the drone while towing. purchased corsa sport on marketplace and left borla's with muffler shop.

 

 

 

Edited by e.texerado
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I am sure it is due to the size in the muffler. I had an atak muffler welded in and initially not horrible but after about 500 miles it droned so bad on the 6.2 that it gave my 8 yo car sickness . Went with the Corsa sport and will not look back. No drone AT ALL.  Unfortunately it is in the shop with 4700 and I think it has the dreaded valve issue. Happened on the interstate 600 miles from home, but that's a post for a different forum

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10 hours ago, e.texerado said:

 

same design as corsa. I had 2 borla pro xs in line, still couldn't endure the drone while towing. purchased corsa sport on marketplace and left borla's with muffler shop.

 

 

 

Great video. There's proof you get what you pay for!

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