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Best performing exhaust with quite sound


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What do you guys think about me trying to get the "flappers" and having an exhaust shop install them? I hear that's where all the annoying sound come from, removing them...I cant see them on GMPARTSDIRECT.com so I wonder if I can buy just the flappers..??

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On 12/29/2019 at 6:17 PM, OnTheReel said:

The resonators help reduce drone. The adaptive valves (flappers) are the thing that cut the helicopter sound down. Unfortunately they also cut the power the most; very restrictive, even wide open. Look at a cross section of them once.

 

Frankly you can’t have it both ways. A well designed cat-back mitigates some of the unsavory noises, all of the drone and adds a fair bit of power (13hp on the 6.2 for the GMPP setup). But that setup is still louder and still has some odd noises in DFM. I live with it because the sound at WOT is just sublime.

Does the GM performance Cat Back maintain the adaptive valve? Where is it located?

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6 minutes ago, JacobC1983 said:

So when the Borla went in did they cutout the adaptive valve or was there not one on our trucks 

In the stock exhaust there are adaptive valves right before, and right after the muffler on 6.2 trucks (5.3 trucks only have one). Since the GM performance exhaust replaces everything behind the cat, all that stuff is done away with in the process.

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I have a custom, has a 5.3 with afm. I have a range afm disabler. Keeps the truck in v8 mode all the time.  My truck only has 2500 miles on it. 900 miles ago I put the gibson on and its rusty brown already. If i look in the wheel well u see the brown pipe which sucks.


Same here. The first salt and they rusted. Not happy. Gibson said steel wool would take it off. Guess it will be a spring project. Just thought it would last a bit before rusting.


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OEM is 409 too, but at least they aluminize it so it doesn’t look like garbage after some time in the salt. Doesn’t sound like the Gibson does anything to theirs. But as always and with anything...you get what you pay for in the aftermarket. Borla is 304. GMPP is 304.

 

Rust isn’t going to hurt it any time soon. But I’d probably not be happy putting on something lower grade than the even the elcheapo stock part.

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25 minutes ago, OnTheReel said:

In the stock exhaust there are adaptive valves right before, and right after the muffler on 6.2 trucks (5.3 trucks only have one). Since the GM performance exhaust replaces everything behind the cat, all that stuff is done away with in the process.

I’m thinking I wish the GM performance exhaust was a little quieter on the highway.  It’s not bad but it does have some drone. Is there something easy that can be done.

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1 minute ago, JacobC1983 said:

I’m thinking I wish the GM performance exhaust was a little quieter on the highway.  It’s not bad but it does have some drone. Is there something easy that can be done.

Think a couple people here have added resonators back in the stock locations before the taillpipes. They tame it down a bit without adding much, if any restriction.

 

Haven’t noticed any drone on mine, but it is a bit louder than some people would expect from a “factory part”. Still the quietest catback I’ve heard in person.

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I did a full tru dual on mine split the Ypipe into 2 and went into a 22" magnaflow dual 2 1/2" in and dual 2 1/2" out on mine, I have a 6.2. I was surprised at how quiet it is. I was just looking for a lil better performance and didn't want much noise if any at all. I have ZERO drone at any speed and I really can't even hear when DFM kicks in. The stock exhaust is very restrictive, the flapper before and after the stock muffler cover about 40% of the pipe when fully open not to mention how long it takes before it fully opens when you mash on the accelerator. 

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Edited by Luis Marroquin
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I have to ask the obvious... If you want it quiet, why install an exhaust at all?  Leave it stock.

Unless you couple a catback exhaust with a CAI and preferably a tune, you really are not gaining any performance...  

The intake and exhaust either needs to be less restrictive to make a little more power, or it can be quiet...  It's kinda hard to pick up any significant power and also have it stay quiet.  It's one or the other, and you need to pick ONE and call it a day, IMHO.

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