Anyone with GM Performance Cat-Back Exhaust/Air Intake ?

[OnTheReel]

5 minutes ago, Schmoe said:

So, interestingly, I took the truck in today fornits first oil change (came with purchase of truck). I showed them thread, and magically they are willing to match all these prices now.  But the sale guy did ask me if I would just pay $100 more than what was show , with a straight face. I asked him why I would do that, and he just said “I’m a sales guy. I have to try”. Ughhhh...

I guess it’s good they came around, but still kind of shady.

 

I’m still on the fence as far as the intake. I am very happy with the exhaust alone and part of me doesn’t really want any more noise, especially if there isn’t hardly any performance benefit. I had the Airraid MIT on my 2016 and the intake sounds were pretty annoying at anything but WOT. Especially during cylinder deactivation.

[BLACK AT4]

On 3/13/2019 at 9:12 AM, Scooter Scott said:

On my 2018 I just swapped out my muffler with a Magnaflow 12909 and removed the flapper and the sound was great.  Don't get me wrong, the offroad exhaust the GM offers sounds badass...but is it $1300 badass over a $100 muffler?

Did you remove the flapper on the inlet and outlet or just the inlet? I just ordered the Magnaflow 12909 and will have it installed next week

[OnTheReel]

48 minutes ago, BLACK AT4 said:

Did you remove the flapper on the inlet and outlet or just the inlet? I just ordered the Magnaflow 12909 and will have it installed next week

If I remember right K2s only have one. Simple muffler swaps aren’t as easy or beneficial on these. Mega long muffler, two valves, two resonators. By the time you’re done getting rid of everything to get the right sound, over half of the cat-back piping has been replaced anyway, there’s a bunch of new seams to leak, and the $1300 seems like a bargain over the pain-in-the-ass alternative. Just my 2 cents of course...

[Scooter Scott]

Did you remove the flapper on the inlet and outlet or just the inlet? I just ordered the Magnaflow 12909 and will have it installed next week

On the 2018 there was only one flapper right after the muffler I thought.


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[BLACK AT4]

On the 2019 there is a flapper before and after.there is also 2 resonators .. I'm wondering what I need to remove? Resonators and flappers, or just flappers? I guess I will try it with the resonators and then without if I don't like the sound . 

[KARNUT]

On the 2019 there is a flapper before and after.there is also 2 resonators .. I'm wondering what I need to remove? Resonators and flappers, or just flappers? I guess I will try it with the resonators and then without if I don't like the sound . 

I would start with just the muffler. I would imagine the two flappers have to do with the split fire cylinder deactivation. On my 14 I left the flapper and change the muffler. Later I tuned out the cylinder deactivation, I don’t think you can tune the 19s yet.


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[BLACK AT4]

2 hours ago, KARNUT said:

I would start with just the muffler. I would imagine the two flappers have to do with the split fire cylinder deactivation. On my 14 I left the flapper and change the muffler. Later I tuned out the cylinder deactivation, I don’t think you can tune the 19s yet.


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I dont believe the cat back system has the flappers which would lead me to believe it has nothing to do with cylinder deactivation, rather they are used to meet certain noise levels as these are spring loaded valves that appear to open as you press the accelerator. 

[KARNUT]

I dont believe the cat back system has the flappers which would lead me to believe it has nothing to do with cylinder deactivation, rather they are used to meet certain noise levels as these are spring loaded valves that appear to open as you press the accelerator. 

No they baffle the helicopter sound when you drop out of V8. Have two on the 19 tells me that when it drops below 4 cylinders they help deaden that sound.

 

 

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[Scooter Scott]

24 minutes ago, BLACK AT4 said:

I dont believe the cat back system has the flappers which would lead me to believe it has nothing to do with cylinder deactivation, rather they are used to meet certain noise levels as these are spring loaded valves that appear to open as you press the accelerator. 

I think you are right that the flappers aren't on the cat back system

[KARNUT]

I think you are right that the flappers aren't on the cat back system

I’ve read on this site that the GM performance cat back had the flapper. I haven’t had performance exhaust at my bender in awhile, I suspect they will or have started addressing the cylinder deactivation changes in the muffler it self, with baffling and chambers. Seems logical. I’ll have to pay my exhaust bender a visit and find out. I’ve been thinking about putting exhaust on my V6-4cylinder vehicles only if their stock quiet at cruise.


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[BLACK AT4]

1 hour ago, KARNUT said:

I’ve read on this site that the GM performance cat back had the flapper. I haven’t had performance exhaust at my bender in awhile, I suspect they will or have started addressing the cylinder deactivation changes in the muffler it self, with baffling and chambers. Seems logical. I’ll have to pay my exhaust bender a visit and find out. I’ve been thinking about putting exhaust on my V6-4cylinder vehicles only if their stock quiet at cruise.


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1 hour ago, Scooter Scott said:

I think you are right that the flappers aren't on the cat back system

https://accessories.gm.com/mychevrolet/product/2019/GMC/Sierra 1500/62l-short-wheel-base-cat-back-dual-exit-exhaust-system-upgrade-84527234?bac=221437

Here is a link to the GM Cat Back system with a pic showing the components. It appears there is no flapper. Also, the price ordered from this site is $1,595. The link below is the same part number, different GM Website price is $1,291.95. So if you do decide to buy a catback system buy from gmpartsonline. I'm going to try the Magnaflow 12909 and will post my results. 

https://www.gmpartsonline.net/oem-parts/gm-performance-exhaust-upgrade-84527234/?c=Zz1wZXJmb3JtYW5jZSZzPWV4aGF1c3QmYT1nbWMmbz1zaWVycmEtMTUwMCZ5PTIwMTkmdD1hdDQmZT02LTJsLXY4LWdhcw%3D%3D

[Scooter Scott]

Just now, BLACK AT4 said:

 

https://accessories.gm.com/mychevrolet/product/2019/GMC/Sierra 1500/62l-short-wheel-base-cat-back-dual-exit-exhaust-system-upgrade-84527234?bac=221437

Here is a link to the GM Cat Back system with a pic showing the components. It appears there is no flapper. Also, the price ordered from this site is $1,595. The link below is the same part number, different GM Website price is $1,291.95. So if you do decide to buy a catback system buy from gmpartsonline. I'm going to try the Magnaflow 12909 and will post my results. 

https://www.gmpartsonline.net/oem-parts/gm-performance-exhaust-upgrade-84527234/?c=Zz1wZXJmb3JtYW5jZSZzPWV4aGF1c3QmYT1nbWMmbz1zaWVycmEtMTUwMCZ5PTIwMTkmdD1hdDQmZT02LTJsLXY4LWdhcw%3D%3D

I'm interested in your results on the 12909

[Schmoe]

4 minutes ago, Scooter Scott said:

I'm interested in your results on the 12909

As am I. BlackAT4 what price have you found on the 12909?

[Scooter Scott]

Just now, Schmoe said:

As am I. BlackAT4 what price have you found on the 12909?

https://smile.amazon.com/MagnaFlow-Exhaust-Products-12909-Muffler/dp/B000XQM1LC/

 

$117 on amazon

[BLACK AT4]

3 hours ago, Schmoe said:

As am I. BlackAT4 what price have you found on the 12909?

I found the best deal on Amazon for $117.