Make a K2 '15 exhaust sound like a GMT 900 '07-'13 exhaust

[TaterGator]

Hey guys, I've tried searching everywhere and can't find an answer anywhere! I love the slightly off silent rumble that the GMT 900 trucks had. I am disappointed at how silent my 2015 Silverado is and would love to match the sound of the last gen Silverados. Any idea how to do it? I've heard 1 of the 3 cats is a resonator, so would deleting it do the trick? Or is it the actual muffler and I need to replace the muffler with a GMT 900 platform muffler? If I need to replace the muffler, do you guys know any aftermarktet equivalent to the sound of the stock 5.3 last gen mufflers. Thanks y'all!

[SouthernSilveradoGuy85]

So you want it to sound like a stock GMT900? The K2s have a 3rd cat AND a resonator. The resonator is behind the muffler and you could try to remove it and see how it is. I went from stock to a Flowmaster Super 44 dual out muffler so I didn't mess with different ways. Just had them remove the muffler and everything behind it and kept the 3rd cat and my truck is very loud. I don't think removing the 3rd cat will do anything to noise. Or you could replace the muffler with a stock muffler from a 900. It probably won't sound exactly the same since the gas engines in the 1/2 ton K2s are all new redesigned engines.

[Silverado-Hareek]

I want to do this exact same thing to my truck! I believe we need to delete both the flapper valve behind the muffler and the resonator which is the big thing near the end of the tailpipe by the spare tire. I believe the muffler can stay. I'm not sure about the 3rd cat if that's muting the exhaust or not but it is not a monitored cat so removing it won't throw any codes or anything.

[07Softail]

Removing 3rd cat does nothing for sound.

 

RT

[TaterGator]

I want to do this exact same thing to my truck! I believe we need to delete both the flapper valve behind the muffler and the resonator which is the big thing near the end of the tailpipe by the spare tire. I believe the muffler can stay. I'm not sure about the 3rd cat if that's muting the exhaust or not but it is not a monitored cat so removing it won't throw any codes or anything.

That's what I was hoping to hear! I've read all about that flapper causing problems and squeeking so many end up removing them entirely. I can't find a concise answer at what its function is in V4 mode to even know if there would be any problems removing it. Would reduced back pressure mean it looses a noticeable amount of low end torque in V4 mode? Any warranty voiding implications? I read that a resonator works more as a bandpass filter that cancels noise at a short frequency (I'm guessing 1800 rpm range). Wonder if removing either would cause a significant drone.

 

I wish I could hear a youtube comparison of the 2, but for now I think Ill try temporary clamping the flapper open and seeing how it goes...hate to do any surgery on a 4 day old truck!

[TaterGator]

Found a few answers on this post about the flapper...

 

http://www.gm-trucks.com/forums/topic/158614-free-exhaust-mod/

 

Hell with it, I'm gonna get a hose clamp and try it out when I get some free time!

[Silverado-Hareek]

Found a few answers on this post about the flapper...

 

http://www.gm-trucks.com/forums/topic/158614-free-exhaust-mod/

 

Hell with it, I'm gonna get a hose clamp and try it out when I get some free time!

 

Read around some more there's another method using a bolt and a nut to hold the flapper valve open. The hose clamp can (may not but can) work it'self loose over time. The bolt permanently holds the flapper valve open. Also the flapper valve is only there to help reduce the V4 drone. Removing it won't harm anything.

 

I'm getting really close to pulling the trigger on a Range AFM delete module to eliminate V4 all together. I don't know what GM is talking about but I feel the switch to V4 in this truck MORE than on my GMT900 and there's a noticeable hesitation and loss in power when it switches to V4 and when it switches out of it. Driving around in M5 is like driving a completely different truck as it's locked in V8 when in M5. I'd rather lose some MPG's and have V8 power full time and an overall more pleasurable driving experience than to keep the AFM functional. Hopefully over the course of the next year I plan to:

 

1) Buy and install Range AFM Delete module

2) Remove resonator on the exhaust

3) Remove the flapper valve on the exhaust

 

Hopefully that gives me that old GM throaty exhaust note that used to come stock on their trucks and SUV's and enhances the driving experience with V8 power full time while eliminating any V4 drone.

[Luster]

I had a '13 Silverado. I had my exhaust shop put on a 18" Magnaflow. Sounded like a muscle car. Loved it from day one!

 

Traded for a new '14 Silverado. Exhaust guy put on a 22" Magnaflow. No difference in sound from stock.

 

I had him put on a 14" Magnaflow and delete the flapper and resonator. I like the exhaust sound a lot.

 

But honestly, the '13 truck sounded better. Deeper and louder.

[RyanbabZ71]

Stock my 2010 6.2 Silverado had a nicer exhaust sound than my 2012 L99 camaro. This has been taken car of now I want my truck to sound meaner

 

 

Ryan

[Luster]

Stock my 2010 6.2 Silverado had a nicer exhaust sound than my 2012 L99 camaro. This has been taken car of now I want my truck to sound meaner

 

 

Ryan

 

[RyanbabZ71]

No shorties come on haha

 

 

Ryan