New exhaust, no drone, no chopper, flapper relocate

[07Softail]

Dude get rid of the flapper valve, it is nothing more than a huge airflow restriction in the system. I have the 6.2 so I am running the Magnaflow 12909 muffler, no flapper and no resonator and have absolutely no drone. I get a very faint chopper sound under V4, but you have to really listen for it to hear it.

Do you have headers?

 

RT

[Badass69]

The flapper is kill noise..... it has nothing to do with with exhaust size or otherwise as TJ said..... When in V4 you have a V8 that still has 4 dead holes operating with no spark and fuel and minimal air movement but still some....and it sounds like crap lol. The valve tries to even the pulses out a bit by being a restriction and thus flow condition the exhaust gases to get less of a chopping sound. Dealers here were clamping open the valves on the 2014's when they came out as they were freezing closed..... it does nothing to performance per say when in V4 with it open....

 

AFM isn't new... every 5.3 half ton since 2007 has had it and they didn't have these goofy butterfly valves in the exhaust lol.

[redhot1.4]

There's no way in hell it loses back pressure. Just because it's in V4 mode , don't mean 4 other pistons stop moving

[Badass69]

There's no way in hell it loses back pressure. Just because it's in V4 mode , don't mean 4 other pistons stop moving

Backpressure is good for a generator I work with making water into steam... has dick all to do with an engine and making power.... You want to keep the velocity as high as possible with as little measurable restriction as possible.

 

The valve is flow conditioning so it's doesn't sound like a helicopter as much...

 

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[AZ_SS]

There's no way in hell it loses back pressure. Just because it's in V4 mode , don't mean 4 other pistons stop moving

In V4 mode the lifters colapse not allowing the valves to open, this does not allow those cylinders to pump.

[Bsass220]

On 3/30/2016 at 12:30 PM, Justin Nachazel said:

 

This is correct.

Here is why we have an adaptive valve. During normal operation in v8 mode the vehicle has the correct size piping for the resulting exhaust. When the truck switches into v4, there is a different amount of air moving through pipes that are too big. A good example is to look at a v4 vehicle exhaust system vs a v8, the pipes are smaller to accommodate the appropriate movement of air. The purpose of the adaptive valve is to essentially compensate for this. When in v8 mode there is enough air to push the valve open and allow full pipe. When the pressure drops, the valve closes slightly simulating a smaller pipe. I thought by moving the valve It would compensate till while allowing for the muffler to give me more sound. ProModMike and I will be trying a work around by simulating the Borla system completely but I will be using a Magnaflow instead. In theory it should work. I attempted it with this but it didn't work. ProModMike (Exhaust Genius) thinks the issue is that there is still too much pressure resulting in sound. Basically because of the size of our stock muffler and attached resonator, it dampens the v4 drone and chopper sound. It exists in the exhaust system, you just can't hear it because of the dampening. Borla doesn't have a resonator attached but what they DO have is a J pipe that bypasses the adaptive valve which allows more air to move through the pipe. This might compensate for the pressure differences and reduce the chopper and drone sound while maintaining muffler sound.

 

More to come in the next few weeks! ProMod knows what he is doing so I'm going to let him give it a shot first then if all goes well ill add one to mine since I have a different magna flow. It would be nice to have an option that allowed us to keep our AFM, get a loud ass muffler, and spend $250 instead of $1100 for a kickass exhaust.

Are you saying that relocating the flapper valve did not solve the “helicoptering” in v4 mode? 

[Justin Nachazel]

Are you saying that relocating the flapper valve did not solve the “helicoptering” in v4 mode? 

That’s correct it did not solve the problem but I can honestly say it reduced it quite heavily. I can barely hear it and honestly I don’t even notice it anymore

[Bsass220]

1 minute ago, Justin Nachazel said:

 

That’s correct it did not solve the problem but I can honestly say it reduced it quite heavily. I can barely hear it and honestly I don’t even notice it anymore

 

That’s good news, I’m having a borla xs pro installed tomorrow. Going to have them relocated the flapper valve to in front of the muffler. I am also going to leave the resonator in place. Hopefully that’ll do the trick.

[Justin Nachazel]

That’s good news, I’m having a borla xs pro installed tomorrow. Going to have them relocated the flapper valve to in front of the muffler. I am also going to leave the resonator in place. Hopefully that’ll do the trick.

That resonator is going to eat all that sound :/ in the end I pinned my flapper valve open because it wasn’t loud enough. If I could do it again I’d have just had them take it out.

[Justin Nachazel]

That’s good news, I’m having a borla xs pro installed tomorrow. Going to have them relocated the flapper valve to in front of the muffler. I am also going to leave the resonator in place. Hopefully that’ll do the trick.

Here’s mine

[GMBRIAN]

So I would be correct in saying if I removed the resonator only, left the flapper, I could get better sound and no "chopper" noise?  Just want to experiment before dropping big coin on exhaust system if the "chopper" sound is gonna drive me nuts.  That's been my only hang up all along.

[Jaychevy81]

Yea I’m in the same boat deciding what to do but I ordered a Magnaflow cat back system #15360. I’m gonna take the stock exhaust out in one piece that way if it’s unbearable I can put it back and return the Magnaflow. My only other option was GM Borla with the flapper but I wanted duals out each side. They only have out the back or on one side. Why not both sides I have no idea lol. So we will see how this goes.


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[Bratbowtie]

Well gentleman I have been reading exhaust posts for about a week, the more read the more I'm confused, , I want a quiet no drone no chopper sound,  in cab and a low deep pitch just a nice smooth deep tone,.the more I read the more I'm confused. I thought I could get buy with a simple muffler swap not a $1200 cat back system, but there seems to be no set answer,  anyone have any updates,  just the flapper in flapper out debate goes un solved???, 

[Jaychevy81]

Each muffler setup placement resonator delete or leave in. Is gonna leave a diff sound also the drone may sound diff to some and not to others. I spent the 1200 on a cat back system and I turned off V4 and I love it. It I also wanted the dual black pipes kicked out behind the tires so it wasn’t just about a sound. There are a ton of diff ways to go about it. I also wanted it one and done I didn’t wanna try this one or that one. I have that deep growl on start up and when your on the gas but on the highway or light throttle you can’t even tell there is a exhaust system on the truck and it looks nice to.


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[KARNUT]

Well gentleman I have been reading exhaust posts for about a week, the more read the more I'm confused, , I want a quiet no drone no chopper sound,  in cab and a low deep pitch just a nice smooth deep tone,.the more I read the more I'm confused. I thought I could get buy with a simple muffler swap not a $1200 cat back system, but there seems to be no set answer,  anyone have any updates,  just the flapper in flapper out debate goes un solved???, 

I put exhaust on every truck I’ve owned. I used the same bender for 40 years. My 14 GMC. The first thing I did was muffler delete, everything else in place. Then I put a magaflo muffler on. The results, anything other than stock chopper sound in V-4. Then I did what I always do, I bought a hand held tune and turned off cylinder deactivation.


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