2014+ Exhaust Systems & Mufflers

[Strykers_Inc]

Does the front pipe have a valve and bypass pipe on it? If so, can you post a pic.

 

Here is the picture as promised.

[14SLTZ71]

Here is the picture as promised.

Thanks.

The bypass pipe looks small but apparently it does something or they wouldn't put it there. Maybe it's there to ensure trucks up north start in the frigid winter months when the valve freezes shut.

[Strykers_Inc]

I believe it has something to do with backpressure.

 

I think they calculated the exhaust pressure needed in order to open the valve in V8 mode, and when in V4 mode it closes and forces the exhaust around through the smaller pipe which maybe allows the pressure to be maintained within the down pipe reducing the drone.

 

Just a thought.......not exact science or engineering on my part.....

Edited July 30, 2014 by Strykers_Inc

[Daniel T]

I am highly considering getting the dual out the back Borla from Chevy....their part number and still has flapper for V4 mode.

Pretty sure I can get it at a discount from my dealer.

Have considered Gibson and Magnaflow, but feel a bit better about going with a GM endorsed part.

Just sold my 2008 Duramax, so just getting back into the gasser mode...

[skennel23]

Has anyone done a straight pipe set up with a y pipe out to 2 tips in the back. Haven't seen this on a 2014 yet.

[ddmcs14]

Getting the aFe installed today. I'll post pics and clips soon since no one seems to post much about this exhaust

[smpldezine]

I have the aFe installed and love it.. except the fart can tip that comes with it. I replaced it with a 3" in and 3.5" out dual wall mbrp tip after cutting the 3.5 flare off. Its a great sounding exhaust at a great price.

Edited August 1, 2014 by smpldezine

[ddmcs14]

I have the aFe installed and love it.. except the fart can tip that comes with it. I replaced it with a 3" in and 3.5" out dual wall mbrp tip after cutting the 3.5 flare off. Its a great sounding exhaust at a great price.

Does he tip that comes with it stick out too far or are you just saying its big?

[smpldezine]

Both..

 

That flare in the aFe pipe is where I cut it and added the different tip. The aFe tip in the kit is 3.5 in and 4.5 out... ok for a diesel, not a 5.3L IMO.

Edited August 1, 2014 by smpldezine

[Daniel T]

Check out this video from Borla.

At about 38-45 seconds it shows pictures of two exhausts and both show a flapper valve and bypass pipe just. Like the Borla systems you can purchase from GM...

I wonder if you can purchase directly from Borla now?

 

 

[14SLTZ71]

Check out this video from Borla.

At about 38-45 seconds it shows pictures of two exhausts and both show a flapper valve and bypass pipe just. Like the Borla systems you can purchase from GM...

I wonder if you can purchase directly from Borla now?

Borla will not sell you their system with the valve.

I bought their split rear exit behind each tire because GM doesn't offer that version. It had V4 drone and flutter so I contacted Borla directly and asked if they would send me just the front pipe assembly w/valve and was told "we will give you a full refund and then you can go buy the GM version" " we can not provide you with the front pipe assembly that contains the valve, this belongs to GM".

So I took the refund, I think they wanted my exhaust to test anyway, at least that's the vibe I got from our conversation.

You can get the Borla for around $900 and the GM version cost $1250

Edited August 3, 2014 by 14LTZZ71

[Daniel T]

Has anyone considered cutting the valve out of the stock system and then having it welded into a new cat back system on the inlet side like the a Borla GM system...seems you could end up with the same thing minus the small bypass pipe on the GM product.

[14SLTZ71]

I have seen similar valves on ebay if you want to give it a try.

 

http://www.ebay.com/itm/Vehicle-Adaptive-Exhaust-Valve-/230981317711

[Strykers_Inc]

You do realize that these exhausts are tuned....as in frequency tuned... Just adding a valve more than likely will not stop the drone.... Notice the valve being before the muffler on the GMPP Borla... There is a reason there is a bypass pipe.... The stock muffler valve is in my opinion to blowout excess back pressure at startup...

[14SLTZ71]

You do realize that these exhausts are tuned....as in frequency tuned... Just adding a valve more than likely will not stop the drone.... Notice the valve being before the muffler on the GMPP Borla... There is a reason there is a bypass pipe.... The stock muffler valve is in my opinion to blowout excess back pressure at startup...

Yes, I realize they are tuned.

In this video Jeff Luke, Executive Chief Engineer for the Chevy Silverado talked to www.drivingthenation.com about passive flapper valve.

 

http://www.drivingthenation.com/lou-ann-hammond/chevy-silverados-passive-flapper-valves-and-more/