NPP exhaust control
Thread Starter
Drifting
Joined: Mar 2014
Posts: 1,767
Likes: 338
From: San Diego CA
NPP exhaust control
A forum member on a different forum installed a mild to wild device from the C6 onto his C7. I know Theta designed a similar device but it seems this would be an easier solution. I was under the impression the C6 version would not work but he said it works fine. The only modification he had to make was a smaller "add a Circuit" and fuse holder. He said it does not throw any codes and really works well. He also had to put a small hole
in the fuse box to get the ground out and connected. It is controlled with a remote.
I would be curious to know if anyone else had tried this. Hopefully Theta will weigh in. Here is his version.
in the fuse box to get the ground out and connected. It is controlled with a remote.
I would be curious to know if anyone else had tried this. Hopefully Theta will weigh in. Here is his version.
Burning Brakes
Joined: Aug 2014
Posts: 990
Likes: 207
From: Bay Area CA
A forum member on a different forum installed a mild to wild device from the C6 onto his C7. I know Theta designed a similar device but it seems this would be an easier solution. I was under the impression the C6 version would not work but he said it works fine. The only modification he had to make was a smaller "add a Circuit" and fuse holder. He said it does not throw any codes and really works well. He also had to put a small hole
in the fuse box to get the ground out and connected. It is controlled with a remote.
I would be curious to know if anyone else had tried this. Hopefully Theta will weigh in. Here is his version.
Attachment 47921536
in the fuse box to get the ground out and connected. It is controlled with a remote.
I would be curious to know if anyone else had tried this. Hopefully Theta will weigh in. Here is his version.
Attachment 47921536
You could try looking here:
https://www.corvetteforum.com/forums...ob-how-to.html
Basically it will allow an inexpensive method to over-ride the computer and open the rear exhaust valves (NPP) when the computer wants them closed. Obviously, if you command the valves to open and they are already open, nothing happens but when the computer wants them closed, they will not close until you press the remote to re-enable the fuse in the circuit. The circuit will not close the valves if the computer wants them open.
Last edited by Skidplate; Oct 9, 2015 at 08:22 PM. Reason: clarification
Thread Starter
Drifting
Joined: Mar 2014
Posts: 1,767
Likes: 338
From: San Diego CA
You could try looking here: https://www.corvetteforum.com/forums...ob-how-to.html
Racer
Joined: Jun 2009
Posts: 476
Likes: 82
From: Hartland WI
Why is this different from the software control already in the car? I have a 16 Z51 that has software options under engine management to control the exhaust note. Is that a 16 MY option only or ???
Thanks!
Thanks!
Team Owner
Joined: Nov 2007
Posts: 45,272
Likes: 8,545
From: Rochester, NY
RPM's.
I'm Batman..
Joined: Apr 2014
Posts: 6,142
Likes: 921
From: Lehigh Acres FL
Tech Contributor
For those that bought the car without NPP there is no wiring harness under the car to connect the valves and there is no algorithym in the computer tk control them either. The engine sound management option is there but doesnt do anything at that point. M2W provides a way to open and close te valves if you fit into this catagory like me.
Le Mans Master
Joined: Jun 2004
Posts: 6,269
Likes: 50
From: Dallas Texas
St. Jude Donor '06-'07-'09-'10
I'm amazed that nobody has jump on to this and started making M2W units for the C7. There's got to be a lot of NPP owners out there who would go for it, me included. 
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Drifting
Joined: Sep 2012
Posts: 1,446
Likes: 121
From: No Longer in CA! NV
Loved my M2W on my GS, and do wish they made one for the C7. The beauty isn't controlling the opening so much, for me, but being able to close them on demand.
We had some runs where everyone were running a little hot and came upon a Leo, and it was good to be able to quickly slip into stealth mode.
Also good for longer trips when you just wanted to quickly silence the drone and talk with the Mrs., or listen to some tunes, yet be able to be wide open those times you just wanted to hear the engine purr.
Surprised three years into it none of the vendors have worked up a commercial solution.
We had some runs where everyone were running a little hot and came upon a Leo, and it was good to be able to quickly slip into stealth mode.
Also good for longer trips when you just wanted to quickly silence the drone and talk with the Mrs., or listen to some tunes, yet be able to be wide open those times you just wanted to hear the engine purr.
Surprised three years into it none of the vendors have worked up a commercial solution.
Safety Car
Joined: Jan 2015
Posts: 3,941
Likes: 499
From: Northern Virginia
https://www.corvetteforum.com/forums...ob-how-to.html
Racer
Joined: Jul 2005
Posts: 497
Likes: 204
From: Irvine CA
For those that bought the car without NPP there is no wiring harness under the car to connect the valves and there is no algorithym in the computer tk control them either. The engine sound management option is there but doesnt do anything at that point. M2W provides a way to open and close te valves if you fit into this catagory like me.
I'm Batman..
Joined: Apr 2014
Posts: 6,142
Likes: 921
From: Lehigh Acres FL
Tech Contributor
You can make the same thing for yourself, very easily:
https://www.corvetteforum.com/forums...ob-how-to.html
https://www.corvetteforum.com/forums...ob-how-to.html
Not quite. A retrofit can and has been done. I didn't have NPP in my C7 and retrofitted it with the control module from Akrapovic. This module gives with the same integration as the factory NPP with sound management. You can get details here: http://www.akrapovic.com/#!/car/prod...37&yearId=3895
Safety Car
Joined: Jan 2015
Posts: 3,941
Likes: 499
From: Northern Virginia
Forum member theta developed a true retrofit, manual control circuit but apparently ran into some legal issues with GM or one of its suppliers.
Pro
Joined: Jan 2010
Posts: 629
Likes: 65
From: Freedom PA
I converted the Mild to Wild switch that I took off my C6 when I traded it in. Here's the post I made several months ago about the process.
https://www.corvetteforum.com/forums...onversion.html
Ed
https://www.corvetteforum.com/forums...onversion.html
Ed
I'm Batman..
Joined: Apr 2014
Posts: 6,142
Likes: 921
From: Lehigh Acres FL
Tech Contributor
I converted the Mild to Wild switch that I took off my C6 when I traded it in. Here's the post I made several months ago about the process.
https://www.corvetteforum.com/forums...onversion.html
Ed
https://www.corvetteforum.com/forums...onversion.html
Ed
Pro
Joined: Jan 2010
Posts: 629
Likes: 65
From: Freedom PA
This is a functional solution for those that have cars that originally came NPP equipped. For those that didn't originally have NPP, the fuse box can't be used as those cars have no wiring going back to the valves as the car was intended to not have valves in this case. A true solution would be needed that provides the wiring, NPP valve electrical connectors, etc.
Theta's solution to keep the NPP valves closed, or to equip a car, that did not come with NPP, with NPP mufflers was covered extensively in a couple other threads. Unfortunately that solution was shut down after a considerable financial and time investment by him.
Ed