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Most likely not. It will default to loud - valves open.
Not only will it not retain it's last setting, it will go from quiet mode to loud if you rev the motor above the switching rpm(about 3500). It will stay in loud mode even down to idle until you hit the remote button for quiet mode again. The reason this device does not work as advertised is that it relies on the 12volt signal for its remote receiver power and since the 12volts goes away when you rev the engine the relay in the device drops out thus sending the output to 0volts which is the loud state. To make this device work properly the designers need to supply the circuits with an independent 12volt circuit. I have made this mod on this device. I a few guys have noticed this problem but didn't understand what was happening. To illustrate the problem just cruise down the highway in quiet mode and the accelerate to get the rpms up to get it to switch to loud. Then pull over and listen to your exhaust, it will be in loud mode. If it worked as advertised it would be in quiet mode. Please notify Jay Leno about this development.
Regards, Warren Wiemann
I don't understand what the advantage of this is over the controls the car already has with the mode switches, and the exhaust options in the menus. I have a z51 with npp
I still don't understand what the advantage of this is over the controls the car already has with the mode switches, and the exhaust options in the menus. I have a z51 with npp
The NPP is not always loud in Track Mode, as previously posted earlier in the this thread so this will make it loud when you want it, all of the time, or not by pressing buttons on the remote or Homelink visor buttons if so equipped.
I still don't understand what the advantage of this is over the controls the car already has with the mode switches, and the exhaust options in the menus. I have a z51 with npp
will allow you to switch between rear NPP valves open 100% of the time or normal computer control of the valves. It will not force them to stay closed.
I run with computer exhaust mode set to Stealth (2015 C7 Z51) and use the circuit to remotely open the valves when I want more noise.
The circuit RPI is selling appears to be exactly the same as the one I describe earlier but since I don't own a copy of theirs, I can't be sure it operates the same as mine but I suspect it does.
So this is like pulling the 42 fuse, but, when we want to close the valves we can without having to put the fuse in again.
-Josh
All the circuit does is remotely remove or reinstall the NPP valve fuse. With the fuse out, the valves are open ALL the time. When the fuse is in, the valves will respond how the computer thinks they should - could be open or closed depending on driver mode and exhaust mode setting and throttle application.
When the car is started, the fuse will be removed by default.
Last edited by Skidplate; 12-02-2016 at 02:11 PM.
Reason: update
All the circuit does is remotely remove or reinstall the NPP valve fuse. With the fuse out, the valves are open ALL the time. When the fuse is in, the valves will respond how the computer thinks they should - could be open or closed depending on driver mode and exhaust mode setting and throttle application.
When the car is started, the fuse will be removed by default.
Skid plate, please do not take offense to this reply. I just bought a newC7 with z51. I got very interested in your NPP circuit and went out and got the parts to build one for my car. When I reviewed your thread and all the work you guys did to show and explain the installation I realized there was a problem with the design and implementation.
The implementation will not work properly in the quiet mode. Here is the reason. When in quiet mode if you race the engine over 3500, like when starting or passing or anytime the engine goes over 3500 the circuit will go to loud mode. This is because the fuse circuit goes to 0 volts. This causes the relay to drop out. You must now push the remote button again to get back to quiet mode. This means you will be hitting the remote every few minutes if you want to stay in quiet mode.
The way I fixed this problem was to supply the remote relay circuit with 12volts from another fuse. This required me to separate the relay circuit from the remote receiver circuit. If you guys are interested I can send you some pictures and instructions on making this thing work as it should. Without this fix you may as well just pull fuse 42 since you will be in old mode most of the time.
Sincerely,
Warren Wiemann
I disagree. I want it so I can go loud when I want and when cruising on the highway when I want quiet I can push the button and get there without opening the hood and pulling a fuse. I do understand what you are saying and your fix appears to be what was originally intended but there are some already using it and it does what they, and I want - mine is going in this weekend.
Skid plate, please do not take offense to this reply. I just bought a newC7 with z51. I got very interested in your NPP circuit and went out and got the parts to build one for my car. When I reviewed your thread and all the work you guys did to show and explain the installation I realized there was a problem with the design and implementation.
The implementation will not work properly in the quiet mode. Here is the reason. When in quiet mode if you race the engine over 3500, like when starting or passing or anytime the engine goes over 3500 the circuit will go to loud mode. This is because the fuse circuit goes to 0 volts. This causes the relay to drop out. You must now push the remote button again to get back to quiet mode. This means you will be hitting the remote every few minutes if you want to stay in quiet mode.
The way I fixed this problem was to supply the remote relay circuit with 12volts from another fuse. This required me to separate the relay circuit from the remote receiver circuit. If you guys are interested I can send you some pictures and instructions on making this thing work as it should. Without this fix you may as well just pull fuse 42 since you will be in old mode most of the time.
Sincerely,
Warren Wiemann
I don't have the problem you seem to have, 2015 Z51. My relay only responds to button presses to energize it or not. It does not drop out under any conditions.
The circuit installs or removes the NPP fuse. There is no quiet mode, per se. With the fuse in, the exhaust will do what GM programmed it to do depending on what setting you have set the exhaust to. In my case, I have the exhaust set to Stealth mode. With the fuse 'in', the NPP valves will stay closed at all RPMs, even full throttle, no need to reset anything. I click once for loud all the time and click again for Stealth mode (exhaust stays quiet all the time - driving **** set to Sport).
What mode is your driving mode (**** on center console) set to (Track, Sport, Tour, etc.)? And what mode is your exhaust set to (Auto, Stealth, Tour, Sport or Track)?
Did you buy a '17? Does it have Stealth mode as an exhaust setting?
Last edited by Skidplate; 12-02-2016 at 09:53 PM.
Reason: Added pics
Skidplate is correct. M2W is just a switchable electronic version of the fuse being in or out. With the fuse in (M2W "on"), the car does what GM programmed NPP to do with valves cycling between open and closed depending upon throttle, rpm, etc., as well as what menu choice you've made (e.g. Tour, Sport or Track).
I think part of the confusion is how people have their mode menu set up. Another part of the confusion is that various MYs have different menu options. For example, in my '14, I only have two menu choices for NPP, either "mode dependent" or "off." "Off" is generally loud most of the time, but the valves still cycle between open and closed.
With the fuse out or M2W "off" button, they never close.
I don't have the problem you seem to have, 2015 Z51. My relay only responds to button presses to energize it or not. It does not drop out under any conditions.
The circuit installs or removes the NPP fuse. There is no quiet mode, per se. With the fuse in, the exhaust will do what GM programmed it to do depending on what setting you have set the exhaust to. In my case, I have the exhaust set to Stealth mode. With the fuse 'in', the NPP valves will stay closed at all RPMs, even full throttle, no need to reset anything. I click once for loud all the time and click again for Stealth mode (exhaust stays quiet all the time - driving **** set to Sport).
What mode is your driving mode (**** on center console) set to (Track, Sport, Tour, etc.)? And what mode is your exhaust set to (Auto, Stealth, Tour, Sport or Track)?
Did you buy a '17? Does it have Stealth mode as an exhaust setting?
Skidplate, since I just got my new C7 I was not aware of the sound management feature. I had a C6 for 9 years and I was stuck adding a Borla cat back system. Just kidding it sounds super. Thanks for the input. I will mess with the sound management and learn about it's features.
Thanks again,
Warren Wiemann
12-02-2016, 11:30 AM
