Npp
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Intermediate
Joined: Apr 2011
Posts: 36
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Npp
Just purchased a 2016 2lt Stingray A8....has the NPP option. Haven't tagged it yet. The book doesn't say much about the NPP. Does the ecu control the exhaust...do I need a mild to wild switch?? Love the forum!1
Race Director
Joined: Apr 2000
Posts: 15,344
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From: Texas
Different modes have different open/close parameters. You can set the exhaust to follow the mode selector....ie it'll switch from Tour to Sport to whatever....based on what mode you select or you can set the exhaust to remain in the mode of your choice regardless of what mode you select.
In "Track" mode the exhaust is open except for some very narrow areas across different gears and rpm ranges in order to limit drone. If you want it open all the time, pull the fuse. You can use a "Mild to Wild" but with all the mode selections or the option to pull the fuse, I think it's a waste of money. A MUCH more expensive alternative is to change the tune.
Racer
Joined: Mar 2022
Posts: 438
Likes: 249
From: Tx
In my M7, if the RPM drop under 1500rpms then it will close the valves. They re-open when I reach 1500 or above.. this may be what you're referring to when you ask if the ECU controls this. I go into my settings and set the exhaust settings on Track and it still does this. But I don't mind it.
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
In my M7, if the RPM drop under 1500rpms then it will close the valves. They re-open when I reach 1500 or above.. this may be what you're referring to when you ask if the ECU controls this. I go into my settings and set the exhaust settings on Track and it still does this. But I don't mind it.
Here's the Track mode open positions by gear and RPM. "-1" is open. "100%" means the valves are closed unless you go to 100% throttle
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Race Director
Joined: Apr 2000
Posts: 15,344
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From: Texas
Sport and Tour have another set of tables. "Sport" is below with another range of when the valves will be open or closed.
Tour has the valves closed even more so...
The above are only the opening tables (I didn't post "Stealth mode" btw). Then you get into closing parameters
This is the menu...
The bottom line is that it's not just a simple black and white answer. If the valves are being closed, then there are certain parameters being met. In general however, "Track" will be open with few exceptions. More than one person has gone to the mat swearing that they were in "Track" mode and the valves were closing only to find they had changed the setting in the menu to lock it to Sport or Tour.
Melting Slicks
Joined: Jun 2019
Posts: 2,069
Likes: 950
From: near philly
If you read the table you'll see that if the car is between ~1000 and ~2500rpm in 4th or 5th gear, the valves close. That's to prevent drone. You'll also note there are undefined values since other parameters can cause them to close. The "%" values are not how much the valves are open, it's throttle position.
Sport and Tour have another set of tables. "Sport" is below with another range of when the valves will be open or closed.
The above are only the opening tables (I didn't post "Stealth mode" btw). Then you get into closing parameters
This is the menu...
The bottom line is that it's not just a simple black and white answer. If the valves are being closed, then there are certain parameters being met. In general however, "Track" will be open with few exceptions. More than one person has gone to the mat swearing that they were in "Track" mode and the valves were closing only to find they had changed the setting in the menu to lock it to Sport or Tour.
Sport and Tour have another set of tables. "Sport" is below with another range of when the valves will be open or closed.
The above are only the opening tables (I didn't post "Stealth mode" btw). Then you get into closing parameters
This is the menu...
The bottom line is that it's not just a simple black and white answer. If the valves are being closed, then there are certain parameters being met. In general however, "Track" will be open with few exceptions. More than one person has gone to the mat swearing that they were in "Track" mode and the valves were closing only to find they had changed the setting in the menu to lock it to Sport or Tour.
I know the other modes close a lot of times, but not track mode.
I seriously doubt the previous owner tuned it to perform differently being he sold it at 1800 miles to me
Race Director
Joined: Apr 2000
Posts: 15,344
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From: Texas
You've proven my point. Go read the valve mapping and think about what it says. Then think about what I also said that there are other parameters that factor in and that the valve opening/closing is not a simple on/off based on what you see in the maps.
Melting Slicks
Joined: Jun 2019
Posts: 2,069
Likes: 950
From: near philly
Nobody ever once said that any mode is either always closed or always opened.
That's why we said in Track mode it's always open other than 5th gear below 1400 rpm's, which achieves the goal of having the valves open "basically" all the time.
If someone were extremely concerned about that tiny section of operation closing the valves they can pull the fuse.
If you don't care about sub 1400 rpm use in 5th gear then just select track, period.
This is the for the manual trans. I can't speak to how it works in the auto but I'd guess it's pretty darn close.
Race Director
Joined: Apr 2000
Posts: 15,344
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From: Texas
I proved what ChodaBoy said which I confirmed as the function of mine. You are the one that suggested that was incorrect and it must have been "tuned" to change the factory functioning.
Nobody ever once said that any mode is either always closed or always opened.
That's why we said in Track mode it's always open other than 5th gear below 1400 rpm's, which achieves the goal of having the valves open "basically" all the time.
If someone were extremely concerned about that tiny section of operation closing the valves they can pull the fuse.
If you don't care about sub 1400 rpm use in 5th gear then just select track, period.
This is the for the manual trans. I can't speak to how it works in the auto but I'd guess it's pretty darn close.
Nobody ever once said that any mode is either always closed or always opened.
That's why we said in Track mode it's always open other than 5th gear below 1400 rpm's, which achieves the goal of having the valves open "basically" all the time.
If someone were extremely concerned about that tiny section of operation closing the valves they can pull the fuse.
If you don't care about sub 1400 rpm use in 5th gear then just select track, period.
This is the for the manual trans. I can't speak to how it works in the auto but I'd guess it's pretty darn close.
