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Hi All, My wife just purchased a 2019 Grand Sport M7 and she'd like to drive with the exhaust open full time in mainly Sport Mode. I ran across a video on YT that showed pulling Fuse 42 disables the software control of the exhaust valves and keeps them wide open in "default mode" full time. Just curious whether anyone else has done this and if there are any unintended consequences? TIA!
That will probably work but isn't necessary since you have an M7. Use the settings menu in the center display and go to the Vehicle Personalization Menu, choose Drive Mode, then choose Engine Sound Management followed by selecting Track. This will place the exhaust in permanent open mode. It will be open all of the time except when running in Eco Mode when it will close every time the engine switches to 4-cylinder mode. If you are driving in Tour, Sport or Track the exhaust will be wide open all the time except for one condition which is less than 1500 rpm when driving 5th gear. For some strange reason, this only applies to 5th gear. When GM designed the system they decided the exhaust sound was objectionable when running in 4-cylinder mode and that is why the valves close when the engine is in that mode. The reason the people with automatics run into the valves closing more often is because the automatics run in Eco Mode all of the time unless the transmission is placed in Manual Mode.
What you will notice is the exhaust will not make as much noise when you are driving around at low throttle openings low load conditions such as on the street or highway. However, the valves are still open. I have found with my 2015 the exhaust got louder the more track miles I put on the car. So even at idle or at part throttle it still has some volume and forces me to put the exhaust in stealth mode when I am on a trip running with the cruise on in 7th gear at 80 mph. If I don't put it into Stealth Mode I can't hear the radio.
Thanks Bill, really appreciate your detailed reply. My understanding was that even with the Engine Sound Management set to "Track" that the software controls would still actively close the valves in certain conditions like you mentioned in 5th gear to meet Federal drive-by noise restrictions. But we'll try this and see how it sounds. Thanks again, Cheers!
Pulling the fused labelled as EXH2 (fuse number varies by year as noted above) on the fuse schedule in the manual or the fuse box lid will not cause any codes, errors, or check engine light. The exhaust will sound like crap if you drive in ECO and go into 4 cylinder mode with the NPP valves open.
Pulling the fused labelled as EXH2 (fuse number varies by year as noted above) The exhaust will sound like crap if you drive in ECO and go into 4 cylinder mode with the NPP valves open.
Ron
Thanks Ron! My wife promises not to go into ECO mode with the EXH2 fuse pulled! She’s definitely not into burned rice farts! Lol!
Thanks Bill, really appreciate your detailed reply. My understanding was that even with the Engine Sound Management set to "Track" that the software controls would still actively close the valves in certain conditions like you mentioned in 5th gear to meet Federal drive-by noise restrictions. But we'll try this and see how it sounds. Thanks again, Cheers!
it's just 5th at that one rpm and below, which is almost non existent
no need at all to bother with that fuse, they'll always be open with the manual
One down side to pulling the fuse will be the annoying boom when coming in and out of 4 cylinder mode. It drove me nuts until I added a tune to keep it in V8 mode all the time. You could also use a Range device to do so without need for a tune.
As Bill mentions, just setting the exhaust to Track mode is the easiest way to do. There is a Very small area of the envelope where the flaps will close.
Below is a screenshot straight from the Active Exhaust map in my 2019 Grand Sport. Other years/models will be nearly (or are) identical. 2014 may be the outlier since it was a bit different. The exhaust flaps are open in all the areas you see "-1" They are closed in the areas you see "100%"....unless you go to 100% throttle....in which case the flaps will open in those regions as well. I haven't explored "undefined" but what the values mean is that above that percentage of throttle (ie 40%), the flaps will open. My guess is that area of the table is some combination of engine load and speed in addition to rpm and gear selection in order to address the drive-by noise requirements.
I went ahead and pulled the fuse and went on a road trip over the weekend with no issues. Since its an M7, we'll just stay out of ECO mode and avoid the farty 4 cylinder exhaust note.
I thought about pulling mine but I like being able to put it in Stealth mode for 430am drives to the gym. My exhaust points directly at the neighbors bedroom window when I back out of the garage so I try to be nice. M7 in track mode is plenty loud although I think I like Sport more for every day driving, less drone at Hwy speeds.
I recently purchased a 2014 Stingray with NPP. The options that I have for Engine Sound Management are 'adjust to drive mode' (or something similar), and 'Off'. Would putting it in the 'Off' mode keep the valves open, or constantly closed? My previous C6 had a Borla exhaust and I loved the sound. Wanting something similar (not tone-wise, but volume) from the NPP, just not sure if pulling the fuse accomplishes that, or putting the Sound Management in 'Off', or drive mode is the best way?
Engine Sound Management OFF is essentially TRACK on 2014s. The valves will still be closed under some conditions. Removing EXH2 fuse (#41 for 2014) will keep the valves open all the time.
05-29-2023, 01:49 PM
Pulling Fuse 42 to run Open Exhaust full time?
