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Running in Eco mode in the M7 or any mode in the A8 in automatic operation will result in AFM kicking in, which will be much more noticeable while driving with NPP in Track mode. Driving with NPP in Sport will mask this completely as in Sport the exhaust is open most of the time, but closed at highway cruising rpms.
One other point, on stock exhaust running in Track mode all the time on an M7 was great, but once I went to a Borla x-pipe to remove the secondary cats, the drone at highway speeds is borderline irritating for me, and definitely irritating for the wife.
I agree with this. Another reason I installed the Mild2Wild switch. When cruising on the highway in 7th gear I close the valves and there is zero drone. Works like a charm.
2020 Corvette of the Year Finalist (performance mods)
C4 of Year Winner (performance mods) 2019
Originally Posted by Avanti
I've no problem being what I suspect is a contrarian... I strongly dislike loud exhausts, period.
That's the funny thing, even in Track mode the C7 is quieter than my previous C6 was with the valves open. But I definitely know how you feel, sometimes I just want to put it in Stealth or Tour and not hear it. What was really fun was on my previous C6 GS that had ~800HP (blower): use the Dashlogic I had to put it in "stealth" mode (valves closed even at WOT) and do some pulls. People would think it was stock, and then they'd just get totally walked.
Just another great part of this car.The adjust ability of:The Sound Of Music...
When the mrs. is riding shot-gun.The Car in auto.Range In,Touring Mod Selected.
Country Music half the ride.
When Solo.Tranny in Manual,Range In,Touring and or Sport depending on the road surface.Track ain't happening around here.Alternative and or Classic Rock on Pandora.
Now you know it has a AWE X-Pipe with no rear cats.
The Tunes are so much Better
Fuse 41 (2014) or fuse 42 (2015+) controls NPP valves. Pulling the fuse will NOT cause a CEL, nor will pulling the connectors at the valves. These two NPP valve disable methods are electrically identical, but the fuse pull is simpler and more easily reversible.
The fuse is located in the fuse box on the passenger side in the engine compartment. My fuse is now in a baggy in the glove box!
Pulled the fuse. Eliminates the valves briefly closing around 1500 RPM. If you need it quiet, put it in Economy mode.
The valves don't close around 1500 rpm. I have driven many miles with my exhaust set in track mode and when not in Eco Mode the only time I think I have heard the valves close was around 35 mph while the transmission was in 5th gear. They definitely don't close at 1500 when the transmission is in any of the other 6 gears. They also don't close around 35 mph in any other gear either. I think they close around 35 mph in 5th because if I am driving in town in that gear and decide to accelerate and push the throttle wide open I hear a loud pop and more noise after the pop which I think happens when the valves open. When I run in Eco Mode the exhaust will switch from loud to quiet when the engine switches to 4 cylinder mode and then gets loud when it switches back to 8 cylinder mode. If it is in 4 cylinder mode with the valves close and I go wide open I hear the same pop. I don't think AFM activates in gears 1, 2 or 3 since I have never heard it activate in those gears. With an M7 all pulling the fuse does is let you hear the engine running in 4 cylinder mode which doesn't sound all that great.
Fuse 41 (2014) or fuse 42 (2015+) controls NPP valves. Pulling the fuse will NOT cause a CEL, nor will pulling the connectors at the valves. These two NPP valve disable methods are electrically identical, but the fuse pull is simpler and more easily reversible.
The fuse is located in the fuse box on the passenger side in the engine compartment. My fuse is now in a baggy in the glove box!
You gotta be careful what read on the interweb! Sorry if I passed on misleading information. I was going from memory before I pulled the fuse. Apparently, the closing in any mode is speed related not rpm related as I incorrectly stated.
"The NPP exhaust in track mode meets all FEDERAL sound standards. The federal test is a drive-by at speeds of up to 35 mph in the tallest gears that can be used at that speed. Even in track mode, the NPP valves close partially at speeds below about 36-37 mph in certain gears in order to meet this standard. "
I have the fuse pulled AND I run the soler throttle controller. Makes a big difference with this combo, I can now hear it burble and the noise of the acceleration and downshifting is noticeably louder. In my opinion it's in supercar/Lambo exhaust sound territory. No more need to modify the exhaust, the sound is just right, I've had a truck follow me and he screamed beautiful sound!
You should run it in the garage, exhaust facing the closed end. Plug the fuse in, and pull it out, you’ll hear the difference. It is very noticeable, just ask my neighbors and little kids at the ice scream stand.
LT headers and xpipe with no cats, A&A supercharger, M2W with valves open all the time except early morning cold starts (for my neighbors). Loud as heck, and I love the sound! When I close the valves it's quiet as a kitten's purr.
One thing most people don't mention... I had a drone on 8th gear when lugging on an slight to mild incline. Put in a Circle D 3400 stall torque converter for other reasons, but the drone went away for good.
I did something that hasn’t been covered. If you have access to HPTuners you can license the Chassis Control Module (2 credits) and program the different modes to whatever you want to. I set the Track mode to leave the valves open 100% of the time. I set Stealth mode to close the valves 100% of the time. I left the other Tour mode etc. factory.
I can use the Mode setting **** on the console to quickly choose Track for loud mode when rolling. Or, if I don’t want to endure the stiff ride (I have the magnetic shocks) I can use the touch screen to select the Track exhaust mode to be loud in any mode. Or, Stealth to be quiet in any mode (including Track).
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Slideshow: A Jaguar designer's personal project imagines what a modern front-engined Corvette might look like if Chevrolet revisited the golden age of the Stingray.
