Found this on ebay 🤔 but I didn't see it on m2w site.

https://www.ebay.com/itm/28486532307...mis&media=COPY


TL;DR Update
Disconnected all 4 valves, keeping them open at all times. Result: not loud enough for me, and any improvement wasn't significant enough to pursue further.

That muffler, though seemingly simple internally, must be very restrictive!! Biggest change was the odd exhaust sounds if it goes in V4 mode.

Cleared 10 codes. Time for another solution.

Something on my wish list for an "intelligent" upgrade is a *true* stealth startup. It's the loudest when I'd prefer it to be the quietest 🙄...

So: removing fuses, keeping valves open, etc, etc, will *not* work better than "Track". That chapter is closed.

 

From all of the reports we have seen on the forum the M2W for the C8 doesn't work - even though the company who makes it says it does.

 

M2W is also unnecessary for the C8

 

​​​​​Thanks, i suspected this was the case.

I think to call it "unnecessary" is both subjective and contrary to what we know of how the npp/afm valves operate.

Chevy own documentation states that the valves will close at certain times to meet "drive by" noise requirements.

That means it is necessary for those who want those valves to stay open, rather than spending $2000-5000 on a muffler.

 

I can't believe no one has figure it out yet.

 

Indeed. I'm about to hope to figure it out when I get the C8 back in my garage

 

To many error codes thrown by M2W on my C7. Will not be back...and as others have said ^^^^^ I don't find it as necessary on the C8.

 

Thank you.
If the OP wants it loud all of the time, then I recommend he get another (much more expensive) aftermarket exhaust.

 

Perhaps I should have said “it’s not necessary unless…”

Unless you want the bold in your post above. You are likely going to have to spend coin on a new exhaust if the NPP is not loud enough for you and/or you want the valves open all of the time.

 

GM in complying with regulations and wanting to avoid having to deal with a recall, might have overshot the mark on the safe/quiet side. I certainly think this is the case, because my c8 has the least inspiring exhaust note of any of my 7 vehicles.

You could say I have this crazy idea that I should try spending some time on a potentially very low cost solution before spending thousands on a muffler.

I dont mind finding out for myself, (either wrong or right) especially given that nobody has really "solved" this except for those who have a $$$ interest in selling you a $2000-5000 muffler.

I'm a retired engineer with background in electronics and mechanical. I have that luxury of time to experiment and enjoy it too.

 

Seller is CorvetteMods. Buyer beware! They were kicked off this forum.

 

This OP will be back with another thread bemoaning getting scammed by Corvette Mods. And being retired, he has plenty of time to whine.

 

I've had the M2W on my 2016 C7 since it was new and it has been flawless the entire time.

 

Theres no need to be immature. I know you're jealous or intimidated by my free time and credentials. Are you in the $5000 muffler business? 🤣 ...speaking of not getting scammed... oh don't worry I won't put you out of business I promise 😄. It just takes longer for some folks to grow up.

 

Good luck with finding a satisfactory solution to get what you want out of your C8

 

thanks 👍

 

You’re welcome. Sincerely.
If you find that solution, be sure to share it here.

 

Have you noticed the NPP valves closing in track mode? The drive by requirements are for steady-state conditions under certain speeds. Any increase of throttle will open the valves. I have not noticed the valves closing in track mode but I normally only use the track exhaust setting during spirited driving. Your first step may be finding out when the valves close to get an idea of how much of a difference it would make to keep them open. You could temporarily remove the actuators from the exhaust (keep them connected and wire them out of the way - the NPP valves are spring loaded to the open position). You will eventually throw a code but it will give you an idea of how much difference it makes.

 

Yep this is my plan. Will stick a camera down there to record it, for starters.

 

Keep in mind that your goal is not to "keep the valves open" but rather to achieve what you perceive as a louder exhaust. Louder than ......? With the engine/shift setting to tour, the car will go intoV4/ AFM mode. It will close the pair of AFM valves in the exhaust system, as well as the exhaust flow control valves. If you find a way to keep the exhaust flow control valves open, will it be louder, or will it make an unpleasant sound? Ok. So, then consider driving in Z-mode (or manual mode) - and setting the engin/shift to track mode. That will keep the car out of AFM mode. And it will shift more aggressively, up and down, and the automatic gear selection will favor higher rpms for given speed. Now with the engine sound set to track, the exhaust flow control valves will be open almost all the time. They may close if you cruise at steady speed, no acceleration, and below some RPM (keeping in mind the the gear selection now favors higher RPM). But its not clear that there will often be conditions where the perceived exhaust note would be louder than just using those settings. If I were a "retired engineer with a background in electronics and mechanical" I would start by finding a way to just disconnect the valve actuators from the valves and tie the valves open - then drive around and see if I can hear any difference that makes me want to automate the process. You could also experiment with tieing both sets of valves open (AFM and exhaust flow control valves). You might get DTCs but for test purpose just ignore them. If you like the result you can automate it.