How does the Performance Exhaust work?
 

Has operation of the performance exhaust option changed from the C6 to the C7? Can the sound be changed by the driver mode selector or how does it function? Are there more options than fully open or fully closed? I see a lot of speculation out there but does anyone have the hard facts?

If you went to the video on the link below you will see Dave Tatman briefly demonstrate how the exhaust note is changed between sport and tour

http://www.corvetteblogger.com/2013/...rvette-museum/

Thanks, I had not seen that video. It does demonstrate the change in exhaust tone by the mode selector. My dealer told me that it would not function that way but I still had hope based on what I've read.

That's correct. The video was helpful. The performance exhaust system, code NPP, opens two more valves for the jump from 455 to 460 HP.

Now four valves on NPP exhaust. All together you get city, stealth, eco, tour, weather, tour, sport and track (7) different exhaust options.

So, it looks like the NPP extra valves may be opened up using the driver mode selector and not just at higher RPM's. If I don't have the performance exhaust does the driver mode selector still alter the exhaust sound? What are the city and stealth options and how are they selected? I did not add the NPP to my order but I'm thinking that was a mistake I still have time to correct.

Z51, NPP, MSRC, 7 speed....SWEET!! Go for it...

Yes, even if you do NOT have NPP, the driver mode selector alters the exhaust, giving you five different exhaust sounds.

Actually I think it sounds like one more thing to go great :sm0:I can't wait to get mine with the performance exhaust. :headbang:

This is a little off topic in this thread, but I didn't feel like it warrants another thread on its own. In that same video it showed a chart of the changes made by the driver mode selector. In ECO mode it shows AFM in an "eco" setting. So does that mean you can choose ECO and keep the engine in 4 cylinder mode no matter what? I think that would be a fantastic idea to save on gas when you have no intention of getting sporty, I may mandate my wife uses ECO mode whenever she drives it :)

A little reasoning behind that desire: It will probably be shocking how much power it still has. I can't imagine how fun it would be to beat some cars off the line with half my engine doing the work. Just my thoughts on that. Plus it's an average of 4.50 a gallon over here in Hawaii for premium. So being able to cruise over for dinner out with the lady and get mid to upper 20's mpg would save me the tip on dinner. LOL. As much as MPG is hated on in forums for the most part, people I talk to are just as impressed by high MPG numbers as they are by HP and TQ numbers, sometimes more so. I'm keeping my fingers crossed for my 460HP, 455LB-FT, and 30MPG highway. How incredible that would be.

In other than ECO mode, the engine will use all eight cylinders, while in ECO mode it will use all eight except in certain situations related to highway driving. That would make using engine management a choice. I understand your idea but I do not see it viable in a reasonable way but given the steady advance of technology I can easily see it in the next generation Corvette engine.

One reason I see it coming is the incredible need to accommodate mandated emission and mileage requirements. In fact, those requirements would be the only reason AND such technology would keep V8 engines available for Corvette and other premium sport cars.

Laborsmith

Thanks for that dose of reality, I didn't think about how its actually more efficient to barely use the power of all 8 than stress 4. Just good for steady cruising. Also a very interesting, and also very true statement about AFM technology saving V8's. That's encouraging, I think everyone was worried about the market disappearing due to these regulations. I'm not thoroughly versed on it, do the regulations just say "MPG needs to be X and if its not, you have to pay Y tax on the car"? Just extending the gas guzzler tax?

Much more complex than that and related to carbon footprint. The regulation is hundred of pages long, if that gives you any idea.

Laborsmith