Dual-Mode Exhaust for the Z?
 

Here's an interesting idea from the 'Vette people: a dual-mode exhaust. Flip a switch, and it goes from a quieter exhaust to full-performance roar. Old press release here:

Jalopnik - Yeeha!! 2008 Corvette Gets Big Boosts of Both Power and Torque - 2008

Will there be a similar system for the Z? Could be especially useful for those of us who want performance upgrades, but the cops hate the roar...

I had that system on my Corvette. Came out in '08 and has become very popular. Vacum controlled actuators open or close a direct path for the exhaust, routed within the muffler. Closed, the exhaust routes through chambers and is quiet, opened it is almost a straight thru path. Doubt there will be a Z system as it's fairly complex, but an easy solution would be to mount electric cut-outs on the two tubes leading to the muffler. These are pretty trouble free these days.

On the Vette, you can see the two inner pipes and the flaps and actuators that control the sound.

http://images33.fotki.com/v1138/phot...MG_0692-vi.jpg

how it worked
 

I was wondering how it worked on the Vette.

Thanks,
:tiphat:

My father has the same system on his Z06. He opted to install a "man switch" that opens or closes the system with the flip of a switch in the cabin.

At the risk of sounding ignorant...

I'm not sure you would really want e-cutouts. The amount of lowend you would lose would be fairly significant due to the lack of exhaust velocity. Also, your AF might be thrown out of whack if you have other mods. (probably not dangerously lean but possibly leaner than you would want to run the engine over the course of 100,000 miles). The flip switch system might be a better idea but i'm not sure how well the VQ would respond to straight pipes (my inclination is to say "not well"). I suppose it all depends on the stock ECU and other factors.

Then again, I could be off base by a long shot. Maybe somone else has something to add/clarify/correct?

Several guys yanked their rear muffler last week and did some Vids. Honestly it was not that much louder than say a Stillen which led to the conclusion that most of the performance and noise restriction was in the restrictive cats. The car runs very rich to begon with. Dyno's posted here with several exhaust mods still showed relatively rich A/F ratios. This ECU has a pretty broad adaptation range as well which is why they are responding so well to mods without re-tuning.