What's the purpose of these Mufflers???


Dedicated LVC Member
Feb 11, 2008
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What's the purpose of these Z06 Mufflers?...Are the second exhaust ports suppose to close under vacuum and open at WOT?...Are there suppose to be some HP gains or something?

Vacuum assisted secondaries. They're for extra sound and (maybe) power at WOT
Sound... it makes the car quiet around town and while just cruising down the freeway... then when you kick it to WOT it screams, best of both worlds...
Lots of higher end cars use things like that to be quiet for the old foagies but still sound aggressive for the people who rip on them.
Those C6 Z06's sound good. I saw one outside Jamie's shop one time. At idle, the sound was disappointing. (sounded like a rice burner on steroids) But, when opened up, sounded pretty awesome - kind of a ROAR!!! - I was surprised that a factory stock vehicle was allowed to 'get away' with being so loud.
A company performs a mod called "Mild 2 Wild" on the exhaust that allows the user to open the butterflies with the flip of a switch for those who don't like the quieter idle. The new C6 ZR1 has the exhaust butterflies too I believe. Both sick cars.
That's pretty damn awesome.

Quick noob question - I know what WOT means, just not what it stands for. I think my question is clear here. :D
i would assume the muffler is made for that also though.... if you put a butterfly on a magnaflow.... it ends up as loud as a magnaflow... the butterfly on the vette muffler is probably straight through.... i know its damn loud....`
I believe the open pipe is routed through several passages like a standard muffler. The butterflied pipe is straight through. Closed=quiet open= loud+free flowing. I don't know if i'd waste all the $$$ modding the muffler at the end of the system. Actual gains would be made in the beginning to mid section. End of the system is more noise control. Still good to do just not as effective.IMO. In a more straight piped system it would be pretty neat for the noise control if you could find some cheap. What are the take-offs going for? Might be a little headache routing the vacuum line.
for the straight pipe sound at WOT???...that'll give it full flow at WOTand be able to pass emission, awesome!!!
That would do it.... just bypass the muffler.... but you will probably get leaking through the butterfly.
My setup bypasses the mufflers and is entirely automatic. :D


I wired a programmable TPS switch to signal the QTP controller for the electric cutouts. When the TPS shows WOT, the switch triggers the cutout controller to open the cutouts. :cool:

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