I was just thinking about that....maybe this sounds naive but doesn't the Max contrive some of its ponies through the unique exhaust system?

Something tells me that you can't just run down to Speedy, Meinke or Midas to have a new one put on.

Sounds like a dealer job...how much is that gonna cost???

You can buy mine from me. Any muffler shop can install it. From the B-pipe to the exhaust, there's nothing special, it's the exhaust itself that is unique.

OR

you could buy mine!

It's a matter of two bolts and three rubber hangers.....very very easy

So the extra HP doesnt come from inside the muffler but farther back in the exhaust system....so the miuffler shops would have 2k+ mufflers.

Glad I asked

Yeah, I thought the mufflers had some sort of butterfly valve or something. However, I see a bunch of people putting on after market mufflers. Has anyone done a dyno???

The butterfly mechanism opens to release excess exhaust gases (at lower RPMs). It closes when there is less exhaust to release, so it's quieter. At least, that's what I remember reading about it.

Pretty close, Tanmann9. This is actually what it is and what it does:

"A variable-capacity muffler bows alongside the Maxima's new V6 for 2000. First seen on the Skyline GT-R sports car, this muffler has one inlet pipe and two outlet pipes. At part throttle (less than 2000 rpm), a spring-loaded steel valve directs exhaust to one outlet pipe. At wide-open throttle (more than 2000 rpm), the valve opens and directs exhaust to the second pipe, reducing back pressure by as much as 40%."

Source: Car and Driver Magazine