In for pics, I'm really curious about this too.

 

I just found this. It's a Nissan video showing the variable capacity muffler in action and the purpose of the design. The valve is exactly where I think it should be on the G muffler.

http://www.nissan.gd/B_pop/Navigation/p015_VCM.html

 

Careful, I believe there is a lot of fiber glass or something in there if I am not mistaken thats is very itchy

 

sub'd

 

wow you sedan guys have alot of interesting did you knows

 

actually i think there is asbestos in the exhaust!

 

did udo it yet?huh? huh?

 

My old Maxima had a variable capacity muffler. I did actually cut it open after swapping out exhausts. No fiberglass or such. Just perforated tubes and a big spring valve.

 

Shouldn't be any packing in there, especially asbestos. If there was asbestos in there, I could handle it since I'm a licensed asbestos inspector and environmental consultant by trade

 

Wow I never even heard of a valve in the muffler. I am very interested in this too. Please do post pics up soon!

 

many BMW have a flapper in dual tail pipe at end of muffler operated by manifold vacuum...one could just plug the rubber tube to the valve and the exhaust would go straight thru and was much louder.

 

This sounds like a cheap poor mans way of having a louder, more free flowing exhaust. I don't know about the difficulty of this modifications but I'm excited for someone to do it and see it in action Hahah

 

The muffler on my 05X seems to flow out both pipes at idle. Maybe a tiny bit more on the left, but for sure both sides always flow. They are both the same depth too. 22 inches on both sides, which mean they go right to the back of the muffler.

 

UPDATE

So I cut into the muffler today and found the valve. It's about where I thought it was. The valve is located on the driver's side of the muffler.

Using the die grinder, I cut into the top of the muffler along the leading rear edge approximately 1/4" from the back rolled edge of the canister and then about 2 1/2" inwards on the muffler. The cuts were about 8" long by 2" wide. The muffler canister is doublewalled and most definitely a stainless steel.

The spring on the valve is quite heavy. Far more heavy than I thought it would be. It would take a serious amount of exhaust flow to push the valve open. My guess is around a 10lb spring. I thought it would be a very light spring.

Here's the canister cut open and the valve.


Here's the valve and the passenger side discharge pipe.


Here's a video showing just how stiff the spring is.


Using a sawsall, I cut the valve out.



I then bent the cut canister pieces back down, put some weight and duct tape on the metal to hold it down. I then used JB Weld on the leading edge of the cut to hold cut metal down.



After the bead of weld set up, I removed the tape, and then will run beads of JB Weld along the other cuts.



Hopefully tomorrow I can get this put on. I'm a little nervous because I think it's going to be a bit loud

 

^ A bit loud? you are crazy lol.

Great work dave! I bet you wore the whole suit for the asbestos