If I understand it correctly, the 5th gen muffler has a spring loaded valve that opens a second passage in the muffler when the exhaust pressure gets to a certain level. This allows for a quiet car when under say 3500 rpm, but will open up as a more "free-flowing" exhaust at higher RPMs or WOT.

Is it possible that if you switch to a y-pipe and perhaps even add the b-pipe on a 4th gen maxima and then use the 5th gen muffler that the back pressure would not be sufficient to open the spring valve thus never opening the second passage in the muffler?

Does anyone have experience to show that the exhaust note and decible level changes on the 5th gen maximas when under WOT or high RPM? Is there experience out there to show that the 5th gen muffler "opens" at different RPM levels depending on what other exhaust modifications you've done? Any head to head comparisons between a 4th gen and a 5th gen? Does the spring valve appear to open at different times depending on setup?

Thanks for any information you can provide.

- Jeff

 

Just get an aftermarket muffler ,they look better and give better performance , you can get one for cheaper than the 5th gen muffler and there are so many diffrent kinds to chose from.

 

Some people dont really want to be louder though, and would rather have a quiter car for lack of a couple HP.

 

Your theory is flawed. Backpressure is not what opens the valves in the muffler. Exhaust pressure/velocity is what opens the valve. Adding aftermarket parts like a y-pipe increases exhaust output and would probably cause the valve to open earlier.

 

I suppose that the restrictive OEM y-pipe would cause a drastic pressure drop downstream of the pipe. The high-performance y-pipe would not have this pressure drop thus having more "volume/pressure" when it hits the spring valve. Interesting thought.

My goal is to have a free-flow exhaust when I want it (WOT), yet be quiet while cruising on the free-way. In theory the 5th gen muffler should do this. I just hate to make the expense if it won't do anything.

 

5th gen muffler should meet your compromise. I run one..

 

Bah.


Up with 5th gen and blend of quietness, oem look, and slight performance gain.

 

i had a y-pipe, custom b-pipe and 2k1 muffler. the 2k1 muffler is considerably low in sound at low rpm's, just has a small himmmm to it. It doesnt get much louder at higher rpm's but once again its stock so u cant expect much sound out of it. as far as gains, i think a aftermarket exhaust would give u more but i definitely felt less restriction compared to stock 4th gen muffler and still much more quiet than aftermarket...

i also have one for sale BTW

 

I have all those mods and the flap opens at just below 2500rpm. Last time the car was up for exhaust work we could actually hear the click of the flap closing when the driver let off the throttle. Only a slight difference in sound as far as noise and note.

Next dyno will compare RT Cat vs hollowed out OEM Cat.

 

Really? I thought it opened up way higher than that. I was thinking more like 5000rpm. I'm very surprised. Can anyone else confirm this?

 

mecca, bess' check yo PM. Seems like every time I ask ppl about 5th gen mufflers, eventually I stop getting responses.

 

Here's the official release from nissannews.com Somewhere there's a short video showing it too - used to be under Nissan technical inovations & stuff.

"The adoption of a new variable capacity muffler system improves both engine horsepower at middle and high speeds by reducing exhaust pressure and reducing exhaust noise at low speeds. The system uses a valve which opens and closes according to exhaust pressure inside the muffler, switching the flow of exhaust gases from one tailpipe to two.

At low exhaust pressure, for example, while idling or coasting, the control valve remains closed. Exhaust is emitted without passing through a secondary bypass, through a single exhaust pipe. As the pressure becomes higher, the control valve (using aerospace industry spring and composite technology) opens, and the exhaust gas flows through a bypass – reducing exhaust resistance and exiting through the car's dual exhaust pipes. The valve opens in the 2,000 – 2,400 rpm range and is always open at wide-open throttle."

 

Well, there you have it. It sounds like it opens early based on peoples' real world experience, doesn't raise the noise level too much, and is backed by Nissan's technical notes. This confirms, at least in my eyes, that the Y-Pipe, B-Pipe, and 5th Gen muffler is a great setup for those of us who want quiet performance.

Thanks for the responses. This forum is wonderful.

 

There we have it. =) Funny because when I first installed the muffler. I floored it from the muffler place. I could have swore there was a boost after 5000 rpm. Maybe it was the butt dyno.

 

Add an MEVI and you have pretty much just put a 5th gen 3.0 motor in your 4th gen.

DW

 

Sorry for being naive, but what is MEVI?

 

http://forums.maxima.org/showthread....53#post1743653

scroll up, you'll find the answer..