Muffler replacement question, 2003 M45

[Rex]

Until someone finds a Nissan engineer or the "white paper" on why the valve was there it's all conjecture.

Only valid post here is if you want to change and improve performance (with validated info) get a muffler shop and dyno and lots of time/$$$.

[auditech10]

jamestgk,hey is that your exhaust? if so can you send me more pictures of it, thanks, it looks great and i bet it sounds just as nice. i like the way the stock exhaust sounds so i am very very undecided if i want to change it or not, but i very likely will, lol.

to the rest of the crowd (if this discussion is even open), that valve IS for "performance" sound only. it was the first thing i noticed the first time i put my m45 on the rack at work. the chain drive audi v8s have a very similar valve at the rear muffler that changes the exhaust note a bit. today at work when i changed my oil i stuck the valve open and let it idle and then revved it a few times, i did this a few times both ways and it sounded just a bit louder and nicer with the valve open. just my 2 cents

[Q45tech]

I had an extremely loud cat back exhaust exhaust system for about 6 years [94-2000] until it rusted thru in lots of places. You could roll a ball bearing straight thru from end to end brand new.

I did lots of before during and after when it was totally replaced with a newish oem from a 95 Q.............either way immaterial change in acceleration...........in the stopwatch noise maybe 0.1 second in quarter mile.

The bulk of improvement came from ecu [cone, ecu, and exhaust] changed all in the same month in 94.

The ecu is the only mod still installed.

Save all oem parts if you ever want to try to sell the M45!

[jamestgk]

update... stock silencers were removed they were cut open to reveal straight thru pipe surounded with fiberglass and sound deadening material. two Flowmaster 50 Series Delta Flow Muffler 2.25 O/C were installed. tone was improved without increase in loudness. straight pipe could have been installed but rear muffler will be removed with flowmaster install. this depends on sound without muffler. stay tuned....

[jamestgk]

auditech... did you get my email?

[auditech10]

sure did, looks great so far!