Hey everyone...
There are tons of posts in regards to which mufflers sound the best on our 6th and 7th gen Monte's. Most of the time someone wants to make it louder, deeper, boomier... whatever. I want to go the other direction. I've had plenty of loud vehicles with Flowmasters and Black Widows on them, but blasting my music to make a soup of loud guitar, high notes, and a loud, droning engine are in my days past.

What is the QUIETEST muffler I can possibly get for my 2006 3.9 LT? I have a dual muff system now, and it's not very loud to begin with. It has a nice rumble when you're next to the car, but when the time comes to replace some of the undercarriage parts that are getting rusty, I want my car to be an unnoticed whisper when I drive by.... unless I'm blasting Rush. In which case, I'd rather my engine not muddy it up.

Any ideas?

 

I don't think you'll get quieter than a stock muffler- why not just run them?

 

Why do some go to a louder muffler? It seems to be a matter of preference. I simply want to go the other direction and make it quieter. It's not that quiet as it sits. Like I said, it has a nice rumble to it. I've seen cars with much bigger engines that are much more quiet. Especially old luxrury cars like Cadillac, Lincoln, etc.

 

I think I didn't say it well enough - I'm not questioning what you're trying to do - I'm assuming you've got aftermarket mufflers (as the stock ones should be pretty quiet) on there and asking why you wouldn't go back to stock? If they are stock mufflers, are you sure they aren't rusted out? (No offense intended, but these cars are pretty old so I have to ask)

If you're trying to go even quieter than that, I'd start by looking at stock exhaust from a similar year Impala. Ive had 3 Impalas from 00-08 and they were all whisper quiet on the stock exhaust. Theyre also the same chassis as the monte, so it should be easy to fit them. Another option when junkyard hunting, you could also take a look at other stock vehicles with an exhaust sound volume youre trying to replicate that have roughly the same sized engine (ideally something like a Buick Park Ave, Lesabre etc with the 3800 - those things are practically silent out of the exhaust).

If thats not enough, you'll have to go more extreme:
-if the tips are anything other than the same size as the exhaust pipe (ie larger, trumpet shaped tips), cut them off and replace with regular 2.25/2.5" pipe
-depending which resonator you have, you might have more space in the tunnel to add a bullet muffler by shifting the resonator forward and adding a small bullet muffler behind.
-another more extreme option would be to ditch the dual exhaust and use that space for running 2 mufflers in series instead of parallel. I.E. delete the Y pipe, run the exhaust into one muffler, then have it snake around (under the car) back over to the other muffler. You could put a fake tip on the first muffler side so it still looked like you had dual exhaust from the back if you cared about that.

 

I get what you are saying now.... No, I think they're stock. They seem a lot louder at six in the morning than they usually do, but they do have some growl to them. There's a little bit rust on the outside of them, but they don't seem to necessarily need replacement yet. I'm not going to make a change like that just for a little reduction in sound. It's just an idea when it's needed.
Thank you for the iinput!

 

Replacement stock mufflers if you want it quiet... If you want aftermarket mufflers, just put a long skinny exhaust tip on it, it'll quiet right down.

 

The loud sound might not be the mufflers. In line with Bumpin's thoughts, I would inspect the exhaust you have. Make sure no holes or damage. Change matting surfaces, make sure nuts/bolts are tight and that gaskets are not worn out from years of age. Inspect the flex joint on the downpipe. If you find any leaks, see if you can fix those and then decide next steps.