Highly Scientific Muffler Test

[Docmallory]

Replaced my muffler with a Borla cat-back a few weeks ago. The old exhaust has been sitting in the bushes since then, waiting for the time when I could take a closer look at it.

I had been plagued by the infamous whistle on acceleration with the old exhaust (no longer present with the Borla).

Tonight, using my trusty Shop-Vac, I blew air into the pipes of the muffler and the resonator. With the resonator, no whistle. With the muffler, a very loud, distinct whistle was heard.

So, strong evidence that the infamous exhaust whistle is truly from the muffler. Over the next few days (if I get time) I hope to track down what has happened inside the muffler to cause this whistle. -Any suggestions on how to go about this?- My first step will likely be to remove the pipes from either side of the muffler to eliminate those as the cause (especially the 02 sensor flange).

Curiously, with my preliminary probing of the muffler, I was surprised to find that the muffler body is not just a metal case, but a metal case wrapped in (fiberglass?) batting, then wrapped in another metal casing. Never knew that...

 

[Junk]

Yup, sounds highly scientific

 

[cruiserdan]

Junk wants to be our ambassador to the UN............Opinions?

 

[97cruiser]

UN ? Oh ya, United Not.... or something along those lines.

 

[Klunky Chris]

ummm........

I could've told you it isn't from the resonator....

I've been driving without the resonator since one of my first snow wheeling trips long ago and still have a very distinct whissle

How loud is the Borla??

 

[NY cruiser]

how much was the borla???

Also how does it sound i am very interested in getting one myself, do you love the sound? Post pics if you can please



Also do you have any air leaks around the cat??? I am having a big problem with this now, dont know what to do about it. I bought all new gaskets and everything. Mechanic says flanges are out of shape due to age. who knows

 

[Safado]

Just a guess here, but what you may find is something like what they're selling in this video.

http://media.ebaumsworld.com/index.php?e=bubbrubb.wmv

doesn't seem impossible for something like this to happen naturally as thing corrode inside the muffler.

 

[Docmallory]

Chris - Yeah, I always figured it wasn't the resonator.... But then there's the cats and everyting else. Plus, it's just a confirmation that it IS the muffler.

I'll be honest. I'm not super crazy about the Borla. Not because of fitment issues (see other thread), but because it is not the sound I wanted. Others here have warned that an I-6 will never sound "good", but I thought it would at least sound better than it does. Sound is subjective, but I think it's too flat a noise - quite deep, but more buzz than rumble. Perhaps this is not the fault of the Borla, and owing more to the inline design of the engine. Either way, it's not annoying or anything, and it sounds better than the whistle I had before... just not exactly like I had hoped.

How loud is it? I dunno - loud enough that when the windows are up, it can be heard easily, but not intrusive. When the windows are down, it is loud enough to hear over the radio at low to medium volumes. With the rear hatch open, it will boom inside the cabin.

Safado - I would agree - I think there must be something inside the muffler that is deteriorating, deforming, and causing the whistle. I guess in the end it will all be academic, since there is likely no easy fix - but I just wanna know what it is.