Inside a Bosal muffler (with pictures)

Short and sweet. Replaced the rusty stock muffler with some tiny trashcan a welder sold me on. It droned so bad it had to go. Got this Bosal from Summit Racing, straight bolt-on. Two months or so in it started to rattle (not to mention leaked and the flange that affixed its pipe to the cat's bent before 20ft.lbs.)
I now have a Walker SS Quietflow, and I cut up the Bosal to see what it's deal is.






In this pic ^ you can see that the sectional dividers are crammed into place and only welded to the pipes. Unsure if that's standard for assembly, but it's the only thing I could identify as a potential noise maker.

 

That's fascinating and disappointing. Thanks for cutting it open and exposing the guts. Bosal wont see a cent from me.

 

i experienced the same thing, bought the bosal cause it was $10 cheaper and it was a whole assembly from the flange where as the walker was a 2 piece that had to be clamped or welded. after about 2 and a half to 3 months later it had a terrible drone and sounded like shit i tried to warranty but bosal customer service gave some extremely terrible customer service so i ordered the walker online welded it up and haven't had any issues for about a year now. Walker is definitely the best oe replacement.

 

Want it to last use high heat black and give the whole system a coat or 2 works wonders stopping rust and looks better as harder to see!

 

@luka4600 I wasn't sure if my experience was unique to me and appreciate the info! One of the big draws to the bosal for me was, as you mentioned, it's already piped and ready to go. Another was the method of bending. I figured the way walker kinks the pipe to bend it looked shoddy by comparison (just uneducated speculation,) but my opinion is revised. I'm super happy with it. The only negative mark I'd offer is that hangers and the tail pipe, to name a few spots, have some surface rust on them already. I may take it off and paint it later. Regardless, Walker is a breath of fresh air after my experiences.

@muddog321 I'm thinking I'll do just that.

 

Pyts you can paint it when mounted - I did. Not that hard to reach from mid-pipe all the way to tailpipe.
I didn't like the tailpipe either but no impact on performance and once painted that stopped the rust on the seams.

 

you can definitely paint it if you want but that will void walkers warranty thats one of the reasons bosal wouldnt help me because apparently paint causes a exhaust system to become damaged

 

@luka4600 Ah, they must be figuring that the paint increases heat retention. I've read personal accounts about that with exhaust wraps used on motorcycles, that they over time make the pipe brittle because it can't shed heat as well, resulting in high temperatures beyond what the metal at its thickness could handle. Though I haven't heard complaints of the like in regards to painting exhaust components, I have been informed that one shouldn't paint cooling fins on an air-cooled engine for the same purpose.

With that in mind I'm glad that I didn't paint yet. I still may, as I don't usually deal with warranties, but thanks to your input if I should elect to paint the line I would avoid painting the muffler itself (as I imagine that since it has the most flow resistance, and its shell less thickness, it would be more sensitive to heat) and just get the hangers and pipe.

You know, one of the biggest factors in my not painting before install was that I'd wanted to do the catalytic converter also, but I didn't want to drill the rivets out of the clamshells and dig up new hardware to re-affix them.
I'm really appreciative of your input!

@muddog321 Agreed! It wouldn't be necessary to uninstall stuff before painting. I however enjoy pulling parts off of cars and hate doing paint prep Foregoing prep, no one would see the over-spray unless I took it to a shop for services, but I kinda enjoy having an outlet for my obsessiveness, as demonstrated by my long-winded replies.

 

Reminds me of the first welding job I had out of high school. The job shop I worked at would get these contracts from a supplier of large mufflers for train locomotives. We'd fabricate and weld up the mufflers for the supplier then about a month after we made them the supplier sent them back and we'd cut them up. The purpose was to see how the exhaust gases flowed through the muffler. We never had a contract for production, just the one-time make, and cut-up.