B&B muffler - odd sounding

[joseph222]

My 89 carrera has a stainless steel B&B muffler (from PO), that was really nice sounding until recently. It sounded so good it was all but impossible to roll the windows up.

However, it has started producing an irritating vibrating buzz between 2-4k rpm.

Almost sounds like an exhaust leak, but we've determined it to be a vibration inside the muffler itself. Like part of something has broken partially loose. Applying pressure with a stick against the body of the muffler, we can make the sound come and go.

Anyone have experience with a similar situation and tried a repair?

Any procedural tips or precautions appreciated.

Seems like perforated baffles are usually attached to the end pieces.

We were thinking of cutting that open to start with.

Comments? Observations? Suggestions?

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[haycait911]

I fixed a similar problem once by drilling a hole and then threading in a long screw. stopped the noise.

[joseph222]

Thanks haycait911 - Did you drill the hole into the side of the muffler body, or into the passenger side end piece?


Anyone else with suggestions/experience?


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[fireant911]

I too had a very annoying noise from my B&B muffler that occurred within a certain rpm range. I loosened one of the muffler clamps and placed a strip of thermal cloth to stop these vibrations. I am NOT an advocate of B&B exhaust systems - I have since sold the complete system (heat exchangers and muffler) and replaced it with the stock exhaust and absolutely love it (as do my neighbors).

[haycait911]

I drilled right where the noise was coming from. maybe I got lucky, but probably worth a try before cutting into things. if it works, you could overweld the screw head to prevent loosening. Don.

[Jgordon]

B&B had some issues with earlier mufflers with cracking, both internally and externally. You can see the extra bracing they welded on later models. Chances are that an internal baffle broke loose and is lightly vibrating against the muffler wall in that rpm range (typically a harsh point in the B&B range). I'm actually surprised you liked the sound prior to this, I had a system and couldn't take it, as has been the experience of a number of people on the board.

It depends on your preferred level of involvement as to how you fix it. You could try pressure at different points on the muffler body, and drill/tap a screw at the point where you find the best improvement from touching. Seems like a scattershot approach though. You could also ask B&B for a schematic of the muffler, and for their advice on how to go about it. At the least, you'd know the layout of the internals and could gauge where the break likely occurred.

[Trog]

I've had the B&B 2 into 1 system for 8-months now and am absolutely satisfied. The sound is 'just' right and the system has performed flawlessly.

[mb911]

Originally Posted by Jgordon

B&B had some issues with earlier mufflers with cracking, both internally and externally. You can see the extra bracing they welded on later models. Chances are that an internal baffle broke loose and is lightly vibrating against the muffler wall in that rpm range (typically a harsh point in the B&B range). I'm actually surprised you liked the sound prior to this, I had a system and couldn't take it, as has been the experience of a number of people on the board.

It depends on your preferred level of involvement as to how you fix it. You could try pressure at different points on the muffler body, and drill/tap a screw at the point where you find the best improvement from touching. Seems like a scattershot approach though. You could also ask B&B for a schematic of the muffler, and for their advice on how to go about it. At the least, you'd know the layout of the internals and could gauge where the break likely occurred.

what do you think of your new gen5? sorry guys for not bringing anything to the table

[Jgordon]

Unbelievable. Perfect. I still have to post a thread about it. Roadtrip to PA this weekend and I'm hoping the sun comes out so I can roll the windows down and listen to it.

[cgarr]

I had a repaired B&B muffler then went with the much lighter M&K That B&B was like an anchor right where you don't want it!

[joseph222]

Don - That's a good idea. Thanks again

Following Jgordon's suggestion, I talked to B&B today and they were helpful (although they don't release schematics). All of the internals are attached to the passenger side end piece. If we have no satisfaction with the screws, we'll open up the end piece and go from there.

Cgarr - how much weight difference do you think there is between M&K and B&B? I own both. I'll weigh them.

As far as the sound goes - mellow & powerful - I absolutely love it. Deep rumble at idle, a refined and muffled purr at mid-range with a nice bite at the upper end.

I've ran Bursch, Triad, SuperTrapp, and M&K. They each have their signature sound. But I've never had as many positive comments to the exhaust note as with the B&B's.

We can't all have the same opinion now can we?

Thanks to all for your help. I'll let you know what transpires.

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[84CarreraSC]

Mine came with the B & B muffler and I think it sounds pretty good.

[Jgordon]

Glad to hear it's working out. I have a number of changes in my engine - p&cs, cam, chip, etc so we're not even hearing the same note.

Interesting though that they're all attached at one end. Might be worth cutting a few patches and reaching in to tack it to the muffler body, that might help stop the noise. Likely you'll find the source though when you pop the end.