As always, my curiosity gets the best of me. I planned on doing this for some time now, pretty much since I installed my M perfromance axle back.
It goes back to when I saw a few people modifying the e90/92 M3 exhaust by replacing the perforated tubes, and the result was an amazing sound for very few $$$.
The plan was to replace them on the f30 muffler and reinstall it on my 335i and see what the result would be. But due to chamber 1 and the shape of the pipe this seems pretty much out of the question, as there would be way to much custom work and too much labor involved. Im trying to keep this as simple as possible.
So plan B is to open up the muffler all the way, so that I have access to both top and bottom, and spot weld every single hole individually in chamber 1 and 3.
Ill update as I go.
Video by eyim1988
Video by TurboM