Originally Posted by NoTempoLimitN54
The only way to definitively answer the question about the construction of the BMW Performance exhaust without cutting one open is to have one x-ray'ed.
Are there not large x-ray machines used to inspect aircraft parts for metal fatigue that could work for this.
Yesterday a 335is drive past me while I was waiting to make a left turn (and he's turning left from 90º to my right. He was accelerating quickly so I got a good chance to hear the is exhaust. Then I drove off and heard my own exhaust (stock 335) for comparison.
It seems to me that the sound of the is exhaust had a similar character to stock, except that it was louder and had more of the higher pitched noise.
So maybe it is the same design with less packing...?
My neighbor has a 335is with catless DPs and it sounds awesome. I haven't heard a 335i with the PE exhaust yet, so I can't compare, but is hard to imagine it can sound better than the 335is exhaust