Time for another silly question from a newbie. 10 years ago I fitted Y pieces to both my and my wifes BMWR1100S's to eliminate the catalytic converters. The bikes became a little louder, but hardly anything, and had more mid range as a consequence. I know that the 848 has a cat in the front part of each exhaust silencer and I have the mechanical knowledge to remove the cat. I have read loads on the internet from various forums from people who have removed, but all of them have also repacked the cans. Is it necessary to repack the cans due to excess noise after the cat removal or is it just something that people do. Has anyone removed the cats and left the cans as they are, and is there much more noise?
When I did a set I used 3" perf tube as it fitted over the remains of the cat. If I were to do it again I would use a 3" to 2" stainless reducer and some 2" perf tube. I repacked using Acousta-fil. This shows the process Muffler Reconstruction – Part II | That Ducati Guy
Thanks CHris. I was most interested in what would happen if the cat were cut out of the pipe stub and nothing else was done to the can. I'll have another read through that link.
