Exhaust butterfly valve is mainly used to silence or reduce noise emitted from the exhaust and they also help to smooth out pressure waves from the engine as well at various RPM’s. These valves are commonly used within the automotive industry, and they will be found working in all modern cars or...
I have to disagree here It is not an attitude, I love tinkering with things just like everyone else but i wont be messing about with things that BMW spend millions in the development of for their motorcycles and cars. They are there for a reason, torque curves, noise control etc. and are beyond...
I used a endoscope with a 600mm extension and took snap shots every few inches, picture of equipment below. I also took a video but it is to large to post unless i can figure a way to compress it.
Plan for the winter is to cut a section underneath on the backside of the exhaust at entry to the Fishtail and at the first bracket. Then use a S/ST s-bend similar to the picture to smooth out the flow from the butter fly valve to the fishtail and make a new solid baffle with a hole in the...
Took some pictures of the exhaust internals from the butterfly back, you can see some poor welding and overspill possibly restricting flow. only one baffle in there and the rest of the sound proofing is in the massive cavity of the fishtail itself.