Calculating the exhausts with Pipe designer.
http://ypvsbox.free.fr/software/PipeDesignerDemoEngSetup.exe
After cutting the cones out of paper (using the programme cone) I'll draw them on a 0,7mm steel plate
With a little bit of fixing I can get two pipes from one plate
Cutting them rough out of the steal
Then more pricies
Bend the cones and weld them together
And start welding the pipe
Until you have two sets ready
Mounted on the track bike 1