gringo
Post missing.
My bike has custom made cans which originally had 50mm outlets. I made new end caps for them so i could play about with some different diameter outlets after an experiment on the dyno which had me holding a peice of wood over the exhausts to half block them. I picked up 2hp over the entire rev range. So i experimented with 31mm, 36mm and 45mm outlet sizes - eventually choosing to use the 36 mm outlets which give me the most power.
Too much exhaust flow on the SD = not enough back pressure = less torque.