Silencer - Toyota Sprinter Trueno, 1.6 liter, 1985

And in more detail?) From what, how, what sizes, how was the calculation made? ... it’s worth just now the task of making

What about pipe length? What is the muffler outlet diameter?
By trial and error, I came to an inner tube of 40 * 250 with an inner diameter of a can of 98. At the same time, the frequency response became more or less uniform in the range of 2200-4500 rpm.

40mm tube, inner, scrap cup