Now let me explain what I mean about “my ideas about gas flowing”.
First thing they teach you about gas flowing and dynamic of fluid is “a longer pipe will increase torque and a shorter one will improve power peak”
The second lesson is “a larger pipe will increase power peak and a smaller will improve torque.”
So, what happens with a longer and wider pipe?
That’s the reason I built a sort of “coaxial labyrinth” inside the muffler with three tube of 50, 75 and 100 mm (the last one is the external case of the muffler!) in order to let gas flow trough a path of about 1.5 mt. In my dreams, this sould be the definitive solution to the “exhaust matter”.

I try to draw a schema of the main section of the muffler:
..................._______________
................./.... ____________ \
...outlet__/..../ _____________\_______
............__.....| _____________________ from the engine
...............\ .....\____________ /
................\________________/
is it readable?

This is the time for a road test.
The answer to any smooth handling of the trottle over 2500prm is quick and full (under that I need a bit of “respect” , the sound at idle is regular and at high revs it’s just LOUD! (before I had a 40mm 2-1!). :laugh:

The engine feels powerful even if I’m waiting for a better chance to go for a complete road test.
In the next days I’ll try a carb setting (jets are not so easy to find) and then a severe test by a chief-mechanical of a ducati dealer… I’ll bring you up to date soon!