My settings with S77 this year - dry threshing conditions - 20 bus (residual chem issues)-50+ bus, 30'swaths
Top Sieve - 3/4"
Bottom - 1/2"
Concave - .4 indicated with .1 clearance at 0
Wind - 4.4 - 4.7 indicated when machine is operating
Cyl - 440 - 470
Sample was really clean except when it did get really dry
And I do get some rumbling (from slow rotor I believe) if I tried to push to hard
I would be really interested if you tried that rotor speed (650) and clearance (1.0) what you found
I should also note, I had narrow wire concaves in this year and I do believe my shoe load was less compared to last year.