2 strokes are dumb
Where: Lt = tuned length, in inches
Eo = exhaust-open period, in degrees
Vs = sonic wave speed (use 1700 feet per second)
N = crankshaft speed, in revolutions per minute
Dl = (see text)
D3 = D1 x (0.57 to 0.62, see text)
A1 = (half the diffuser's angle of divergence)
A2 = (half the baffle-cone's angle of convergence)
