Frank, check out the 2-1 on the Commando superbike race pic above in this thread, I understand that was based on one of Dr Gordon Blair`s recipes, as for 2-stroke pipes, its not exactly rocket science [but close, & was developed by former Nazi rocket scientist & M.Z. engineer Dr W. Kaaden, based on his V 1 cruise missile mill]. Plenty of harmonic pulse software around these days - the old Hal 9000 et al has no probs with the calculations .
I never liked the sound those 2-1s give, had one to Boyer specs [& likely a Blair design too] on my 500 Daytona, it increased mid-range torque like most collector systems.
However, 2-strokes always work better peak power-wise, with discrete pipes, even when potential harmonic synergies are available, ie in 120`triples, with timing/blow-down event pressure/flow overlaps..
