I tuned the ignition of my turbo cb750 with an ignitech module with MAP sensor (and GPZ stator+rotor), and just followed the torque curve of the dyno a bit. After peak torque I gradually increased another 2-3 degrees.
And the whole thing is boost retarded from 0-7 degrees at 0 to 15psi.
Works nicely and is also not expensive.
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