Here are the setting for micron cobra motors.
M92 E1600; Set steps per mm for 16x microstepping
M566 E120; Set maximum instantaneous speed changes (mm/min)
M203 E1200; Set maximum speeds (mm/min)
M201 E600; Set accelerations (mm/s^2)
M906 E800 I30; Set motor currents (mA) and motor idle factor in per cent