In a prior thread
I described my need to match two cars that have different speed controllers. One is a HobbyKing variable-timing (but no "blinky" no-timing setting) ESC with fixed endbell motor. The other is a HobbyWing Justock (no-timing) ESC with an adjustable endbell motor.
This is how I matched them.
I took an F1 car with brushed motor, turned it over and hooked the motor leads to a voltmeter.