I already told you, the kv given (by hobbywing or whoever) is based on running the motor on a dyno and seeing how many rpm the motor does. If you change the timing while testing, the kv will change, thus the kv given is an approximation of what the motor will do under one condition. Add in manufacturing tolerances and there is no way to say exactly what the kv is unless you literally run your specific motor with your settings. I don't know how to say this any more plainly.