Diodes will reduce the voltage and will use some of the ESC power that the motor would have taken.
Can't you program your RC transmitter to limit the maximum power from the ESC by limiting the motor's speed?
i'm know nothing about programming and its a factory programmed..i can't change i guess btw thanks for reply ^^ so if Diodes consume some esc power, does it bad for the ESC? reducing the Amps is all i need