The interesting thing about this topic of getting more speed out of an electric golf cart is that once all of the available energy from the batteries is applied to the motor, it’s all up to the motor to determine the speed (without changing gear the ratio). In my book, I constantly refer to this point as the 100% duty cycle point. It’s like once you have applied full battery supply voltage and current to the motor, there “ain’t” no more available. Whether the 100% is made available through a motor speed controller or a series resistor string (with solenoid switching of contact switching) it doesn’t matter. 100% is 100%. At that point it’s like you took a toggle switch and applied B- to B+ right across the motor and you don’t get any more. So, you best think “MOTOR” to change things speed wise. Now granted, if you aren’t at 100% because of a weak or defective motor speed controller or some other problem that prevents 100%, then that must be remedied, but putting a bigger speed controller in or anything else that doesn’t contribute to the duty cycle won’t help. You can put heavier wires on the batteries, F/R switch and motor connections and you will get closer to 100%, but that is about it without some major modifications.