With gas engines the total horsepower is maximized by more RPM, if the F1 engine was not limited we could have 25.000 rpm engines today as the last non limited engine could reach up to 21.000. With that you need to determine the right gearing. More RPM can be used with a higher FDR that does compensate the loss of torque at the motor to a raised torque at the wheels.

To come to a conclusion which timing works best you need to have a test bench where you can change the gearing to a wished number of topspeed rpm and then measure the torque curve on the geared shaft.