the resistor coils on a electric cart do they control any of the speed or power of the motor or are they just cooling coils i have a set up a friend of mine made to replace the coils it is made out of quarter inch aluminum plates spaced out and insulated just like the coils would it be worth changing to these or would it burn up the motor or cause any other type of damage he said it changed the speed of his and kept the motor cooler dont want to try it if it will damage my cart