MSD

I have an MSD streetfire ignition. In the instructions it tells you to hook the heavy red wire directly to the battery, heavy black to ground or negative post. The ignition works fine but the unit draws power with the key in the off position. Question 1, is this normal? checked wiring against instructions several times, positive it’s correct. Question 2, can I wire a relay to shut power off to MSD box when key is off? Any help is appreciated.