The fact remains that it is up to the race directors to call the cheaters... not all clubs enforce tight rules, i.e. weight, body style, height, wing size.... in fact, there are far too many rules for a one man show to run each car through before and after the mains, quals, etc.
In some cases, yes the racer can call for a motor to be tech'd.... but the person doing the tech would have to know what they are doing! This is usually where the rules fall short - in the hands of the tech.
Wilde