As the above link points out: Shut off the engine at the end of a drag strip run, after a full throttle blast at high load and high rpm. Then tow the car back to the pitts to read the plugs. That would eliminate the problem with the Multiple Spark Discharge changing the plug coloring.
That would sure be tough to do with a typical Cobra though. How are you going to tow it, or get it back to the pitts after a 1/4 mile run?
