It is miles per second, not feet per second.
According to Dr. Hugh Holden [ see link below ] who has done extensive studies on HEI type igns, the ign output
retards at high rpms due to distortion of the flux wave created by the mag pick up. This is really academic because most people either use a timing light or dyno to find the best ign timing for max hp. Either method accounts for any delay
in the spark delivery.
www.worldphaco.net
