Advanced Techniques for Performance Measurements and Computer Simulation of Racing Ignition Systems

Measurements of racing engine ignition systems using the open spark gap load described in SAE Practice J973 are not repeatable. Commonly used metrics of open gap voltage and ignition energy may lead to inaccurate comparisons between systems in race applications. Measurements made using a pressure chamber load are more repeatable, but the apparatus is expensive and not readily portable. A new ignition load based on a neon tube offers low cost, is portable for field use, and gives very repeatable results. Spark gap current integrated over time is a more consistent metric when comparing the output of various ignition systems. SPICE circuit models have been developed for computer simulation of race ignition systems. Results agree closely with laboratory measurements and provide a convenient basis for comparing system combinations.