Influence of a Breakdown Ignition System on Performance and Emission Characteristics

The performance of an experimental breakdown ignition (VFZ) system has been compared to a conventional transistorized coil ignition (TCI) system using a production four-cylinder engine with a compression ratio of 9:1 and a swept volume of 2.3 1. Spark ignition energy and electrode spacing were identical for both ignition systems. Results at quarter load, idling and overrun demonstrate that for optimal engine efficiency considerably less spark advance is necessary when the VFZ-system was employed since the initial combustion period is reduced substantially. This enhancement in initial flame development provides a wider range of optimization, when changing spark advance and air-fuel ratio. Therefore significant improvement are possible when focusing either on reductions of fuel consumption or pollutant emissions.