Detonation Sensor

System is used on all California V8 engines. System uses a sensor mounted in intake manifold. Sensor is tuned to frequency characteristic of engine knocking. When knock frequencies are detected, sensor sends a low voltage signal to computer. Computer will then retard timing a maximum of 11°. Amount of retard is directly proportional to strength and frequency of detonation. When detonation stops, timing is advanced to original position.