To improve available power, tolerance to variation in fuel octane number and high engine speed knock control, an individual cylinder knock control has been developed.
Knock are detected by spark plug washer transducers. Which indicate individual cylinder pressures.
Last year we read a paper entitled “Cylinder Pressure Vibration Analysis Indicates Accurate Knock Detection”. We read continuously on the following items.
Spark plug washer transducers - These are piezoelectric ceramic rings which fit beneath individual spark plugs. These can detect knock at high engine speed, and are very durable.
Knock detection and control algorithm - Knock is indicated by the transducer's cylinder pressure vibration signal. When knock occurs in the cylinder, the ignition timing of the cylinder is controlled. During the transient condition, control response is fast by learning control.
Fail safe - At transducer trouble, the ignition timing of the cylinder is controlled by other transducer signals.
Electric control unit - It is included in NISSAN's Electronic Concentrated Engine Control System (ECCS).
Effects of this control - It improved WOT torque by 7-15%. torelance to variation in fuel octane number, and high engine speed control performance.