Knock Frequency Calculation – KSC 3 Setup
2 min read
This video demonstrates the “Knock ID” tool in the KSC 3 Android app. The Knock ID tool executes an engine knock frequency calculation. This is the first step is setting up the KSC3 to detect engine knock.
Knock Sensor Controller Setup
To setup the KSC3 to detect engine knock, first the knock frequency as received by the KSC3 needs to be identified. Secondly, the normal volume from the knock sensor at this frequency (frequency window) needs to be identified.
When we have identified the knock frequency and the normal volume of this frequency when the engine is not knocking, when we have these two numbers, we can detect engine knock.
The Process – Finding Knock Frequency
1-Ensure engine in a state where it will NOT knock between 2-3K RPM at light throttle
2-Switch “Knock ID” ON and drive from 2 to 3K RPM at light throttle, press off before lifting throttle.
3-Repeat process a minimum of three times. If values are very different between runs check wiring, check engine is not knocking, make sure throttle is consistent between runs.
4-Advance ignition timing so engine will knock, in a non-damaging way, at light throttle, between 2 and 3K RPM.
5-Repeat step 2
6-Compare each set of runs to see at which frequency, knock is being detected
7-Set low knock frequency and high knock frequency. Add some margin above and below eg 500Hz
Question?