2.2 Knock Frequency Setup

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For ease of use, the PLEX KNOCK MONITOR hosts a frequency vs bore size calculator that automatically sets the

knock detection frequency based on the cylinder bore size. In this menu you can choose the center frequency for the

digital knock detection filter.Usually the largest amplitude is found in the primary vibration (or mode 0) frequency.

Selecting your engine's bore size in mode 0 will most of the times provide excellent results.

Required Action

- Adjust the cylinder bore size by clicking the "UP" and "DOWN" buttons


- In some cases the knock signal at the mode 0 frequency could be contaminated due to excessive mechanical engine noise. In

these cases it is recommended to use mode 2 frequency for a better signal to noise ratio.

- The shown cylinder bore size/ frequency relation is given as a guide and should be verified if possible.