MoTeC Knock OKM - Manual (Page 8)

8 Configuration
The knock module filters and amplifies the signal transmitted from the knock
sensor based on the centre frequency. Signals of the selected centre
frequency pass the frequency filter
amplified, while signals in other
frequencies will be reduced. The
further away from the centre
frequency, the more the signal will
be reduced. Filtering will reduce the
influence of background engine
noise resulting in improved knock
detection.
The figure shows frequency based
amplification with the centre
frequency set to 12 kHz.
Frequency based amplification
Gain Factor
A gain factor is only required for knock sensors with very low output levels.
The gain factor can be chosen to multiply the raw knock output signal, prior to
frequency filtering. It is also possible to set a gain factor from ECU Manager
software.
Knock Module Configuration
The configuration of the Knock Modules consists of two stages:
Stage 1: Carrying out a frequency analysis of the knock sensor signal to
determine the centre frequency and knock module settings. This needs to be
done by a competent tuner, as incorrect operation can easily result in severe
engine damage
Stage 2: Tuning the knock control system
Note:
The OKM settings are preconfigured to suit the standard vehicle. It only
requires the second configuration stage to tune the knock system. If the
vehicle is modified significantly, contact an authorised MoTeC dealer for
further advice.
Before carrying out any stage of the configuration the vehicle needs to be
prepared by setting up the ECU for knock measuring and data logging using
ECU Manager software.