Quote:
Originally Posted by JANNETTYRACING
It varies by engine rpm and load and each cylinder is different.
Take thousands of hours of dyno testing at GM to build the Knock Threshold maps for each cylinder and each engine type.
The sensor is a simple microphone, what they must weed through is what each frequency generated means in terms of real or false knock at each load cell and rpm for each cylinder.
Ted.
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Fantastic... I sort of stumbled upon this conclusion myself when I saw a device for sale that would act as a standalone KR controller. It had what looked like an exponential curve for knock threshold... I don't know if that was amplitude or frequency or both.
PITA because I need a means of arresting my power adders if the car experiences knock but I can't access knock information in the ECU directly so I have to re-invent the wheel using my own electronics. So far my research has led me to believe that 5.6 kHz is a nice center frequency for the LS3 so I have designed a bandpass filter to block out everything +/- 500 Hz away from that. Then using a Fourier transform I can monitor the levels in that range. I'm sure it will pick up knock. The question is, how much will the calibration vary with RPM and load...