What is false knock?

 

Thanks FLTRI17 I'm more than happy sticking with the oem, I've got a dealer on my door step. I was just curious why the characteristics of the 6r12 seem to have changed with the 6r12* with a dot

False knock is when the Ion signal detected is outside the range/characteristics the ECU is programmed to detect, but is not a real knock event in the cylinder.

http://bmwmotorcycletech.info/ioniza...-susbystem.pdf

and an interesting snippet from last year
https://hdbitchin.com/index.php?topic=2712.0

ok that Delphi solution isn't necessarily the one used in HD but i'd expect the basis to be essentially the same. If you look at the diagram the Ion signal is essentially how quickly the lead/plug/ion-gap reduces the 80 volt charge (edit: ) set by the zener (D2) threshold.

With known lead/plug - the ecu measures the ion-gap - change the plugs or faulty leads etc, the ecu may think there is a knock when there isn't (or vice versa)

 

My understanding:
False knock is when the system erroneously determines a poor combustion has occurred which triggers an ignition retard anywhere from 2 to 8 degs (most Delphi until recently) for a time period then return to base settings.
False knock can be repeatable or come and go sometimes tied to heat and/or load, sometimes not.
False knock's a bitch with big, high compression builds. Some turn EITMS off to eliminate false knock. But then the owner needs to be more alert to knock (detonation) that can come with high temperatures and fuel quality variations.
I have found plug gap influences false knock.
I have found plug wires, sometimes stock, can cause false knock.
I have even found stock spark plugs can cause false knock.
Bob

 

Well that's just a bunch of good news