Not all detonation is initiated by over advance or excessive boost. Excessively high charge temps., hot spot within the chamber etc and it needn't be pre-ignition either, detonation can occur after the spark. I've actually experienced high values on the KS3 on closing the throttle for gear change, typically 4th to 5th after pulling quite hard. It was explained to me as 'transitional' det. I'm sure one of the respected mappers on here could explain the term? (I daren't attempt an explanation as it was some time ago when it was explained, although I recall understanding it at the time!)

JohnD