That is my point that although a few runs had virtually no knock, there were several runs which hit timing targets roughly 33-34 around 7500 plus RPMS, IATs were ice cold and a cold night and 100 octane in the tank. All of the possible controllable factors yet knock still showed up. Clearly since timing was still close to the targets with a tune (although I don't know the exact targets with this tune) I figure the knock was very subtle. It also was only for the 7500-8k range and than 8k-8500 had no knock, which also seemed strange until I realized maybe the VE above 8k is better and perhaps that has something to do with less knock.
Very complex engines indeed!
By the way AFR's were spot on. So my point is if knock still happens in these ideal conditions, I hate to see what kind of knock is actually going on in the dead of summer on 91 octane. Almost scares me! Sometimes too much information is not a good thing!