Knock (global vs per cyl)

[The Notch]

Working on a gt350 and saw that the previous tuner had knock set to per cylinder, i relized this because their has been no knock sensor activity at all, when i turn it to global now its picking up knock(which i do believe is false) but curious as to the function of the setings

[murfie]

If its set to global all knock events show up as "knock Retard" in the scanner. If its set as Per cylinder you need to log "knock cyl #" for all appropriate cylinders. I am not sure if it came from factory as global if you can just change the switch and have it tell you which cylinder the knock is coming from. I think the most of the ecoboost come as per cylinder from the factory. I will have to try it out and see.

Basically the ECU knows which cylinder just fired and associates it with the knock event. From that you can either try to correct it in the cylinder offset spark table rather than just pull timing from all cylinders or even the fuel imbalance if it looks like the knock could be associated with it. Its just a way to make sure you are getting the most from each cylinder and not the weakest cylinder.

[HPF]

didn't find knock cyl on scanner to know which cylinder knocking its cool thing if i know which cylinder