So the dip is supposed to be knock then? Come on guys that could be any number of things (tach signal loose, gummy injectors, etc.). You want to measure knock get the proper equipment on a load bearing dyno at varying engine speeds.
In a knock event where timing is pulled you will see some indication on the A/F curve(abruptness) and it looks pretty smooth on the Z1 graph.
I'm not saying that its not possible I'm just saying that these types of statements can get taken too far on very little evidence.
Side Note: Much respect to Berk for there excellent testpipes on the S2000.
