RPM (range of 0 to 8000 rpms) (may be 8500 on some loggers)

The actual engine rpms the ECU sees from the informantion it gets from the TDC sensor and Cam angle sensor.

It is normal to see some ripples in this curve at higher RPMs. It seems particularly noticeable when letting off the throttle after a WOT run. This seems to be an artifact of either the ECU or the engine sensors. It is not real. This curve shows artificial spikes in the RPM curve just after releasing the throttle (38.5 seconds). It also shows oscillations at the low RPM, just after opening the throttle (31 seconds). I don't know if those are real, but it does seem to be normal.