Traditional dyno layout: shaft speed is always positive. Compression is +force (up), rebound is −force (down). Sync the time histories in the step response, load those slopes here as a traditional bilinear baseline, then export a spec PDF for a manufacturer or tuner.
Curve A — front spec
Compression
Rebound
Force vs shaft speed
Compression +
Rebound −
End 0.5 m/s · knee C 0.05 m/s · knee R 0.05 m/s