220: Three Scales

There are three scales.
The one on the right (navy shirt) indicates a 10 N force to the right ... +10 N.
The one on the left (green shirt) indicates a 10 N force to the left ... -10 N.
What will the scale in the middle read?

Thanks to @fnoschese for posting this.

53: Right six, CARE, tightens, gnarl. Jiggy Jiggy, Fifty, crest. Right three minus

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The 7.6-mile-long Mt. Washington Road is lined with trees, drop-offs, and winds on the way to the 6,288-foot summit. Travis Pastrana in a 2011 Subaru Impreza WRX STI rally car, with an officially timed run of 6 minutes 20.47 seconds.

There are questions all over the place.

1. Average speed
2. Average slope of the road.
3. What do the calls mean?
4. Add more in the comments. 

This one includes rally notes system details. "Increases the radius, decreases the radius" "Can you take it wide open?" "If the notes are wrong, we go off a cliff."