Penske Racing Shocks 7300 Series - Manual (Page 23)

Dyno Graph Overview
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4 3
OVAL (Force / Displacement)
QUADRANT #1
This is the beginning of the compression stroke. Where the graph crosses
the zero line (pounds) in quadrant #1 begins the compression stroke.
Approximately the first 1/2" of displacement is formed with relation to the
low speed bleed bypass. When the shaft reaches a certain velocity, the low
speed bleed bypass chokes off and the compression valve stack begins to
react.
QUANDRANT #2
This quadrant begins with the compression valve stack open. Where the
graph crosses the zero line (inches) in quadrant #2 is the maximum force
produced by the compression valving. As the shock approaches the full
compression point, the compression valve stack begins to close as it
approaches the rebound movement.
QUADRANT #3
This quadrant begins with the shock at full compression and the compres-
sion valve stack closed. Where the graph crosses the zero line (pounds) in
quadrant #3 begins the rebound stroke. Approximately the first 1/2" of
displacement is formed with relation to the rebound bleed through the shaft
and jet. When the shaft reaches a certain velocity, the bleed chokes off and
the rebound valve stack begins to react.
QUADRANT #4
This quadrant begins with the rebound valve stack open. Where the graph
crosses the zero line (inches) in quadrant #4 is the maximum force
produced by the rebound valving. As the shock approaches the full
extension point, the rebound valve stack begins to close as it approaches
the compression movement. At this point the cycle starts over again in
quadrant #1.
Force / Velocity Average
This graph shows the averages of the
accelerating and decelerating compres-
sion and rebound forces. It is a good
quick, general review of the shock
curve, but is the least accurate of the
options displayed.
Force / Velocity
This graph displays the accelerating and decelerating
compression and rebound forces. Think of this graph as the
Force / Displacement graph (below) folded in half.
* Hysteresis is the gap between accelerating and decelerat-
ing compression and rebound damping. It is affected by the
type of piston, the shims used and the relative position of
high and low speed adjusters. The bleed hole will close the
gap or soften the low speed forces.
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1
3
4
Hysteresis
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