Penske Racing Shocks 8900 Series - Manual (Page 7)

8987 Series Compression Adjuster
NITROGEN
OIL
HIGH SPEED COMPRESSION ADJUSTER
HIGH SPEED COMPRESSION ADJUSTMENT
In fast shaft movement (i.e. bumps, track
inconsistencies, etc.), oil is displaced into the
reservoir, as in the low speed state, but at a
much faster velocity. The oil is forced to bypass
the low speed needle and jet due to the fact that
the small orifice in the jet causes the oil to
hydraulic. In turn, the oil is forced through
another piston in which it’s orifices are covered
by another shim stack. This shim stack is
preloaded with force from the CD cage and
preload shims. By turning the high speed
adjuster clockwise (stiffer), you are preloading
the CD cage and shims, making it tougher for the
oil to flex the shims.
The operation of the high speed adjuster
assembly effect is timed by the adjustment of the
low speed needle and shaft velocity. (i.e., if the
low speed needle is full soft, at high speed a
larger volume of oil will initially pass through the
low speed jet slightly delaying the operation of
the high speed bypass mode.)
Turning the black hex adjuster clockwise
increases the high speed damping. There are 18
clicks of high speed adjustment counting from full
soft.
NOTE: When making adjustments on the high
speed adjuster, start at the full soft setting (adjuster
wound all the way in against the reservoir body)
counting the clicks toward full firm. When adjusting
low speed, start at the full firm setting (adjuster
wound all the way in against high speed adjuster)
counting the clicks toward full soft. This makes your
settings more precise and less confusing for your
records.
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