Penske Racing Shocks 7800 Series - Manual (Page 6)

6
General Valving Characteristics
The damping characteristics of your shock are determined by the
compression and rebound valve stacks located on the main piston.
The valve stacks are made up of a series of high quality shims, which are
made to flex under the force of oil flowing through the piston ports and
then return to their original state.
The thickness of the individual shims determines the amount of damping
force the shock will produce. By changing the thickness of the individual
shims, damping forces will be altered. For example, if you are running an
“3” compression valving, where all the shims in the stack are .XXX thick
and you replace them with a “4” compression valving, which consists of all
.XXX thick shims, the compression damping will increase.
* When the shaft is moving very slowly oil passes through the bleed
hole(s), if there is one, before it passes to the shims.
High Speed Low Speed* High Speed
Rebound Compression and Rebound Compression