Penske Racing Shocks 7300 Series - Manual (Page 11)

VDP and Digressive Valving Information Options
Part # Part # Part#
.004 VW-2NX.004 .004 VW-5NX.004 .004 VW-8NX.004
.006 VW-2NX.006 .006 VW-5NX.006 .006 VW-8NX.006
.008 VW-2NX.008 .008 VW-5NX.008 .008 VW-8NX.008
2 Notch 5 Notch 8 Notch
1.350 O.D. 1.350 O.D. 1.350 O.D.
Preload Shim Spacers
Part#
.004 x .750 VW-23
.006 x .750 VW-25
.008 x .750 VW-27
.010 x .750 VW-29
.012 x .750 VW-31
.015 x .750 VW-33
.020 x .750 VW-00
Part #
.004 VS-37
.006 VS-39
.008 VS-41
.010 VS-43
.012 VS-45
.015 VS-47
VDP 55mm Linear Base Shim
1.235 O.D.
Flow Rate Through Slotted Shims
Equivalent
Shim Number Relative Bleed Hole Ø
Thickness of Notches Flow Rate (1) Hole
0.004 2 0.48 0.022
0.004 5 1.20 0.035
0.004 8 1.93 0.044
0.006 2 0.64 0.025
0.006 5 1.61 0.040
0.006 8 2.57 0.051
0.008 2 0.86 0.029
0.008 5 2.14 0.046
0.008 8 3.42 0.059
These flow rate values are dimensionless
and have no real meaning by themselves.
They are simply used to cross-reference
the amount of flow between different bleed
hole or slot combinations. For example,
four Ø.010” holes would have the same
flow rate as one Ø.020” hole (with a flow
rate of 0.40). The flow rates can also be
added, so a piston with three Ø.015” and
three Ø.020” holes would have a total flow
rate value of 0.68 + 1.20 = 1.88 which
would be the same as three Ø.025” holes.