10
SHOCK DAMPING – SHOCK OIL
Shock oil is rated with a “viscosity” number that indicates the thickness of the oil, which determines how much the oil resists fl owing and how much
it resists the shock piston moving through it. Shock oil with a higher viscosity (for example, 300cSt oil) is thicker than shock oil with a lower viscosity
(for example, 150cSt oil).
We recommend using only highest-grade XRAY Silicone Shock Oil, which is available in numerous viscosities. XRAY Silicone Shock Oil is specially
formulated to be temperature-resistant and low-foaming for use in XRAY shocks.
SHOCK ABSORBERS
SHOCK DAMPING
Shock damping manages the resistance of the shock to movement, as the internal shock piston moves through the shock oil when the shock
compresses and rebounds.
Damping mainly has an effect on how the car behaves on bumps and how it reacts initially to steering, braking, and acceleration. Damping only
comes into play when the suspension is moving (either vertical wheel or chassis movement or due to chassis roll), and loses its effect when the
suspension has reached a stable position. Without damping, the shock springs would cause the shock to “pogo” or “bounce” (compressing and
rebounding) until it stabilized.
When the shock is compressing or rebounding, the shock oil resists the movement of the piston through it. The amount of resistance is affected by
several factors:
• Viscosity (thickness) of the shock oil
• Restriction of oil fl ow through the piston (affected by the number of holes in the piston)
• Velocity (speed) of the piston
Damping is affected by both shock oil and shock piston settings; getting the optimum shock damping typically requires “hands on” experience.
Adjusting with...
Effect
Shock Oil
Piston Holes
FRONT SHOCKS
Softer damping
Thinner
More holes
• Slower steering response.
• Decreases initial steering at corner entry.
• Increases oversteer at corner exit/under acceleration.
Harder damping
Thicker
Less holes
• Faster steering response.
• Increases initial steering at corner entry.
• Increases understeer at corner exit/under acceleration.
SHOCK DAMPING – SHOCK PISTONS
Shock pistons affect shock damping by affecting how easily the piston travels through
the shock oil when the shock is compressing or decompressing (rebounding). The piston
has holes through which shock oil fl ows as the piston travels up and down inside the
shock body. The number of holes helps control how quickly the shock compresses or
decompresses.
The shocks of the XRAY NT1 may be built with either non-adjustable or 4-step adjustable
shock pistons.
• Non-adjustable pistons use a solid, 1-piece piston with a set number of holes in it. To
change the shock damping, you must disassemble the shocks and replace the piston
with another piston with a different number of holes.
• The XRAY adjustable shock pistons use a unique 2-piece piston assembly that can be
easily adjusted to align 1–4 holes.
359210
359215
359220
359225
359230
359235
359240
359245
359250
359260
359270
359280
359290
359301
359302
100cSt
150cSt
200cSt
250cSt
300cSt
350cSt
400cSt
450cSt
500cSt
600cSt
700cSt
800cSt
900cSt 1000cSt 2000cSt
EFFECTS OF SHOCK DAMPING ADJUSTMENT
The effects of damping are often diffi cult to distinguish since there is an adjustment where grip is optimum. When you get away from the optimum
damping setting, either softer or harder, the car will always lose grip.
The table below describes the handling effects by changing damping on one end of the car; the starting point is always the ideal “optimum.”
THIN
THICK
NON-ADJUSTABLE
ADJUSTABLE
Summary of Contents for NT1
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