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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

Page 1: ......

Page 2: ...Spring Preload 24 Adjusting Clutch Spring Preload 24 Clutch Gap 25 Effects of Clutch Gap Adjustment 25 Adjusting Clutch Gap 25 Clutchbell Endplay 25 Effects of Excessive Clutchbell Endplay 25 Adjustin...

Page 3: ...p track of your setup changes and record which setups work best at different racetracks under various conditions You can upload your NT1 setup settings to the XRAY Online Virtual Setup Sheet Database...

Page 4: ...ated in the table below The order of the chassis settings has been determined as the most logical to set up your NT1 chassis properly and easily Also certain chassis settings must be made before other...

Page 5: ...the car s CG causing the car to tilt backward This transfers weight to the rear wheels When the car brakes the force pushes forward on the car s CG causing the car to tilt forward This transfers weigh...

Page 6: ...etter on bumpy tracks Rear Downstops Higher rear downstop value Decreases rear chassis upward travel off throttle or under braking Increases stability under braking Better on smooth tracks Lower rear...

Page 7: ...lower arm rises DECREASE front downstop Turn OUT CCW the front downstop screw so the front lower arm drops IMPORTANT Measure the front downstop under the steering block ADJUSTING REAR DOWNSTOPS Set t...

Page 8: ...p conditions Better for bumpy and very large and open tracks Springs that are too soft make the car feel sluggish and slow allowing more chassis roll Stiffer front springs Increases mid corner and cor...

Page 9: ...For more information see section Tweak Shock spring preload is NOT used for Spring preload does not alter camber or other suspension settings or characteristics Spring preload does not alter spring t...

Page 10: ...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 cor...

Page 11: ...lick when you turn the piston rod Full CW aligns 1 hole hardest setting Full CCW aligns 4 holes softest setting 4 Re attach the shock lower mount to the arm SHOCK ABSORBERS HARDEST SOFTEST 1 2 3 4 Adj...

Page 12: ...ollows Use the following set up components Shocks Attach the shocks Wheels Attach the wheels Flat setup board decal MEASURING REAR TRACK WIDTH Measure rear track width on the outside edges of the rear...

Page 13: ...RIDE HEIGHT AND TIRES The car s ride height decreases as the foam tires wear down to smaller diameters The foam tires may wear at different rates front to back and left to right which may eventually r...

Page 14: ...n the rear shocks increasing the preload This moves the collars DOWN the shock bodies DECREASE lower rear ride height LOOSEN the spring preload collars on the rear shocks decreasing the preload This m...

Page 15: ...ssembled set up stands Setup Stand Camber Values Each graduated camber mark on a setup stand indicates a 1 camber value You should be able to set camber with a resolution of 0 5 ADJUSTING CAMBER Adjus...

Page 16: ...of caster this can increase steering but if too much the tire only runs on the inside edge and loses its contact patch and grip Compare that with static camber angle of the wheels which is adjusted w...

Page 17: ...tion as it introduces friction and therefore some slip in the tires Front wheels can have either toe in toe out or be parallel Rear wheels should always have toe in they should never have toe out Rear...

Page 18: ...e atop the rear set up stands The pins at the top of the stands t in the machined slots in the toe gauge 2 To read the toe value of a rear wheel push the toe gauge to the other side until the pin on t...

Page 19: ...TOE Anti roll bars are used to adjust the car s side lateral grip They can also be used in conjunction with a softer spring rate to handle bumpy tracks more efficiently without excessive chassis roll...

Page 20: ...djustment varies depending on the type of shock absorber BINDING PARTS Make sure that all suspension components move freely without binding this includes suspension arms and pins pivotballs ball cups...

Page 21: ...ront right wheel lifts rst INCREASE the preload on the rear left spring and DECREASE the preload on the rear right spring by an equal but opposite amount CORRECTING REAR TWEAK STEP 2 ANTI ROLL BAR Aft...

Page 22: ...h front springs in equal but opposite directions otherwise you will change the front ride height Example If the rear right wheel lifts rst INCREASE the preload on the front left spring and DECREASE th...

Page 23: ...A CLUTCH When building the XCA clutch it is very important to shim it properly for proper operation and long life An improperly built clutch may cause excessive slip too early or too late engagement e...

Page 24: ...spring preload collar to an initial value of 10 11 mm from the end of the crankshaft to the outer edge of the collar This is an initial value ONLY and must be adjusted at the track Adjust clutch sprin...

Page 25: ...clutch shoe and then measure the distance A as indicated 3 Pull the clutchbell away from the clutch shoe and then measure the distance B as indicated 4 The clutch shoe clearance is calculated as A B...

Page 26: ...dif cult corners or sections this will lead to inconsistency and tendency to overshoot those corners or misdrive those sections Adjust the shift point so the car is easy to drive on the particular tra...

Page 27: ...etscrews equally so that each one just lightly touches the central adaptor The setscrews MUST NOT protrude beyond the shoes 2 Install the drive pin in the layshaft 3 Slide the 2nd gear shoe assembly o...

Page 28: ...onditions or driving styles the middle of the chassis can be additionally reinforced by installing optional MFT 1 piece engine mount which features reinforcing legs both front and rear reinforcing the...

Page 29: ...CG to rotate around the RC Since the RC is below the CG cornering force causes the car to rotate AWAY from the force Hence the car rolls to the OUTSIDE of the corner When the RC is far away from CG l...

Page 30: ...balance out the overall grip between the front and rear Use the same settings on the left and right sides of the car Each matched pair of roll center inserts at ends of a pin must have the same posit...

Page 31: ...sitions REAR ROLL CENTER TOWER camber link inner mounting positions Lower holes inner or outer Higher rear roll center Upper holes inner or outer Lower rear roll center REAR UPRIGHT camber link outer...

Page 32: ...sents the camber rise ADJUSTING CAMBER RISE Adjust camber rise by changing the inner and outer mounting positions of the rear upper camber link MORE camber rise SHORTER camber link LESS camber rise LO...

Page 33: ...mann is to get the car to keep a consistent steering arc after going from off power to on power while not allowing the front inside wheel to be turned too much and drag through the corners instead of...

Page 34: ...ndency to understeer heavily under throttle and turn in oversteer as soon as you lift Less on throttle oversteer snap oversteer Less turn in understeer Less stable under braking Heavier diff action th...

Page 35: ...XRAY Multi Diff set to front solid one way mode both outdrives left and right are connected together by internal locking axle but are not connected to front main axle XRAY MULTI DIFF FRONT SOLID ONE...

Page 36: ...side pulley used The rear DTR of the XRAY NT1 is permanently set to 2 05 The front DTR value may be changed by using different mid side pulleys When using the 26T mid side pulley the front DTR is 2 05...

Page 37: ...verdrive ratio The front and rear wheels rotate at the same speed When using the 25T mid side pulley the front internal ratio DTR becomes 1 97 When compared to the rear DTR of 2 05 the overdrive ratio...

Page 38: ...ately 25 rebound low rebound suggested for very high traction track During the Rebound Adjustment procedure shock oil will leak out of the shock body through the O ring on the shock rod this is normal...

Page 39: ...ght bearing oil The ball bearings are subjected to high heat for extended periods and have a tendency to get rusty after a short time which may lead to failure if not oiled PREVENTING CHUNKING Aside f...

Page 40: ...C AMERICA 167 TURTLE CREEK BLVD SUITE C DALLAS 752 07 TEXAS USA PHONE 214 744 2400 FAX 214 744 2401 xray rcamerica com RC AMERICA 167 TURTLE CREEK BLVD SUITE C DALLAS 752 07 TEXAS USA PHONE 214 744 24...

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