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REAR ROLL CENTER

Rear roll center affects 
on- and off-throttle situations in 
all cornering stages.

Rear Roll Center

Effect

Lower

• Increases on-throttle grip. 
• Decreases weight transfer at rear of car, but increases grip. 
• Increases grip, decreases rear tire wear. 
• Increases chassis roll. 
• Use to avoid traction rolling at corner entry (increases rear grip). 
• Better on low-traction tracks.

Higher

• Decreases on-throttle steering. 
• Increases weight transfer at front of car, but decreases grip. 
• Increases car’s responsiveness. 
• Decreases chassis roll. 
• Use in high-grip conditions to avoid traction rolling in mid-corner and corner exit.
• Better on tracks with quick direction changes (chicanes).

ADJUSTING ROLL CENTER

Adjusting the front or rear roll center on the NT1 is the best way to change mid-corner grip at either end of the car, as well as to 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 position.
•  Changing roll center settings impacts several other settings on the car, such as downstops, camber, and ride height. 

When changing front or rear roll center, re-check your other settings.

ADJUSTING FRONT ROLL CENTER

Adjust front roll center by changing the front upper pivot pin inserts.

ADJUSTING REAR ROLL CENTER

Rear roll center on the XRAY NT1 can be adjusted in two manners: 

•  LARGE ADJUSTMENTS: Change the rear lower pivot pin inserts.

•  FINE TUNING: Change the inner and outer mounting positions of the 

rear camber link

LARGE REAR ROLL CENTER ADJUSTMENTS

Make large adjustment to rear roll center by changing the rear lower 
pivot pin inserts.

Effect on Front Roll Center

Lowest

                          

Highest

Front Upper Insert 
Position

+1.5

+0.5

-0.5

-1.5

Effect on Rear Roll Center

Lowest

                           

Highest

Rear Lower Insert 
Position

-1.5

-0.5

+0.5

+1.5

ROLL CENTER

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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