SETUP THEORY Setting up a racecar with fully independent suspension, like your XRAY T, is necessary to make the car perform well. We have developed these straightforward procedures to help you set up your car properly and easily. Always follow these procedures step-by-step, in the order presented, and always make sure that you make equal adjustments on both left and right sides of the car.
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WEIGHT TRANSFER WEIGHT TRaNSFER Weight transfer is the key to car handling. Consider that a car has a certain amount of “weight” on various parts of the car and this weight is distributed by a certain amount into each wheel. When the car corners, weight is transferred to the outside tires, when it accelerates weight is transferred to the rear, and when it brakes weight is transferred to the front.
DOWNSTOPS dOWNSTOPS - THEORY FRONT RIdE HEIGHT REaR RIdE HEIGHT Downstops limit how far the suspension arms travel downward, which determines how far upward the chassis rises. This affects the car’s handling (due to effects on camber and roll-center) and the ability of the tires to “follow” the track. The effects may change with the type of track and/or amount of grip available.
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DOWNSTOPS . Lift and drop the suspension arms so that they settle in their lowest positions. . Using the droop gauge, measure the downstop value. frOnT DOWnSTOpS Measure at the bottom of the front arms. Do NOT measure under the front C-hub. reAr DOWnSTOpS Measure at the bottom of the rear arms.
RIDE HEIGHT RIdE HEIGHT - THEORY ride height rear ride height front Ride height is the height of the chassis in relation to the surface it is sitting on, with the car ready to run. Ride height affects the car’s traction since it alters the car’s center of gravity and roll center.
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RIDE HEIGHT 1. Place the car on the set-up board. . Push down and release the front and rear of the car so that the suspension settles. . Measure the ride height using the ride height gauge at the front and rear of the car at the lowest points of the chassis.
DROOP dROOP - THEORY Droop refers to the amount that the chassis travels downward after the car is dropped and the wheels touch the ground; it is also the amount that the chassis travels upward before the wheels lift from the ground. Droop is a very powerful way to adjust your car’s handling, as it adjusts the weight transfer of the car.
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DROOP 1. Place the car on the set-up board. . Push down and release the front and rear of the car so that the suspension settles. . Place the ruler vertically beside the chassis, so that you can see how much distance there is between the flat surface and the bottom of the chassis.
TRACK-WIDTH TRacK-WIdTH - THEORY Track-width is the distance between the outside edges of the wheels, front or rear, and it affects the car’s handling and steering response. It is important that front or rear track-width is adjusted symmetrically, meaning that the left and right wheels must be the same distance from the centerline of the chassis.
STEERING THROW SYMMETRY STEERING THROW SYMMETRY - THEORY Although most cars‘ front suspension geometry is designed such that the turning radius of the car is the same from left to right, sometimes this isn‘t the case. You can use the toe gauge plate to make sure that the steering turns as sharply to the left as it does to the right. If it is not the case and if your radio has EPA (End Point Adjustments), adjust the EPA on your transmitter in order to achieve steering throw symmetry.
CAMBER caMBER - THEORY Camber is the angle of a wheel to the surface on which the car is resting (with wheels and shock absorbers mounted). Zero degrees (0°) of camber means that the wheel is perpendicular to the reference surface. Negative camber means that the top of the wheel is leaning inwards towards the centerline of the car.
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CAMBER Each graduated mark indicates a 1° camber value. You should be able to set camber with a resolution of 0.° caMBER - adJUSTING frOnT cAmBer Increase (more –ve) SHORTEN the front upper camber link. Decrease (less –ve) LENGTHEN the front upper camber link. reAr cAmBer Increase (more –ve) SHORTEN the rear upper camber link.
CASTER caSTER - THEORY Caster describes the forward/backward angle of the front steering block with respect to a line perpendicular to the ground. Caster angle affects on- and off-power steering, as it tilts the chassis more or less depending on how much caster is set. Generally, a lower caster angle (more upright) is better on slippery, inconsistent, and rough surfaces, and a higher caster angle (more inclined) is better on smooth, high-traction surfaces.
The size and geometry of the servo saver on XRAY cars forces the inside wheel to increase its turning angle at a greater rate than the outside wheel, as the servo turns either way from center.
TOE - THEORY Toe is the angle of the wheels when looked at from above the car. Toe is used to stabilize the car at the expense of traction, as it introduces friction and therefore some slip in the tires. When the wheels are parallel with the centerline of the car, toe is 0°...
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To read the toe value of the right rear wheel, push the toe gauge to the left until the pin on the top edge of the right set-up stand hits the edge of the slot in the toe gauge. Read the measurement. When using the acrylic toe gauge, the toe gauge does not fit over the pins on the set-up stands so that the toe gauge is in one position.
TWEAK TWEaK - THEORY A “tweaked” car is an unbalanced car, and has a tendency to pull to one side under acceleration or braking. Tweak is caused by an uneven wheel-load on one particular axle. You should check for suspension tweak after you have set up the suspension settings. The HUDY All-In-One Set-Up System uses a unique tweak station to set and measure tweak.
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TWEAK nO TWeAk Reference marks on the sides of the tweak station align with the long central marks on the level. TWeAkeD Reference marks on the sides of the tweak station DO NOT ALIGN with the long central marks on the level.
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TWEAK adJUSTING TWEaK USING SPRING PRELOad Adjusting tweak using spring preload should be done only after all other items have been checked and corrected. Incorrectly adjusted springs can result in one side of the car being firmer or higher than the other, causing handling differences when turning left or right. After adjusting spring preload to remove tweak, if the preload on the left and right sides of the car are different by more than 1~1.mm, then you should start over again and check for other areas that may result in tweak.
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TWEAK adJUSTING TWEaK USING aNTI-ROLL BaRS This section describes how to interpret the meaning of the tweak station readings, and the adjustments to make to the car’s anti-roll bars to remove tweak. Adjusting tweak using anti-roll bars with anti-roll bars attached. This section describes how to adjust tweak when using “wire-type”...
ROll CENTER ROLL cENTER A “roll center” is a theoretical point around which the chassis rolls, and is determined by the design of the suspension. Front and rear suspensions normally have different roll centers. The “roll axis” is the imaginary line between the front and rear roll centers.
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• Better on tracks with quick direction changes (chicanes). ROLL cENTER – adJUSTING ON THE T2 Adjusting the T front or rear roll center 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.
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Outer Pivot Raise and/or move inward the inner pivot mounting position Front upper using the XRAY Quick Roll Center positions on the shock tower. camber link Lowering front • Lower the outer pivot by removing shims from in between the link and the hub.
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• Decrease the height of the camber link OUTER ball joint by removing shims in between the joint and the hub. • Increase the height of the camber link INNER ball joint by using one of the upper XRAY Quick Roll Center™ positions on the shock tower •...
However, the flex characteristics they provide alone are still inadequate when extreme changes are needed. With XRAY Multi-Flex Technology™ (MFT), drivers can now not only change the amount of overall flex to the extreme, but they are also able to fine- tune the differing characteristics of both torsional (twisting) and lateral (front to rear) flex.
XRAY MUlTI-FlEX TECHNOlOGY™ TOP-dEcK FLEX SETTING STIFF SETTING screw not used screw used MEdIUM SETTING screw not used screw used SOFT SETTING screw not used screw used...
0lb spring). XRAY shock springs are color-coded so that all springs of a specific “spring weight” have the same external colour. Note that spring colours are NOT standardized; an XRAY silver spring will not have the same spring tension as a silver spring from another manufacturer.
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Silicone Shock Oil is specially formulated to be temperature-resistant and low-foaming for use in XRAY shocks. 30 9540 SILICONE OIL 40W To be able to compare your setup with other XRAY drivers, we advise using only XRAY Silicone Shock Oil. 30 9550 SILICONE OIL 50W...
WHEElBASE wheelbase Wheelbase refers to the horizontal distance between the front and rear axles. Changes to wheelbase can have a dramatic effect on the handling of your car, since it readjusts the distribution of weight on the wheels, which adjusts traction. Not all R/C cars have the option to adjust the wheelbase.
ANTI-ROLL BARS 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 at mid-corner. Anti-roll bars resist chassis roll and by doing so transfer wheel load from the inside wheel to the outside wheel.
• solid one-way axle* • solid front axle* * Modes available in XRAY Multi-Diff™ BaLL dIFFERENTIaLS Differentials allow the wheels at opposite ends of the same axle to rotate at different speeds. Why is this important? When a car turns in a circle, the outer wheel has a larger diameter circle to follow than the inner wheel, so it needs to rotate faster to keep up.
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(Left) When using an XRAY Multi-Diff™ in “full-time solid axle” mode, both outdrive shafts (left and right) are connected to front main axle by internal locking axle and locking pin. The car achieves maximum WD braking, while being very stable and easy to drive.
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Outdrive shaft (Left) When using an XRAY Multi-Diff™ in “one-way” mode, outdrive shafts (left and right) are not connected to each other, nor to front main axle. This mode combines the characteristics of a solid axle and a differential. Off-power & braking Front inner and outer wheels rotate forward independently of each other, making axle behave like a front ball (corner entry &...
GEARING GEaRING Proper gearing is one of the most essential tuning options required to maximize the performance potential of a touring car. The key to proper gearing is finding and maintaining the best “rollout” for each track environment, motor/chassis setup and driving style. Rollout is the distance a car will travel in one revolution of the motor shaft.
SHOCK BUIlDING TIPS BUILdING SHOcKS cOmpOSITe pArTS prepArATIOn Carefully use a hobby knife (at a perpendicular angle) or fine file to gently remove excess composite material from the outer edge of each piston. This is a critical step; the outer edges of the shock pistons must be smooth and round. lOWer SHOck BAll jOInT InSTAllATIOn 1.
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