- New chassis layout with diff, motor and battery moved forward makes the XT4 faster and easier to drive
- Front & rear bulkheads with Horizontal Split Design (HS)
- Front and rear diff height adjustment
- Central drivetrain angle and pinion height adjustment
- Longer front and rear central drive shafts and shortened pinion gears improve drivetrain efficiency
- Revised chassis with forward design and improved flex
- New shorter front lower chassis brace to accommodate the more forward layout
- New front lower graphite chassis brace to match the more forward layout
- Center dogbones for better performance and less maintenance
- New front & rear diff outdrives for center dogbones with inner O-rings to eliminate damage in high impacts
- New redesigned servo holder matches new chassis design and the more forward layout
- Side guards have now symmetrical mounting to the chassis left and right
- Shorter radio plate is fitted directly on chassis so it has no negative effect on chassis flex
- All-new front & rear suspension holders with extra wide range of set-up adjustments
- All-new tweak-free Quick Battery Holder featuring smart height adjustment
- Chassis features multiple battery mounting positions with various O-ring diameters for every battery size
- All-new servo saver stands to accommodate the new front Horizontal Split Bulkhead (HS)
Made in Europe.
Designed, developed, and fully manufactured in-house at the XRAY factory in Slovakia, Europe, using the most high-tech German and Swiss machines and premium European materials, crafted with XRAY’s legendary attention to detail by our artistic production specialists. The XT4 is truly a masterpiece.
The XT4’s revised chassis is shared with the XB4’22 and moves the motor and central driveline weight further forward. It features new side guard mounting positions for symmetrical flex, new fan holder mounting positions and multiple battery position choices to adjust the weight balance.
The front & rear bulkheads feature a horizontal split design (HS) to retain easy diff access while adding the valuable new diff height adjustment.
Diff Height Adjustment.
The front & rear HS bulkheads incorporate a diff height adjustment using eccentric bushings. In the front gearbox, the diff height has 3 possible settings. The rear differential can be adjusted through a 5mm range. The diff height is a valuable adjustment that allows for quick set-up adaption.
Diff Height Adjustment.
Central Drive Train.
The design of the HS bulkhead’s inline bushing for the bevel drive gear keeps the gear properly matched to the diff height position. It also creates a more linear orientation for the front center drive shaft, reducing the CV joint angle for increased efficiency and decreased friction and wear. The height of the rear center drive gear is also adjustable to match the height adjustment of the differential.
- Front – there are 3 different angle configurations for adjustment of the front drive train.
- Rear – there are 6 different height configurations for adjustment of the rear drive train.
The new pinion gear is shorter to move CV joint closer to the differential, reducing the driveshaft angle and improving drive train efficiency.
Both crown gear and pinion gear are CNC-machined from HUDY Spring Steel and are ultra-hardened making them very strong and reliable with a longer life span. The split crown gear allows for a simpler change to optional gears without rebuilding the internal diff assembly and results in significantly lower rotating mass and improves the serviceability.
To improve the gear engagement both crown gear and pinion gear have more teeth and new geometry that results in smoother engagement and increased efficiency.
The new chassis layout moves the center diff, motor and battery significantly forwards and increases stability, allowing for more aggressive landings and making the truck more forgiving.
The optional front chassis t-brace increases front stability on high traction tracks, making the XT4 more predictable and easier to drive. The rear graphite chassis brace is installed over the lower composite brace connected directly to the chassis. The graphite brace reinforces the rear chassis structure and provides more stability and traction as well.
The chassis braces are a vital part of the Multi-Flex™ adjustability.
Central Dogbone Drive Shafts.
The central drivetrain features new outdrives and dogbone driveshafts that offer reduced maintenance compared to previous CVD drive shafts.
The servo mount was redesigned to fit the new frontward chassis layout and features two aluminum stands with graphite stiffener from top.
Side guards are updated to match the new chassis layout. The new version offers symmetric mounting positions on the chassis to ensure equal left-to-right flex characteristics.
A handy, compact electronics plate for speed control mounting provides quick & easy removal and assembly. Redesigned to fit the new chassis layout and side guards, the plate is now mounted directly to the chassis instead of the side guards to reduce the impact on chassis flex characteristics.
All-new front & rear shock towers are redesigned to accommodate the Horizontal Split Bulkheads (HS) and provide multiple upper shock mount positions for more precise set-up adjustments.
Both front & rear shock towers are machined from premium-grade graphite and are lightweight & strong, with multiple shock positions and roll center adjustment positions.
I.S.S.™ Suspension Holders.
The front & rear suspension holders are redesigned to mount to the new HS bulkheads and offer an expanded range of set-up adjustment.
The rear suspension holders can be installed in upward or downward orientations, resulting in additional roll center locations for the inner hinge pins.
The downward orientation of the suspension holder is used primarily for Dirt tracks.
The upward orientation of the suspension holder is used primarily for Carpet tracks.
Machined from premium Swiss 7075 T6 aluminum and black coated.
All-new tweak-free Quick Battery Holder allows for easy retainer height adjustment for more convenient battery mounting. The entire system is intended to reduce the effects of the battery and holders on chassis flex, making the XT4 more predictable and easier to drive.
The rear body mount plate moves the body post forward and is shaped to fit the new rear Horizontal Split Bulkhead (HS). The shape of the holder provides super easy access to the screws on the upper part of the bulkhead for easier maintenance. Machined from premium graphite material.
The dual arm steering system is simple yet effective, featuring an easily adjustable integrated servo saver. Ackermann is easily adjusted by quickly changing the steering link mounting positions on the steering plate.
Bump steer is adjusted for more aggression by inserting a shim between the steering block and steering linkage.
Some information shown below may include details from previous kits, and it may vary slightly from current kit specifications.
The front and rear gear differential features a split design of the cover and crown gear. The differential case has greater internal oil volume to increase consistency of the diff action, yet it is significantly narrower and to move the rotating weight closer to the centerline.
The super-smooth, low maintenance gear diff includes a composite case and cover with internal satellite gears that are precision-molded from special XRAY-developed graphite composite material, ensuring a long lifespan and super-smooth, efficient operation.
Gear differential features all-new diff-outdrives designed for use with 2.5mm pin.
Central Gear Differential.
The maintenance-free, super-smooth gear diff has greater internal oil volume to increase consistency of the diff action and includes a composite case and cover with internal satellite gears that are precision-molded from special XRAY-developed graphite composite material, ensuring a long lifespan and super-smooth, efficient operation.
The differential outdrives are designed for use with 2.5mm driveshaft pins. The gear diff set includes an 81T spur gear and a 78T spur gear is available as an option.
The central differential is recommended for use on clay, bumpy Astro and low-traction tracks to increase traction.
The front and rear driveshaft lengths are updated to match the differential width and suspension geometry; the front drive shaft is 99mm long and the rear drive shaft is 94mm long.
The safety collar on the front driveshaft secures the pin and coupler, while the inner ball bearing captures the pin in the rear axles, preventing both assemblies from coming lose during a run.
XT4 constant velocity drive shafts are manufactured from world-renowned HUDY Spring Steel™ and feature 2.5mm drive pins for maximum drivetrain efficiency. The drive shafts are some of the world‘s thinnest yet most durable drive shafts used in electric off-road cars. Hardened with a proprietary hardening process, the drive shafts provide unbeatable lifespan and reliability.
The motor mounting plate features a shape for easier access to the pinion gear set screw. The inner motor screw is recessed into the mount for improved clearance around the center spur gear.
The motor is connected to an eccentric mounting plate, with the assembly then inserted into an integrated motor holder/drivetrain support. The design allows quick & easy motor rotation to adjust gear mesh, and still securely holds the motor plate using only a single screw.
To ensure the motor will not loosen in a serious crash or due to insufficient tightening, the motor plate has a bayonet mounting system which prevents it from being dislodged from the motor holder. By rotating the motor mount plate to the opposite direction, the motor can be quickly removed from the vehicle.
Removing the motor or adjusting the gear mesh is easy and fast, with changes possible in only a few seconds.
Multi-Adjustable Rear Suspension.
The rear suspension features adjustable rear-upright design, longer CVD drive shafts and longer, rear camber link. The rear suspension offers a vast range of roll-center tuning adjustments for different track conditions.
Rear uprights feature multiple set-up options for upper & lower roll centers. The upper roll center is adjusted at the camber linkage via shims (up/down & in/out) while the lower roll center is adjustable to 9 different positions via eccentric inserts (up/down & in/out).
The multi-function uprights have the upper roll center position in the middle-axis of the drive shaft’s connecting joint to help generate more traction and increase stability.
There are three different uprights available: hard (included,) graphite (optional) and aluminum (optional), each suitable for a different range of track conditions.
The XT4 comes equipped with offset hexes to perfectly match the width of the truck to the new suspension arms and hubs.
Ultra-lightweight 12mm wheel hex-drive hubs are CNC-machined from Swiss 7075 T6 black-coated aluminum. These ultra-true hex hubs have a clamping design to ensure ultra-solid mounting of the wheel’s hub.
To adjust track-width, optional offset wheel hex-drive hubs are available.
The suspension arms are rigid enough to provide a responsive feel; yet soft enough for extreme durability. The exclusive composite mixtures used for suspension arms are a perfect balance between reliability and performance.
There are three different rear suspension arms available: medium (optional), hard (included) and graphite (optional), each suitable for particular track conditions.
The tiny yet tough steering blocks are molded from a special composite mixture for maximum strength.
Composite steering block inserts allow for very quick & easy lower roll center adjustment. With additional shims and extra inserts, fine tuning the roll center is easily achieved.
For maximum drivetrain reliability, larger 5×12 ball-bearings are used in the outer position with increased dynamic load. On the inner position, the smaller 5×10 ball-bearings are used for minimized unsprung weight.
The 1-piece caster blocks are very lightweight, yet the construction makes them very stiff and rigid. The non-adjustable caster angle is preset to 9°. Roll center position can be quickly & easily adjusted by inserting different thickness of shims atop the caster block (between the block and the vertical ball stud).
The front of the chassis is pre-angled with an integrated 8° caster angle, however the position of the adjustable eccentric bushings in the I.S.S.™ suspension holders influences the caster as well. (For example, if the eccentric bushings have the roll center in middle position, the caster angle is 9° which when added to the 9° caster block gives a total of 18° caster. The total adjustability range for caster is 16-20°.)
Optional caster blocks with 6° and 12° built-in caster angles are available for further suspension geometry adjustment.
There are four different caster blocks available: medium (optional), hard (included), graphite (optional) and aluminum (optional), each suitable for particular track conditions.
Precision-molded spur gears are made from XRAY’s exclusive secret blend of composite material, allowing the gear to run true yet be robust enough to handle high-performance brushless motors. The spur gears are designed to have the lowest possible weight while staying strong and light. Each gear is stamped with the tooth number for easy identification.
The XT4 is equipped with an 81T spur gear which suits the majority of tracks. For additional tuning, optional 78T spur gear is available.
The shocks are membrane-free, yet they still allow for easy, consistent building and rebound setting using the bleed-screw shock cap design.
The aluminum body and lower cap are machined from premium Swiss 7075 T6 aluminum.
Shock rods are machined from special steel material, precision hand-ground for maximum smooth operation, and additionally hardened for improved lifespan.
Shock pistons are made from Delrin® and are molded using ultra-high precision moulds. All-new 2-hole pistons (1.6mm and 1.7mm holes) are now included in the set.
The XT4 springs have been specifically designed to complement the shocks.
The XT4 springs, like all other XRAY springs, are manually measured, selected, and matched into pairs to guarantee precisely equal length and damping characteristics.
Anti-roll bars are manufactured from special spring steel material and are included to stabilize the front & rear ends of the truck. The roll bars are easily mounted to the diff cases and can be adjusted with the linkages.
Both front & rear anti-roll bars are interchangeable since they have same shape. Anti-roll bar wires of different thickness are optionally available for fine-tuning. The thickness of each anti-roll bar is laser-engraved for easy identification.
The high performance low profile aerodynamic body was designed by XRAY to perfectly fit the XT4 and to work in most track conditions effectively.
The front and rear of the body have been designed to provide downforce for maximum stability of the truck. The body sides as well the cockpit sides are as flat as possible to allow the air flow around the body for the side stability. On the top of roof two flow channels are incorporated for proper air flow.
The body is made from high quality premium Lexan material.
Stylish and effective rear wing works perfectly with the XRAY XT4 body. Made from strong Lexan™ material, the wing is supported on the mounts by extra flat shims to better support and extend the life of the wing.
Optional thicker 1.5mm (#363511) and 2.0mm (#363512) rear wings are highly reliable with less chance of breakage, while at the same time influencing the performance of the truck. The thicker wing gives higher traction and stability but can reduce steering.
The XT4 features greased ball-bearings for front steering blocks & rear uprights to increase lifespan in dusty conditions. The remaining bearings are degreased and oiled with AeroShell® Fluid 12 for maximum smoothness and long life.
A full set of high-speed ball-bearings are used throughout the drivetrain to ensure maximum efficiency.
HUDY Exclusive Silicone Oils are manufactured in Europe and each batch is laboratory tested and calibrated to ensure the highest possible consistency and quality from batch to batch. Based on the industry-standard cSt rating, the new line of oils will be easy to identify, adjust, and feel.
When following any set-up sheets by XRAY or XRAY team drivers, you can be sure that the oils you will get for your car are exactly same as those used by the factory racing team, thus ensuring very exacting set-ups and handling.
HUDY Chem Series.
The XT4 includes premium #106210 HUDY Graphite Grease which is a high-performance, advanced-technology semi-fluid lubricant which incorporates both extreme pressure additives and finely-dispersed graphite for load carrying. It is intended primarily for the lubrication of rotating parts and loaded gears. In addition to providing outstanding load carrying, it is formulated to have excellent adhesion and resistance to “fling-off” under extreme conditions. The grease reduces wear and increases parts life.
XRAY Instruction Manual.
XRAY Instruction Manuals have become the industry standard, being simply the best manuals you will ever get with an RC model car. Whether you are a first-time builder or an experienced racer, all the instructions are straight-forward and easy to understand. The full-color instruction manual contains large 3D illustrations that show all assembly details in the clearest possible way.
The XT4 is one of the most adjustable electric truggies in the world. Whether you are a hardcore racing fanatic or a club-level sportsman, you can very easily adjust the XT4 to suit your racing style, race track type, and all track conditions. To fully understand the set-up possibilities we recommend the legendary HUDY Set-up Book, loaded with over 40 pages of high-quality pictures and easy-to-understand RC car set-up explanations. Whether you are a novice driver or experienced racer, you can easily learn many set-up tips & tricks and improve your set-up skills, ultimately translating into improved racing performance with your XT4.The HUDY Set-up Book is available for download exclusively at www.hudy.net
XRAY VIP Customer Treatment.
Owning an XRAY model racing car is an experience on its own. Not only will you own the most premium luxury model racing car in the world, but you will also become a member of the prestigious family of XRAY owners with direct support and service from the XRAY factory. XRAY brings you the most up-to-date RC Web site on the Internet, with daily racing news and latest product developments. If you have any questions, problems or comments, you can ask the XRAY Support Team or any XRAY Factory Team Driver on the XRAY Support Forum. You can even upload your own set-up sheets or download from the thousands of different set-up sheets available from all around the world at the exclusive XRAY Virtual Set-up Sheet Database, the world’s largest set-up sheet database. And that is only the start of the VIP treatment you get by joining Team XRAY.
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