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 trademark attention to detail by our production specialists. The X4 is truly a masterpiece.

The X4 platform was tested for improvements across all track conditions to provide race-ready performance out of the box. Even with this goal, there are still differences in track conditions that can require different components for the best results.

To allow the customer to choose their ideal starting point, there are three versions of the X4: the Graphite, Flex Aluminum and Solid Aluminum Edition, each tuned for different track conditions.

The Graphite edition is intended for asphalt tracks and low traction carpet tracks.

The Aluminum Flex edition is suitable for many carpet tracks and high traction asphalt tracks.

The Aluminum Solid edition is configured for high bite carpet tracks such as US black carpet style.

The X4 chassis is designed for the new CFF™ suspension arms that are mounted via pivot balls directly to the chassis.

The X4 chassis works together with the new motor mount and bulkheads using alignment holes for the centering pins on each of the mounted components. Thanks to the centering pins, the assembly of structural components is hassle free, and most importantly the parts resist movement in a crash to let you finish the race without losing pace.

Retained from our previous touring car platform, the mid motor chassis layout is designed around the centered drivetrain system.

The narrower design of the chassis together with the perfectly symmetrical shape provide optimal flex characteristics.

The bottom of the alu chassis is tapered to reduce contact between the chassis and the track to improve cornering speed.

There are three chassis alternatives to tune your X4 to any track conditions: 2.2mm graphite or 2.0mm aluminum flex chassis or 2.0mm aluminum solid chassis.

The symmetric X4 chassis creates equal side to side flex.

There are three chassis alternatives to choose from when configuring your X4:

The 2.2mm thick graphite chassis is CNC-machined from premium-grade material. This chassis is developed for all asphalt conditions. The narrow chassis is only 84mm wide with a variety of chassis flex adjustments that help to generate exceptional traction and give excellent steering characteristics.

The 2.0mm thick aluminum flex chassis is CNC-machined from premium Swiss 7075 T6 aluminum, then black coated and laser engraved. The narrow chassis is also 84mm wide and features special cut outs that provide the chassis flex characteristics suitable for a variety of the medium grip surfaces. The bottom edge of the chassis is tapered to reduce contact between the chassis and the ground during cornering to improve speed.

The 2.0mm solid aluminum chassis is available for high traction conditions like the black carpet tracks found in the USA. Made from the same 7075 T6 aluminum as the flex chassis, the solid aluminum plate lacks the flex cutouts to maintain the stiffness needed on high bite situations.

The X4 bulkheads have added centering pins for easier positioning on the chassis and for increased rigidity and consistency.

The new bulkheads offer an upper diff position that is higher than possible on previous models for improved handling in higher traction conditions resulting in better cornering speed and steering. The anti-roll bar mounting position keeps the wire bar placed under the drive shafts for a super low CG.

The bulkheads feature milled grooves for the ball bearing hubs so the bulkheads can sit 1mm closer to the chassis center line from each side.

The bulkheads are connected by a graphite brace in front and shock tower in rear for added stiffness.

Made from premium Swiss 7075 T6 aluminum, black anodized

The X4 motor and layshaft mounts are integrated into a one-piece design that is placed on the absolute center line of the chassis. The new motor mount has a pressed-in steel layshaft axle that is positioned in the middle of the chassis with the motor located to the rear of the layshaft. The motor mount is designed to maintain a super low CG but is still robust enough to resist bending in serious crashes. The more robust design also reinforces the center of the chassis and improves the stability of the X4.

The top of the motor mount features special milled holes to match the machined ultra-precise top deck screws made in-house. These purpose-made screws ensure the top deck is mounted completely tweak-free to improve the flex characteristics.

The motor mount features two integrated and adjustable belt tensioners to precisely set front and rear tension independently. The belt tensioners also serve as adjustable battery backstops.

The lower part of the motor mount features machined centering pins that are inserted in the chassis for easy assembly and to ensure it does not shift in a crash.

The X4 motor mount has two integrated and adjustable battery backstops to precisely set the battery offset from the center of the car. The battery backstop system is designed for use with the increasingly common shorty batteries as well as standard packs.

The battery backstops prevent the batteries from moving in a crash and interfering with the spur gear on the center layshaft.

For maximum drive train efficiency there are two ball-bearing equipped belt tensioners integrated in the motor mount’s battery backstop components. The two tensioners are individually adjustable to control the tension of the front and rear belts independently.

The motor mount is a vital part of the X4 Multi-Flex settings.

The X4 bulkheads have added centering pins for easier positioning on the chassis and for increased rigidity and consistency.

The new bulkheads offer an upper diff position that is higher than possible on previous models for improved handling in higher traction conditions resulting in better cornering speed and steering. The anti-roll bar mounting position keeps the wire bar placed under the drive shafts for a super low CG.

The bulkheads feature milled grooves for the ball bearing hubs so the bulkheads can sit 1mm closer to the chassis center line from each side.

The bulkheads are connected by a graphite brace in front and shock tower in rear for added stiffness.

Made from premium Swiss 7075 T6 aluminum, black anodized

The screws installed from the bottom of the caster inserts capture the inserts in the upper clamps to prevent them from coming loose while servicing the car. The screws also serve as the upper arms pivot ball mounts, reducing the number of components in the assembly and reducing weight.

The upper clamps and caster inserts are made from premium Swiss 7075 T6 aluminum and black anodized.

Aluminum inserts easily set the caster angle for quick and accurate tuning. The 2 dot inserts are included for both front and rear, with 1 and 3 dot inserts available for additional tuning options. In the rear suspension, the inserts can be reversed for even more adjustment possibilities.

The all-new Multi-Flex™ top deck has a narrow shape for easier installation, improved handling characteristics and features several different flex options out of the box through the use of a bearing and/or top deck screws.

The machined ultra-precise top deck screws ensure the top deck is mounted completely tweak-free to improve the flex characteristics.

Made from 2.0mm graphite material, the shape of the top deck has been specifically designed to achieve maximum traction and great steering characteristics at the same time.

The unique top deck flex settings allow quick and easy adjustment of chassis stiffness between a total of more than 10 different screw combinations. The well-proven bearing flex setting has been retained in the X4 top deck, along with 4 additional screw holes that utilizes special tweak-free flex screws for even more adjustability and fine tuning of the flex settings.

The front solid axle and rear differential feature updated designs to move the belt positions closer to the center. By moving the belts closer to the center line of the car, the forward traction and efficiency is greatly improved, which is beneficial in both stock and modified classes

The X4 gear diff produces the on-power steering that is needed on nearly all types of tracks, and is ideal for both carpet and asphalt tracks

The gear diff includes a composite case and cover with the integrated pulley. The internal gears are precision molded from tough composite material and combined with aluminum drive shaft adapters to create a light and super-smooth differential.

Another key advantage of the gear diff is that it is virtually maintenance-free. When the diff is correctly built, there is no need for maintenance for a very long time… no need for frequent oil changes, and no leakage due to the superior sealing system.

New solid axle features updated pulley position to shift the front belt alignment to match the new center layshaft for improved consistency and forward traction.

Precision-molded spur gears are made from XRAY's exclusive composite material, ensuring true running, super-quiet operation, and robustness for handling powerful motors. A range of optional spur gears for fine tuning is available.

The split aluminum front shock towers are mounted directly to the chassis and have adjustable flex options by adding screws to secure the towers to the bulkheads for additional stiffness.

All-new aluminum one-piece rear shock tower is mounted directly to the rear bulkheads and its shape provides optimized shock positions for maximum rear traction. Unlike the split front towers, the one-piece rear tower was found to provide better consistency and balance throughout testing.

All-new rear body mounting system is connected directly to the chassis and allows installation of the body posts in both the traditional vertical position and a horizontal position for a different feel on the track

The carbon fiber brackets are machined from strong 3mm thick material and are connected to the chassis via sleek aluminum mounts.

Universal reversible servo mount fits all standard servos without extra parts, with the choice of front or rear position to adjust the chassis flex and steering feel for different conditions.

The X4 features longer 58mm ECS drive shafts in the front and 54mm CVD aluminum drive shafts in the rear. Both ECS and CVD drive shafts have redesigned drive axles with new geometry that places the driveshaft pivot point in line with the rotation of the hubs for improved efficiency and cornering speed.

The XRAY ECS drive shafts equalize the speed between the drive shaft and the wheel when cornering. With a unique 2-piece joint between the driveshaft and the wheel, an extreme turning angle is divided into two shallower angles in the ECS assembly to prevent bind while rotating. Regardless of cornering speed and wheel angle, the inner wheel will not bind or vibrate when using the ECS. Movement through the corner is more stable and precise. With the ECS drive shafts, wheel vibrations and noise are decreased to a minimum, steering is increased, and cornering speed & smoothness are noticeably improved.

ECS drive shafts are exclusively manufactured from special self-developed HUDY Spring Steel™. The drive shafts are strategically lightened to guarantee the lowest possible weight without compromising strength or durability.

The 58mm ECS driveshafts improve performance right out of the box, increasing stability and cornering speed.

The rear of X4 features 54mm long lightweight aluminum CVD drive shafts machined from premium Swiss 7075 T6, hard-anodized and black-coated for stylish looks.  

The ECS BB (Ball-Bearing) driveshafts offer a significant performance gain over the standard blade-type driveshafts. The friction between the driveshaft and the outdrive is reduced, which helps to give a smoother handling feel, especially on fast direction changes, such as chicanes. The reduced friction helps to increase cornering speeds.

Drive shafts are exclusively manufactured from special world-renowned, top-secret, self-developed HUDY Spring Steel.

Maintenance of these bearing driveshafts is necessary, but very simple. Build them as you would your normal ECS driveshafts, but with the following addition; we recommend using the Hudy Joint Grease (106213) between the small bearings and the outdrives, for a prolonged life of the parts.

The aluminum front chassis brace installs underneath the front solid axle and significantly improves the front chassis stiffness, making the X4 steering more responsive and generating more forward traction. 

The graphite brace reduces flex in the front of the car. The brace will increase initial steering response but will reduce grip from mid corner to exit. The brace is recommended for any conditions that benefit from aggressive initial response and is more precise to drive. The brace also increases stability on bumpy tracks

The composite front upper bumper brace prevents chassis damage in serious crashes. The brace was designed to distribute the forces from a big impact to reduce damage to the chassis plate. There are two different mounting positions depending whether the graphite brace is installed or not.

All X4 kits include progressive 2.5-2.8 shock springs F/R that are a better starting point for most tracks.

The 4S springs - like all other XRAY springs - are manually measured, selected, and matched into pairs to guarantee precisely equal length and damping characteristics.

XRAY was the first company to introduce the SLP shocks that lowered the CG of the car. Since that time, SLP shocks became the industry standard that everyone uses.

With ongoing development and pushing performance boundaries, XRAY designed unique ULP (Ultra Low Profile) shocks which are 4mm shorter than SLP shocks, thus improving the stability of the car.

ULP shocks were developed to lower the CG of the car even more to the absolute lowest to further improve stability. With ULP shocks the X4 stays flatter, making it easier to drive in chicanes and making it more resistant to traction rolling, letting you carry more speed through high-traction sweepers. Steering response and cornering speed are significantly improved as well.

Shock bodies are CNC-machined from premium Swiss 7075 T6 aluminum and hardened to ensure maximum lifespan. The aluminum upper and lower nuts have a lower-profile design, including sealing O-ring and upper composite ball joint.

The well-proven pistons remain unchanged, and the set includes 3- and 4-hole pistons with 1.0, 1.1, and 1.2mm diameter holes. The pistons are molded using special processes and composites to ensure extreme roundness while maintaining maximum stiffness and durability.

The XRAY servo saver has become the industry-standard saver and remains unchanged and is included in each X4 kit.

Several linkage mounting positions are offered to make the steering linkage adjustment easier. The servo saver consists of 4 springs which makes the servo saver strong enough to provide the precise steering racers demand, while still being flexible enough to prevent servo damage in hard crashes. The servo saver has interchangeable bushings to fit most popular servos.

The system controls the positioning of the pack in the chassis while at the same time reducing the battery pack’s impact on chassis flex, resulting in more consistent handling and stability.

Smart battery holders are specifically designed for LiPo batteries and are reinforced for harder impacts. The battery holders prevent the batteries from moving under racing conditions and crashes.

To ensure maximum performance, the X4's high-precision pivot balls are machined in-house and then black coated or nickel coated for a smooth and long lasting finish. To maintain proper balance through every run, the in-house machined top deck screws ensure tweak free handling from start to finish.

The 2-belt 4WD drivetrain concept provides maximum efficiency featuring 3mm narrow front and rear drive belts that have been specially ground for minimal thickness and maximum flexibility.

A full set of 25 high-speed, blue-sealed and steel ball-bearings are used throughout the drivetrain, steering and anti-roll bars to ensure maximum efficiency. All of the bearings are degreased and oiled with Aero Shell® Fluid 12 for maximum smoothness and long life. The bearings used in steering blocks and uprights have been specially selected to reduce unsprung weight and maximize drivetrain efficiency.

Both front and rear bulkheads feature additional integrated belt-tension adjustment through the use of adjustable bearing eccentric holders. These holders are also reversible to move the differential height from the lower or upper position that is now +1mm higher than the T4 platform.

The wobble-free anti-roll bar system is mounted to the front & rear bulkheads via bearings for extra-smooth movement and quick & easy changes and adjustment. Each of the X4 versions comes with specifically chosen thickness of anti-roll bars for best possible performance out of the box.

X4 graphite edition features front 1.3mm and rear 1.2mm anti-roll bars.

X4 alu editions feature front 1.4mm and rear 1.3mm anti-roll bars.

The roll bar rotates in ball-bearings for maximum precision and free movement. Anti-roll bar height is adjustable via a screw.

The complete range of different anti-roll bar thicknesses is designed to work with the ball-bearing roll bar mounting system.

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 chassis features pre-drilled holes for additional weights for optimum car balancing and centerline holes for easy balancing with the HUDY Chassis Balancing Tool #107880.

The extensive and impressive range of adjustment possibilities includes: ARS (Active Rear Suspension™), caster, camber, toe, anti-dive, anti-squat, ride height, downstops, track-width, lower roll center, upper roll center, roll center positions, steering roll center, wheelbase, Ackermann, steering lock, bumpsteer, belt-tension adjustment, adjustable shocks, adjustable in-line flex adjustment, adjustable front chassis flex, diff height and adjustable diff.

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.

To get the finest tips & tricks on how to build the X4 or to learn more about each of the set-up options, follow the series of XRAY X4 Tech Tip videos featuring Alexander Hagberg. The videos walk through each section of the building process with suggested assembly techniques, demonstrations, and detailed explanations of the various setup adjustments.

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 Tech Talk groups. 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.