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 X4F is truly a masterpiece.

X4F is designed and based on the X4 platform and as such majority of parts are fully compatible.

All-new carbon chassis has 2mm shorter wheelbase in rear for improved steering and traction characteristics. The new chassis has redesigned holes placement for thicker motor mount pins that increase durability. The servo mount’s more forward position improves pinion gear clearance and weight balance.

The new motor mount and its slick lower profile design eliminates top deck collisions during chassis flex. The motor mount features 3mm centering pins for improved crash durability when using only one mounting screw.

The X4F motor and layshaft mounts are integrated into a one-piece design that is placed on the absolute center line of the chassis. The motor mount has a pressed-in steel layshaft axle with the motor located to the front 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 robust design reinforces the chassis and improves the stability of the X4F.

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.

An aluminum eccentric bulkhead insert is accessible through a cutout in the mount and is adjusted from the top for easier gear mesh adjustment.

Machined from premium Swiss 7075 T6 aluminum and black anodized.

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The narrower motor bulkhead insert moves the motor 1mm further inward improving the roll characteristics.  The new motor bulkhead inserts also allow for more space for pinion mounting.

All-new XLP Shocks are 9mm shorter and in total 10.4g lighter but contain the same oil volume as the ULP shocks for improved cornering speed, steering response, and stability.
The new shocks make the car easier to drive in all conditions and surfaces. The shocks are each 2.6g lighter, which helps to save 10.4g off the weight in front and behind the transmission.

The new shorter shocks lower the CG to further improve stability. With the shorter shocks, the X4’23 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.

A new membrane shape and material improves maintenance. The membranes can be used for a very long time without any changes to the rebound setting.

In spite of the shorter overall length, the PSS inserts for the ULP shocks are compatible with the new X4’23 shocks, so existing PSS tuning options can be used.

All of the new XLP shock parts are specifically designed for the smallest possible size to reduce the weight and keep the lowest possible CG.

Shock bodies are CNC-machined from premium Swiss 7075 T6 aluminum and hardened to ensure the maximum lifespan. The aluminum upper and lower nuts have a lower-profile design, including sealing O-ring and upper composite ball joint. The shock shaft, shock adjustable nut, spring retainer and pivot balls are redesigned as well to achieve the lowest shock height possible.

The included shock pistons sets are new 4-hole pistons with 1.1 and 1.2mm diameter holes. The pistons are molded using a special process and composites to ensure extreme roundness while maintaining maximum stiffness and durability.

The XLP series of springs are 3mm shorter to match the new shock length and provide the correct rates and ride height. They are available in a full range of rate choices including 2 new alternatives of the progressive springs C2.4-2.7 and C2.6-2.9.

The X4 stock shock springs offer versatile out of box performance for many conditions. The most popular C2.5-2.8 in front and C2.6 in rear are included in the kit.

All XRAY springs are manually measured, selected, and matched into pairs to guarantee precisely equal length and damping characteristics.

Front shock towers are redesigned for the shorter XLP shocks. They are 8mm lower to improve the CG with only two optimized shock mounting positions, upper position for carpet and lower position for asphalt.

The top mounting position is the best choice for carpet, with the lower position best suited for asphalt. 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.

The new rear shock tower is also redesigned to match the shorter XLP shocks. The shock tower is 8mm lower to improve the CG with only two optimized shock mounting positions, upper position for carpet and lower position for asphalt.

The shock tower is reworked for improved durability in hard crashes, with 1mm of added material to the thinnest part of the tower for added strength.

Unlike the split front towers, the one-piece aluminum rear tower is mounted directly across the rear bulkheads as this configuration was found to provide better consistency and balance throughout testing, and maximize rear traction.

Heavy duty lower bulkheads provide improved durability while maintaining ultra-low weight. The bulkheads have added material in the most critical area for improved strength; even stronger than the optional HD bulkheads.

The bulkheads use centering pins for easier positioning on the chassis and for increased rigidity and consistency.

The bulkheads feature two solid axle/diff height positions that were developed for different surfaces. The lower position is mainly designed for carpet, and the upper position is more common on asphalt. The anti-roll bar mounting position keeps the wire bar placed under the drive shafts for a super low CG.

The bulkheads have 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.

Heavy duty upper clamps provide improved durability in hard crashes. The upper clamps have added material in the most critical area for improved strength; even stronger than the optional HD upper clamps.

The upper clamps use caster inserts for quick and easy set-up changes, and use centering pins for precise installation and improved reliability in a crash.

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.

BB drive shafts improve speed & rotation and are now included in the kit and feature the all-new clip wheel hub retention system included for maximum comfort.

The X4F features 58mm ECS drive shafts with geometry that places the drive axle pivot point in line with the rotation of the hubs for maximum 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 traditional 3.5mm driveshaft caps are replaced by the BB adapters that reduce friction during suspension travel and driveshaft movement, resulting in improved cornering speed and rotation. The BB driveshafts are now standard both in front and rear.

The gear differential includes steel diff outdrives for the BB drive shafts. The 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 an 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 wheel hubs work with the new SCS - Spring Clip System for simplified installation. The wheel hubs are 0.5mm narrower than the original hexes to reduce the car width and increase steering and traction.

Graphite composite hubs provide improved geometry for better steering and traction, fully adjustable axle height and improved driveshaft alignment.

Graphite composite front and rear hubs provide the proper suspension geometry for improved steering and traction. The hubs contain small size bearings and a drive axle that moves the driveshaft pivot point deep into the hub, in line with the hub’s rotational axis between the upper and lower arm.  This alignment improves driveline efficiency and handling. 
The ultra-narrow wheel hubs are lightened for reduced rotating mass.

The hubs allow full adjustability of the axle height to adapt the car to every condition.

The design of the hub is universal with the same part used at all four corners with corresponding extensions. The aluminum front steering plates and rear ARS plates are easily mounted depending on the hub’s location.

New heavy duty steering plates and ARS plates provide improved durability in hard crashes. The new 3D shape allows using a low downstop without touching the lower arm at full steering lock.

The new counter sunk screw mounted from the bottom allow easier bump steer / toe gain adjustment. Plus, when changing the bump steer shims the length of the ball ends does not have to be changed anymore.

The kit includes new 6.5mm pivot ball for different rear hub height adjustments. The new 6.5mm long pivot ball with 1mm extra thread length is suggested when using more than a 0.5mm hub height shim to improve the durability of the rear hub in serious crashes.

New heavy duty rear graphite post holder provides increased durability in hard crashes and more precise height adjustability with preset 6 steps of 1.2mm increments. The redesigned shape eliminates collision with anti-roll bars.

Rear body mount system connects directly to the chassis for improved downforce and traction. 

New 2pcs top deck with reinforced motor mount screw areas for higher durability improve steering and traction. The included solid front top deck without cut-out improves steering characteristics with better corner apex transitions and improves durability.

The Multi-Flex™ top deck has a narrow shape for easier installation, improved handling characteristics and features several different flex options out of the box using 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. Optional one-piece top deck features 3 different flex options.

The top deck flex settings allow quick and easy adjustment of chassis stiffness in 2 different alternatives.

The X4F comes with specifically chosen anti-roll bars for the best possible performance out of the box. The rear 1.4 anti-roll bar improves cornering speed and keeps the car flatter through chicanes.

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 the X4F comes with specifically chosen thickness of anti-roll bars for best possible performance out of the box.

X4F features front 1.3mm and rear 1.4mm 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.

Anti-roll bars have laser-engraved stripes (corresponding to bar thickness) for easy identification.

New servo mount with two centering pins and two screws for graphite floating servo holder eliminates servo movement during hard crashes. Redesigned servo mounting system with a bit more frontward servo position provides better weight balance and improves clearance between servo and pinion.

Composite steering blocks and rear uprights are now moulded from hard composite mixture for improved traction and steering characteristics.

CFF front upper arms are now moulded from soft composite mixture for improved traction and steering characteristics.

Optional medium hardness is available to tune the handling to different track conditions.

New 2x50g chassis brass weights relocated under the front driveshafts along the centerline of the front suspension improve on/off-power weight transfer for better balance and rotation.

Some information shown below may include details from previous kits, and it may vary slightly from current kit specifications.

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.

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 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.

The XRAY servo saver has become the industry-standard saver and remains unchanged and is included in each X4F 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.

To ensure maximum performance, the X4F'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.

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.

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 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.

To get the finest tips & tricks on how to build the X4F or to learn more about each of the set-up options, follow the series of XRAY X4 Tech Tip videos featuring Alexander Hagberg and Stefan Schulz. The videos walk through each section of the building process with suggested assembly techniques, demonstrations, and detailed explanations of the various setup adjustments.

Please note that the videos are made specifically for the X4, but will contain very good information that may apply to the X4F as well.

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.