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.

The all-new chassis has been significantly narrowed and reconfigured to match the new bulkheads and lower arms, and integrate with the new one-piece aluminum servo & steering mount and the new forward motor mount position, moving the mount 5mm to the front to generate more traction.

The chassis has been narrowed 5mm in the front, and 10mm in the rear for improved flex that improves steering and rotation while also reducing chassis drag for improved cornering speed.

The new motor mount has been repositioned 5mm further forward for more traction. The clamping screw is moved closer to the motor to create space for the new steering arm.
The motor mount and its slick low-profile design eliminates top deck collisions during chassis flex. The motor mount features 3mm centering pins for exceptional 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.

All-new one-piece servo mount moves the servo 5mm more forward for improved traction. The single steering arm saves weight. The servo mount works as part of the battery holder system that moves the battery forward for better traction.

 The one piece design of the servo mount eliminates servo movement in serious crashes. The servo mount features an ultra-low design to save weight, and to lower CG as much as possible.

The X4F’25 is 25g lighter than X4F’24. The rear suspension has been strategically lightened to move the weight maximum frontwards. Additionally, all the electronics have been moved 5mm forward for maximum front traction.

Thanks to the lighter design, racers have greater weight distribution set-up options for easier adaptation to different track conditions.

All-new steering arm was simplified from 6 components into 1 single component for additional weight savings. 

The included 100g weight can be placed in the bumper for improved traction in lower traction conditions. For high traction conditions, optional 50g weights can be placed under the front drive train.

The bumper is made from a harder and heavier material, improving durability and weight balance. The bumper is shaped with space for the front chassis weight.

With the BPA (Body Position Adjustment) system, the entire bumper area was redesigned with upper & lower composite bumpers. The foam bumper design works with the adjustable eccentric body posts as well as the standard fixed body posts.

The all-new rear bulkheads contribute additional weight savings.

The bulkheads feature a higher ARS link mounting position allowing greater adjustment possibilities, the horizontal orientation allows moving the ARS link frontwards or backwards to alter rotation characteristics.

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

The anti-roll bar mounting position keeps the wire bar placed under the drive shafts for a super low CG.

All-new graphite rear upper arm holder replaces the previous aluminum pieces to reduce weight. The holder is one of many rear suspension components that were strategically lightened to shift the weight balance forward.
The most frequently used alu caster bushings are now included in the kit for the maximum performance right out of the box.

The upper arm holder uses caster inserts for quick and easy set-up changes. The screws installed from the bottom of the caster inserts capture the inserts in the upper arm holder 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 arm holder is made from premium graphite material. The caster inserts are made from a premium 7075 T6 aluminum material.

The extra thick 4mm graphite rear body post holder improves durability and stability from the reduced body post flex.

The body post holder features 6 holes with 1.4mm spacing for the rear body posts plus a second bulkhead mounting position between the 1.1mm spacing for easier and more precise mounting of the included horizontal rear body posts.

All-new solid composite upper arms have increased flex that generates more traction, beneficial for FWD in most conditions. The added flexibility  provides improved durability in serious crashes as well.
The new upper arm shape conforms around the shock position for proper clearance without compromising strength, and improves forward traction along with lateral grip and steering. The updated design also improves durability and eliminates radial play for maximum precision and control from the upper arms.

All-new top decks match the new layshaft position. The rear top deck now uses only one pair of mounting screws for increased flex, resulting in improved rotation.

The front top deck is now without the cut-out to improve steering precision .

The 2pc top deck features reinforced motor mount screw areas for high durability, improved steering and traction.

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 8 different flex options.

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

All-new battery mounting system is integrated with the new servo mount, allowing the battery to move as far forward as possible to improve traction.

The tweak-free, fully adjustable Quick Battery Mounting System offers simple and secure battery installation without tape and without adverse effects on chassis flex.

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.

The battery holder is integrated into the servo mount. In the rear the battery holder is mounted to the chassis and is adjustable in all directions.

Medium composite hubs improve traction and steering characteristics..

The composite 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 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.

The completely redesigned upper & lower CFF™ suspension arms are the foundation for the new inner shock mounting system ultra-low under arm anti-roll bar mounts and fully updated geometry. The new suspension arms greatly improve flex and twist under dampening. With the shock mounted on the inside of the arm, the load is more evenly distributed through the suspension arm, increasing the mechanical traction and responsiveness of the car.

The re-designed location lowers the shock 4.5mm to reduce the CG and improves cornering speed and stability. These changes make the new X4F easier to drive and more resistant to traction rolling in high traction conditions.

1.0mm shims for mounting under the front lower arms are now included to lower the front roll center and improve steering.

The CFF™ style of arms provide extremely responsive and sharp handling, generating great cornering speed & traction. The result is great drivability that is critical for improved lap times.

All-new inner shock mounting locations improve the rolling characteristics & cornering consistency, as well as optimize flex and reducing twist under dampening. Front suspension moves the shock position behind the drive shafts for more precise steering response and improved steering characteristics. Rear suspension moves the shock position in front of the rear axles for improved traction.

Versatile new shock holders use shims for adjusting the shock position in more precise shock angle increments. The rear shock holder offers an Active or Fixed dampening setting in addition to the shock angle. All shocks are located 4.5mm lower, improving CG, cornering speed and stability, while also making the car easier to drive and more resistant to traction rolling.

Simplified shock mounting uses a captured mounting stud secured to the shock holder with a special setscrew. It is not necessary to use thread lock as the setscrew will keep the stud secure even during shock install/removal.

Updated front & rear steering plates work with the new arms and shock positions.

The new steering plates are redesigned to work with the single steering arm that makes the X4F`25 easier to drive and improve steering response.

The ARS plates move the toe link mounting position further forward for improved rotation in high traction conditions.

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

The counter sunk screw mounted from the bottom allow easy bump steer / toe gain adjustment.

Our unique ECS system uses a redesigned drive shaft case with a C clip groove to secure the new aluminum pin retainer.

Thanks to this unique SCS – Spring Clip System, no set screws are needed to capture the coupler pins, making the ECS assemblies easier and more convenient to assemble, and more reliable.

The driveshaft service life is increased as the pins float freely in the joints, ensuring smoother rotation and improved cornering speed.

BB drive shafts improve speed & rotation and are included in the kit and feature a 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 ultra-low CG anti-roll bars are attached from below the suspension arms with considerably reduced mounting hardware and material.

The wobble-free anti-roll bar height is easily & comfortably adjusted via set screw from the top of the arm.

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.

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

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

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

The 9mm shorter XLP Shocks are 10.4g lighter in total yet contain the same oil volume as the ULP shocks for improved cornering speed, steering response, and stability.

The XLP shocks make the car easier to drive in all conditions and surfaces. The shocks are each 2.6g lighter, shaving 10.4g off the weight in front and behind the transmission.

The shorter shocks lower the CG to further improve stability. With the shorter shocks, the car 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.

The 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 XLP shocks, so existing PSS tuning options can be used.

All of the 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 XLP 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/X4F  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.

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 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.

The wheel hubs work with the SCS - Spring Clip System for simplified installation. The wheel hubs are 0.5mm narrower than the original X4F hexes to reduce the car’s track width, to increase steering and traction.

The ultra-narrow wheel hubs are lightened for reduced rotating mass.

The kit includes 6.5mm pivot balls for different rear hub height adjustments. The 6.5mm long pivot balls 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.

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 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.

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 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.