All-new Chassis.

The T4 features an all-new chassis specifically designed for all kinds of track conditions. The new 2.2mm thick chassis is CNC-machined from premium-grade graphite material and provides maximum traction under low traction conditions while maintaining stability and forgiveness under high traction conditions.
Weight distribution and balance characteristics have been enhanced. Due to the increase in LiPo capacity resulting in additional weight and heavier duty electronics to handle the increased power of modern brushless systems, the chassis was designed to allow the weight to move as close as possible to the chassis centerline in order to maintain balance.
In addition, the bulkhead mounting holes were narrowed by 6mm to make the mounting points as narrow as possible for more traction and better balance.

The front and rear portions of the chassis were strategically redesigned to provide maximum steering and traction.

The chassis is an ultra-narrow 94mm wide and features pre-drilled holes for options such as: chassis weights, graphite motor guard and battery strap.

All-new Top Deck.

New top deck has been redesigned for the new narrow bulkheads. The shape of the rear portion of the top deck has been specifically designed to achieve maximum traction and in corner steering. The top deck is machined from premium-grade 2.0mm graphite. An optional belt tensioner can be mounted to the top deck.

All-new Super Low Profile (SLP) Shocks.

T4 shock absorbers were completely redesigned and re-engineered. Everything is new and the shocks are aluminum.

The new SLP shocks were developed to lower the CG of the car to the absolute maximum in order to improve stability.

With the new SLP shocks the T4 stays flatter, making it easier to drive in chicanes and more resistant to traction roll, letting you carry more speed through high traction sweepers.
SLP shocks feature new shock caps, new shock collars, new pistons, as well as all new composite parts.

The shocks also feature bladders and foam inserts for smoother shock operation.

Shock rods have been specially hardened to ensure long life and maximum strength.
To accommodate the all-new Super Low Profile (SLP) shock absorbers the all-new pistons were designed and produced.

The set of pistons include 3 and 4 hole pistons with 1.0, 1.1, and 1.2mm diameter holes. The pistons are molded using special methods and composites to ensure extreme roundness, while maintaining maximum stiffness and durability.
The new Super Low Profile (SLP) shocks are almost 8mm shorter compared to the shocks on the T3.

The shock bodies are CNC-machined from premium Swiss 7075 T6 aluminum and hardened to ensure maximum life.

The shocks consist of a shortened shock body but with a larger diameter to retain the same volume of oil as the previous, longer T3 shocks.

Both front are rear shock absorbers have front and lower ball joints by purpose larger to provide a little of play of the shocks once mounted to generate more traction.

All-new Super Short Shock Springs (4S).

The all-new 4S springs have been specifically designed to complement the SLP shocks and are 5mm shorter than previous XRAY springs.

The T4 comes equipped with C2.7 linear springs in the front to provide maximum stability and steering and C2.3-2.6 progressive springs in the rear to provide maximum traction and cornering speed.

The main advantage and benefit of progressive springs is that as the car initially enters the corner they work like a C2.3 spring to provide maximum traction. At the same time, when the chassis begins to roll, in the middle of the corner, the spring rate progressively increases until it works like a C2.6 which allows the car to maintain maximum cornering speed.

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

All-new Shock Towers.

To maximize the effect of the new SLP shocks, both front and rear shock towers were completely redesigned and lowered by 15mm to help move the CG as low as possible. Machined from premium-grade 3.0mm graphite, the shock towers are smaller, lighter, more compact and, after vigorous testing, have been race-tuned to increase on-power steering.

All-new Aluminum Bulkheads.

To accommodate the ultra-low design of the T4 platform with centralized weight placement, all the bulkheads were completely redesigned.

The smallest and lightest bulkheads ever are positioned more to the chassis centerline to provide maximum traction, steering and balance.

All bulkhead parts are CNC-machined from premium Swiss 7075 T6 aluminum and have been designed to provide the lightest and strongest possible support framework for the car.
All 4 differential bulkheads now share a common design in order to reduce spare parts requirements and increase parts compatibility. The left and right layshaft bulkheads also share a common design and are interchangeable with one another.

The bulkheads are anodized in a distinctive orange color. (Note: Color may vary slightly between products.) XRAY’s legendary attention to detail is noticeable in all the precisely chamfered edges.

All-new Motor Mount.

The all-new motor mount has been isolated from the layshaft bulkhead in order to eliminate unwanted tweak.

The motor mount is fixed to the bulkhead by two screws and to the chassis via M3 nut providing the tweak free platform.

Thanks to this unique design the motor mount has been moved 3mm closer to the chassis centerline, which increases stability and improve balance of the car.

The motor mount is CNC-machined from premium Swiss 7075 T6 aluminum.

All-new Upper Bulkhead Clamps.

To coincide with the new super narrow bulkheads, the upper bulkhead clamps were also redesigned. With 3 different roll center mounting positions, adjusting the roll center of the chassis is quick and easy.

The clamp height has been reduced by 2mm compared to the previous platform, which adds additional flexibility for roll center adjustments by allowing you to add or remove shims under the ball studs.

In order to keep the same well-proven roll center geometry the roll center positions have been moved outside to offset
the new narrow
bulkhead design.

All-new Bearing Holders.

The adjustable bearing eccentric holders were also updated to mate with the new, narrower bulkheads. As with previous XRAY designs, both front and rear bulkheads feature integrated belt-tension adjustment through the use of adjustable bearing eccentric holders, eliminating the need for a separate belt tensioner while reducing friction and improving drivetrain efficiency.

All-new Suspension Mounts.

The front and rear suspension holders are CNC-machined from premium Swiss 7075 T6 and are fully independent from the bulkheads and mounted directly to the chassis which increases traction and makes the car easier to drive.

The front one piece holder has been updated to allow easier access to the steering rack to simplify Ackermann adjustment.

The all-new reinforced rear aluminum lower suspension holders are mounted to the chassis with two screws for extra strength and have been moved 0.75mm inboard to narrow the rear track width and provide more in corner steering. The holders are pre to give integrated toe-in.

All-new Central Servo Mount.

XRAY’s own invented and designed central servo mount is now a standard in the T4.

This new style mount allows the servo to be mounted to the chassis without the servo coming into contact with the chassis plate. This design has beent engineered to eliminate tweak and increase overall traction.
The Swiss 7075 T6 main aluminum stand is positioned along the chassis centerline for perfectly balanced flex characteristics and holds the high-grade graphite servo plate suspended above the chassis.

All-new Steering Plate.

To gain more steering and to improve the direction changes of the car, the steering plate was redesigned to move the connection of the servo linkage into the absolute center of the dual arm steering system and is CNC-machined from premium Swiss 7075 T6 aluminum.

The steering plate also works as a mechanical stop for the steering throw, limiting the steering angle to 25 degrees in order to smooth steering response and maintain maximum corner speed.

New Servo Saver.

The popular XRAY servo saver was improved and updated for the T4. To make the steering linkage adjustment easier additional positions on the servo saver were added. The servo saver consists of 4 springs which makes the servo saver strong enough to provide the precision steering racers demand, while at the same time being flexible enough to prevent servo damage in hard crashes. The servo saver has interchangeable bushings to fit most popular servos.

All-new Anti-Roll Bars.

To accommodate the narrowed front and rear bulkheads, all-new anti-roll bars were designed. Front 1.4mm and rear 1.2mm anti-roll bars are included in the kit, and a full line of optional anti-roll bars for super-fine tuning is available.

For easy recognition the anti-roll bars have laser-engraved stripes (to indicate bar thickness) for easy and instant recognition.

The anti-roll bars are mounted using the included composite holders on the front and rear bulkheads, and to the integrated anti-roll bar mounts on the suspension arms. The rear anti-roll bar mounting location was updated on the T4 and is now in a horizontal position for easier accessibility.

New Rear Uprights.

To improve the stability of the car and to increase cornering speed of the T4 the hard "H" rear uprights are included.

The rear uprights feature 0° toe to ensure stability and prevent suspension geometry changes in hard crashes. There are two different roll center positions on the rear uprights, and more roll center positions can be easily adjusted by adding shims between the upright and the turnbuckle ball joint.

The rear uprights feature small but robust 5x10x4 ball-bearings to minimize unsprung weight.

The rear uprights are available in two different material formulations that were specifically blended for particular racing conditions. Available in medium “M” hardness as an option.

1-hole uprights were developed as an optional fine-tuning part to compliment the standard 2-hole uprights for high-traction tracks where more roll of the car is desired.

These 1-hole uprights provide an additional option versus the standard 2-hole upright when the outer hole does not allow enough roll, and the inner hole creates too much roll.

50mm Rear Drive Shafts.

The T4 features 50mm long lightweight aluminum drive shafts machined from premium Swiss 7075 T6, hard-anodized and black coated for stylish looks. The aluminum drive shafts are designed for use in the rear.

All-new Bumper.

To improve the body fit as well to lower the CG an all-new front from bumper was designed which is 1/3 lower and lighter and manufactured from highly resilient lightweight foam.

The lower composite bumper mount and upper bumper holder are molded from rigid composite material to withstand heavy impacts.

An optional stiffer foam bumper (#301225) as well as an impact-absorbing lower bumper mount (#301203) are available as option parts.

XRAY Gear Differential.

The T4 gear diff increases on-power steering which 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 pulley. Differential gears are made from tough composite material, precision-molded composite gears combined with light aluminum drive shafts, which create a lighter and super-smooth gear differential.

Another key advantage of the gear diff is that it is 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.

XRAY Solid Axle.

Rotating mass is one of the most significant influences on the performance of an RC racecar. The T4 features a unique lightweight composite XRAY Front Solid Axle.

The Front Solid Axle has a very stiff and ultra-light weight structure that was achieved by molding the entire solid axle from XRAY’s own self-formulated composite material.

Outdrives are fully exchangeable which allows very easy and comfortable servicing, while the unique drive shaft connection — eliminating the former drive shaft blades — enables direct power transfer to the axle and eliminates play between the drive shaft and outdrives, improving steering precision and increasing overall steering.


The ultra-efficient and well-proven drive train has been carried over from the T3 platform. The drive ratio is fully suitable for the current high performance brushless motors (both stock and mod) and LiPo batteries. Both the front solid axle and the rear gear diff feature 38T pulleys and the central layshaft features 20T pulleys for an efficient internal ratio of 1.9.

Integrated Belt Tension Adjustment.

As with previous XRAY cars, both front and rear bulkheads feature integrated belt-tension adjustment through the use of adjustable bearing eccentric holders, eliminating the need for a separate belt tensioner. These eccentric holders were modified to fit the new super narrow position of the bulkheads, while allowing you to still use your existing differentials and spools. All ball-bearings turn in composite hubs to reduce friction and improve drivetrain efficiency.

Diff Height Adjustment.

Both front and rear bulkheads feature independent diff height adjustment. By rotating the diff eccentric holders, the height of the diff can be adjusted by 1mm. Optional eccentric holders with 2mm offset are available which allows diff height adjustment of 2mm.

Centrally-positioned Layshaft.

The spur and pinion gears have been aligned along the absolute centerline of the chassis to optimize the placement of the polar moment and ensuring ideal balance of the drivetrain components.

Alu Middle Layshaft.

The aluminum layshaft is strategically CNC-machined to minimize rotating weight without compromising strength or integrity.

The hollow layshaft is perfectly round with zero run out, eliminating drivetrain vibration and producing a positive balance.

Composite pulleys key solidly to the layshaft.

Premium Ball-Bearings.

A full set of 20 high-speed, blue-sealed ball-bearings are used throughout the drivetrain 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.

Kevlar® Drive Belts.

The 2-belt 4WD drivetrain concept provides maximum efficiency and highest performance using Kevlar®-reinforced drive belts for ultra-high durability.

Narrow (3mm) front and rear drive belts have been ground to minimize thickness and flexibility.

HUDY Spring Steel™ CVDs.

T4 constant velocity drives (CVDs) are exclusively manufactured from special world-renowned, top-secret, self-developed HUDY Spring Steel™. The drive shafts are the world‘s tiniest yet most durable drive shafts used in electric touring cars.
The drive shafts are strategically lightened – see the hollow end of the dog bone – to guarantee the lowest possible weight without compromising strength or durability. These specially-lightened drive shafts can only be manufactured from special HUDY Spring Steel™ which was developed for extreme racing conditions. The drive shafts have been additionally hand-ground for maximum precision and to provide true rotation and unbinding drivetrain operation.

Super-lightweight Drive Axles.

To reduce rotating weight, the T4 features super-lightweight wheel axles which have the outer diameter specially ground to remove the material while keeping the same strength thanks to the use of HUDY Spring Steel™ material. The lightweight drive axles reduce rotating mass up to 35% compared to regular drive axles.

Suspension Holders.

The T4 uses the same smart suspension holders as the T3 platform. The aluminum inserts in the composite holders guarantee that geometry and setup will not change and will be retained even after hard crashes.

There are 3 different suspension composite holders that enable easy roll center setup. The standard suspension holder gives a 0mm roll center, while two eccentric suspension holders raise or lower the roll center by 0.75mm.

The independent suspension holders of the T4 allow for even more precise roll center adjustment. The suspension holders — which are mounted on separate bulkheads — may be shimmed outward from the bulkheads (using 0.1–0.5mm shims) for precise roll center positioning.

The smart XRAY geometry uses variable-thickness shims between the bulkheads and suspension holders to enable easy rear toe-in adjustment. However, you can easily remove the shims which will narrow the suspension, and then add wheel offset shims to reclaim track-width.

Proven Suspension Geometry.

From the narrow arms, through the tiny front and rear suspension blocks, to the small and robust steering blocks, every suspension part has been specially designed to provide responsive racing characteristics in all racing conditions.

Over the years XRAY has successfully gained and utilized extensive suspension geometry knowledge and self-developed suspension stiffness technology, which have been utilized when designing suspension parts. The ultra-lightweight suspension parts are molded from a special composite material that makes the parts very light yet very durable to withstand the rigors of high-performance racing.

The T4 platform features optimized suspension parts carried over from the T3platform. The arms feature a single optimized shock mounting position and integrated anti-roll bar mounts. The rear arms feature three anti-roll bar mounts for super-fine adjustment of the anti-roll bar.


The C-hubs in the T4 are also carried over from the T3 platform and feature large openings for quicker & easier assembly/disassembly of the CVDs.

The entire CVD assembly can be easily inserted/removed through the C-hub without the need for disassembly. The large openings prevent collision of CVD with C-hub in serious crashes and are optimized for use with optional ECS drive shafts.

The C-hubs are available in all standard caster angles (2°, 4°, 6°) and are also available in two different hardnesses that are optimized for particular racing conditions.

Steering Blocks.

The small and tough steering blocks each feature two Ackermann positions. The front steering blocks also feature small but robust 5x10 ball-bearings to minimize unsprung weight.

The steering blocks are available in two different hardnesses, which are optimized for particular racing conditions.

Dual Arm Steering System.

The dual arm steering system is supported by 6 ball bearings and runs on aluminum stands. Ackermann is easily adjusted by inserting shims between the steering plate and steering rods.

The new steering system features a lower mounting position for steering linkage which makes the car handle easier going into corners. Handling is easily adjusted for more aggression by inserting a shim between the steering block and steering rods.

The front lower suspension holder has been updated to allow easier access from the front of the car for quick and easy Ackermann adjustment.

Alu Hex Hubs.

Ultra-lightweight wheel hex drive hubs are CNC-machined from 7075 T6 black-coated aluminum. These ultra-true hex hubs are specially machined to reduce rotating weight while guaranteeing wobble-free wheel mounting. Optional offsets are available (-0.75, +0.75, +1.5mm).

Aluminum Turnbuckles.

Aluminum adjustable turnbuckles used in the T4 are CNC-machined from 7075 T6 material with a stylish black coating. These turnbuckles are used for front and rear upright linkages as well as for the servo saver. The aluminum turnbuckles are lighter than steel to help decrease the overall weight of the car.

Body Posts.

Beefy 6mm thick body posts are made from special composite material that provides maximum strength but sufficient flex to reduce body post breakage in hard crashes or if you flip the car over. The body supports are rounded to have a better fit and provide better support to the car body.

For ultimate tuning and adjustment, XRAY offers optional body height adjustable body posts which allow the independent front & rear body height adjustment by +1mm or +2mm.

Battery Holders.

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

Adjustment Possibilities.

The extensive and impressive range of adjustment possibilities includes: 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, optional belt-tension adjustment, adjustable shocks, adjustable rear diff and adjustable optional front XRAY Multi-Diff™.

Chassis Balance.

The chassis design focuses on balanced weight distribution and weight transfer. The chassis features pre-drilled holes for additional weights for optimum car balancing. Centerline holes are pre-drilled for easy balancing with the HUDY Chassis Balancing Tool #107880.

Graphite Grease.

The T4 includes premium 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 Set-up Book.

The new T4 retains the title of the most adjustable electric touring car in the world. Whether you are a hardcore racing fanatic or a club-level sportsman, you can very easily adjust the T4 to suit your racing style, race track type, and all track conditions. The T4 features the legendary XRAY Set-up book, loaded with over 50 pages of high-quality picture and easy-to-read RC car set-up explanations. Whether you are a novice driver or an 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 T4. The T4 set-up book is available for download exclusively at www.hudy.net.

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.

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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