Xray X4 User manual

2
BEFORE YOU START
This is a high-competition, high-quality RC car intended for persons aged 16
years and older with previous experience building and operating RC model
racing cars. This is not a toy; it is a precision racing model. This model racing
car is not intended for use by beginners, inexperienced customers, or by
children without direct supervision of a responsible, knowledgeable adult. If
you do not fulfill these requirements, please return the kit in unused and
unassembled form back to the shop where you have purchased it.
Before building and operating your XRAY, YOU MUST read through all of the
operating instructions and instruction manual and fully understand them to
get the maximum enjoyment and prevent unnecessary damage.
Read carefully and fully understand the instructions before beginning assembly.
Make sure you review this entire manual, download and use set-up book from
the web, and examine all details carefully. If for some reason you decide this is
not what you wanted or expected, do not continue any further. Your hobby dealer
can not accept your kit for return or exchange after it has been partially or fully
assembled.
Contents of the box may differ from pictures. In line with our policy of continuous
product development, the exact specifications of the kit may vary without prior
notice.
SAFETY PRECAUTIONS
Contains:
LEAD (CAS 7439-92-1) ANTIMONY (CAS 7440-36-0)
WARNING: This product contains a chemical known to the state of California
to cause cancer and birth defects or other reproductive harm.
CAUTION: CANCER HAZARD
Contains lead, a listed carcinogen. Lead is harmful if ingested. Wash
thoroughly after using. DO NOT use product while eating, drinking or using
tobacco products. May cause chronic effects to gastrointestinal tract, CNS,
kidneys, and blood. MAY CAUSE BIRTH DEFECTS.
When building, using and/or operating this model always wear protective
glasses and gloves.
Take appropriate safety precautions prior to operating this model. You are
responsible for this model‘s assembly and safe operation! Please read the
instruction manual before building and operating this model and follow all
safety precautions. Always keep the instruction manual at hand for quick
reference, even after completing the assembly. Use only genuine and original
authentic XRAY parts for maximum performance. Using any third party parts
on this model will void guaranty immediately.
Improper operation may cause personal and/or property damage. XRAY
and its distributors have no control over damage resulting from shipping,
improper construction, or improper usage. XRAY assumes and accepts no
responsibility for personal and/or property damages resulting from the use
of improper building materials, equipment and operations. By purchasing
any item produced by XRAY, the buyer expressly warrants that he/she is in
compliance with all applicable federal, state and local laws and regulation
regarding the purchase, ownership and use of the item. The buyer expressly
agrees to indemnify and hold harmless XRAY for all claims resulting directly
or indirectly from the purchase, ownership or use of the product. By the act
of assembling or operating this product, the user accepts all resulting liability.
If the buyer is not prepared to accept this liability, then he/she should return
this kit in new, unassembled, and unused condition to the place of purchase.
IMPORTANT NOTES – GENERAL
• This product is not suitable for children under 16 years of age without the
direct supervision of a responsible and knowledgeable adult.
• Carefully read all manufacturers warnings and cautions for any parts used
in the construction and use of your model.
• Assemble this kit only in places away from the reach of very small children.
• First-time builders and users should seek advice from people who have
building experience in order to assemble the model correctly and to allow
the model to reach its performance potential.
• Exercise care when using tools and sharp instruments.
• Take care when building, as some parts may have sharp edges.
• Keep small parts out of reach of small children. Children must not be
allowed to put any parts in their mouth, or pull vinyl bag over their head.
• Read and follow instructions supplied with paints and/or cement, if used
(not included in kit).
• Immediately after using your model, do NOT touch equipment on the
model such as the motor and speed controller, because they generate high
temperatures. You may seriously burn yourself seriously touching them.
• Follow the operating instructions for the radio equipment at all times.
• Do not put fingers or any objects inside rotating and moving parts, as this
may cause damage or serious injury as your finger, hair, clothes, etc. may
get caught.
• Be sure that your operating frequency is clear before turning on or running
your model, and never share the same frequency with somebody else at the
same time. Ensure that others are aware of the operating frequency you
are using and when you are using it.
• Use a transmitter designed for ground use with RC cars. Make sure that no
one else is using the same frequency as yours in your operating area. Using
the same frequency at the same time, whether it is driving, flying or sailing,
can cause loss of control of the RC model, resulting in a serious accident.
• Always turn on your transmitter before you turn on the receiver in the car.
Always turn off the receiver before turning your transmitter off.
• Keep the wheels of the model off the ground when checking the operation
of the radio equipment.
• Disconnect the battery pack before storing your model.
• When learning to operate your model, go to an area that has no obstacles
that can damage your model if your model suffers a collision.
• Remove any sand, mud, dirt, grass or water before putting your model
away.
• If the model behaves strangely, immediately stop the model, check and
clear the problem.
• To prevent any serious personal injury and/or damage to property, be
responsible when operating all remote controlled models.
• The model car is not intended for use on public places and roads or areas
where its operation can conflict with or disrupt pedestrian or vehicular traffic.
• Because the model car is controlled by radio, it is subject to radio
interference from many sources that are beyond your control. Since radio
interference can cause momentary loss of control, always allow a safety
margin in all directions around the model in order to prevent collisions.
• Do not use your model:
- Near real cars, animals, or people that are unaware that an RC car is being
driven.
- In places where children and people gather
- In residential districts and parks
- In limited indoor spaces
- In wet conditions
- In the street
- In areas where loud noises can disturb others, such as hospitals and
residential areas.
- At night or anytime your line of sight to the model may be obstructed or
impaired in any way.
To prevent any serious personal injury and/or damage to property, please be
responsible when operating all remote controlled models.
CUSTOMER SUPPORT
XRAY Europe
K Vystavisku 6992
91101 Trenčín
Slovakia, EUROPE
Phone: [phone]
Fax: [phone]
E-mail: [e-mail]
We have made every effort to make these instructions as easy to understand as
possible. However, if you have any difficulties, problems, or questions, please do not
hesitate to contact the XRAY support team at [e-mail]. Also, please visit
our Web site at www.teamxray.com to find the latest updates, set-up information,
option parts, and many other goodies. We pride ourselves on taking excellent care
of our customers.
You can join thousands of XRAY fans and enthusiasts in our online community at:
www.teamxray.com
XRAY USA
RC America, 2030 Century Center Blvd #15
Irving, TX 75062
USA
Phone: [phone]
Fax: [phone]
E-mail: [email protected]
FAILURE TO FOLLOW THESE INSTRUCTIONS WILL BE CONSIDERED AS ABUSE AND/OR NEGLECT.

3
IMPORTANT NOTES – ELECTRICAL
• Insulate any exposed electrical wiring (using heat shrink tubing or electrical
tape) to prevent dangerous short circuits. Take maximum care in wiring,
connecting and insulating cables. Make sure cables are always connected
securely. Check connectors for if they become loose. And if so, reconnect
them securely. Never use RC models with damaged wires. A damaged wire
is extremely dangerous, and can cause short-circuits resulting in fire. Please
have wires repaired at your local hobby shop.
• Low battery power will result in loss of control. Loss of control can occur due
to a weak battery in either the transmitter or the receiver. Weak running
battery may also result in an out of control car if your car‘s receiver power is
supplied by the running battery. Stop operation immediately if the car starts
to slow down.
• When not using RC model, always disconnect and remove battery.
• Do not disassemble battery or cut battery cables. If the running battery
short-circuits, approximately 300W of electricity can be discharged, leading
to fire or burns. Never disassemble battery or cut battery cables.
• Use a recommended charger for the receiver and transmitter batteries
and follow the instructions correctly. Over-charging, incorrect charging,
or using inferior chargers can cause the batteries to become dangerously
hot. Recharge battery when necessary. Continual recharging may damage
battery and, in the worst case, could build up heat leading to fire. If battery
becomes extremely hot during recharging, please ask your local hobby
shop for check and/or repair and/or replacement.
• Regularly check the charger for potential hazards such as damage to the
cable, plug, casing or other defects. Ensure that any damage is rectified
before using the charger again. Modifying the charger may cause short-
circuit or overcharging leading to a serious accident. Therefore do not
modify the charger.
• Always unplug charger when recharging is finished.
• Do not recharge battery while battery is still warm. After use, battery retains
heat. Wait until it cools down before charging.
• Do not allow any metal part to short circuit the receiver batteries or other
electrical/electronic device on the model.
• Immediately stop running if your RC model gets wet as may cause short
circuit.
• Please dispose of batteries responsibly. Never put batteries into fire.
WARRANTY
XRAY guarantees this model kit to be free from defects in both material and
workmanship within 30 days of purchase. The total monetary value under
warranty will in no case exceed the cost of the original kit purchased. This
warranty does not cover any components damaged by use or modification
or as a result of wear. Part or parts missing from this kit must be reported
within 30 days of purchase. No part or parts will be sent under warranty
without proof of purchase. Should you find a defective or missing part, contact
the local distributor. Service and customer support will be provided through
local hobby store where you have purchased the kit, therefore make sure to
purchase any XRAY products at your local hobby store. This model racing car
is considered to be a high-performance racing vehicle. As such this vehicle
will be used in an extreme range of conditions and situations, all which may
cause premature wear or failure of any component. XRAY has no control over
usage of vehicles once they leave the dealer, therefore XRAY can only offer
warranty against all manufacturer‘s defects in materials, workmanship, and
assembly at point of sale and before use. No warranties are expressed or
implied that cover damage caused by what is considered normal use, or cover
or imply how long any model cars‘ components or electronic components will
last before requiring replacement.
Due to the high performance level of this model car you will need to
periodically maintain and replace consumable components. Any and all
warranty coverage will not cover replacement of any part or component
damaged by neglect, abuse, or improper or unreasonable use. This includes
but is not limited to damage from crashing, chemical and/or water damage,
excessive moisture, improper or no maintenance, or user modifications which
compromise the integrity of components. Warranty will not cover components
that are considered consumable on RC vehicles. XRAY does not pay nor refund
shipping on any component sent to XRAY or its distributors for warranty. XRAY
reserves the right to make the final determination of the warranty status of
any component or part.
Limitations of Liability
XRAY makes no other warranties expressed or implied. XRAY shall not be liable
for any loss, injury or damages, whether direct, indirect, special, incidental,
or consequential, arising from the use, misuse, or abuse of this product and/
or any product or accessory required to operate this product. In no case shall
XRAY‘s liability excess the monetary value of this product.
Take adequate safety precautions prior to operating this model. You
are responsible for this model’s assembly and safe operation.
Disregard of the any of the above cautions may lead to accidents,
personal injury, or property damage. XRAY MODEL RACING CARS
assumes no responsibility for any injury, damage, or misuse of this
product during assembly or operation, nor any addictions that may
arise from the use of this product.
All rights reserved.
QUALITY CERTIFICATE
XRAY MODEL RACING CARS uses only the highest quality materials, the
best compounds for molded parts and the most sophisticated manufacturing
processes of TQM (Total Quality Management). We guarantee that all parts
of a newly-purchased kit are manufactured with the highest regard to quality.
However, due to the many factors inherent in model racecar competition, we
cannot guarantee any parts once you start racing the car. Products which have
been worn out, abused, neglected or improperly operated will not be covered
under warranty.
We wish you enjoyment of this high-quality and high-performance RC car and
wish you best success on the track!
In line with our policy of continuous product development, the exact specifications of the kit may
vary. In the unlikely event of any problems with your new kit, you should contact the model shop
where you purchased it, quoting the part number.
We do reserve all rights to change any specification without prior notice. All rights reserved.
R/C & BUILDING TIPS
• Make sure all fasteners are properly tightened. Check them periodically.
• Make sure that chassis screws do not protrude from the chassis.
• For the best performance, it is very important that great care is taken to
ensure the free movement of all parts.
• Clean all ball-bearings so they move very easily and freely.
• Tap or pre-thread the plastic parts when threading screws.
• Self-tapping screws cut threads into the parts when being tightened. Do
not use excessive force when tightening the self-tapping screws because
you may strip out the thread in the plastic. We recommended you stop
tightening a screw when you feel some resistance.
• Ask your local hobby shop for any advice.
Please support your local hobby shop. We at XRAY Model Racing Cars support
all local hobby dealers. Therefore we ask you, if at all possible, to purchase
XRAY products at your hobby dealer and give them your support like we do.
If you have difficulty finding XRAY products, please check out www.teamxray.
com to get advice, or contact us via email at [e-mail], or contact
the XRAY distributor in your country.

4
EQUIPMENT REQUIRED
INCLUDED
(HUDY #106210)
Premium Graphite Grease
Transmitter Steering ServoReceiver
Lexan™ Paint
Battery Charger
Speed Controller
LiPo BatteryElectric Motor Pinion Gear
with Setscrew
Double-sided Tape
(HUDY #107875)
TL
CA
OILOIL
CA glueThreadlockBearing Oil
(HUDY #106230)
OIL
400cSt (#106340)
HUDY Premium Silicone Oils
* Kit includes smaller but sufficient amount
of oil and grease to build the car.
5.000cSt (#106450)
HUDY Premium Silicone Oils
TOOLS REQUIRED
Allen 1.5mm (#111545 - HUDY EXCLUSIVE Limited Edition)
Allen 2.0mm (#112045 - HUDY EXCLUSIVE Limited Edition)
Allen 3.0mm (#113045 - HUDY EXCLUSIVE Limited Edition)
Ball Allen 3.0mm (#133045 - HUDY EXCLUSIVE Limited Edition)
Socket 5.5mm (#175535 - HUDY EXCLUSIVE Limited Edition)
Socket 7.0mm (#177035 - HUDY EXCLUSIVE Limited Edition)
Reamer (#107602 - HUDY EXCLUSIVE Limited Edition)
Turnbuckle Wrench 3mm (HUDY #181030)
Turnbuckle Wrench 4mm (HUDY #181040)
Special Tool for turnbuckles, nuts (HUDY #181090)
Pocket Hobby Knife (HUDY #188981)
Side Cutters
(HUDY #189010)
Combination Pliers
(HUDY #189020)
Professional Multi Tool
(HUDY #183011)
Screwdriver 3.0mm (#153055 - HUDY EXCLUSIVE Limited Edition)
Tweezer Scissors (HUDY #188990)
Wheels & Tires & Inserts
(HUDY #803053 C3-28)
(HUDY #803062 A1-36)
190mm Bodyshell
Fibre Tape
(HUDY #107870)

5
CHASSIS PREPARATION
VIDEO TECH TIP
▶
CHASSIS PREPARATION
CA
At the beginning of each section is an exploded view of the parts to be assembled. There is also a list of all
the parts and part numbers that are related to the assembly of that section.
The part descriptions are color-coded to make it easier for you to identify the source of a part. Here are
what the different colors mean:
STYLE A - indicates parts that are included in the bag marked for the section.
STYLE B - indicates parts that are included in the box.
STYLE C - indicates parts that are already assembled from previous steps.
COLOR INDICATIONS
301011
304901
305134
BUILD TIPS & NOTES
XRAY offers wide range of optional tuning parts
which are listed in a table like this. Please refer
to the exploded view of each main section to verify
which part is included in the kit while all other parts
are available only as an optional part and must be
purchased separately.
SAMPLE OF OPTIONAL PARTS
#30XXXX TYPE1 OPTION 1
#30XXXX TYPE1 OPTION 2
#30XXXX TYPE1 INCLUDED
#30XXXX TYPE1 OPTION 3
CA
To protect and seal edges of graphite parts, sand edges smooth and then apply CA glue.
Do this for: chassis edges and countersunk holes.
Apply only a bit of CA glue in the countersunk holes.
VIDEO TECH TIP
▶
When a QR CODE is found in the instruction manual,
scan the code to be directed to an online video that
explains that feature or adjustment in more detail.
Make sure to watch all of the instructional videos to
get the most performance out of your car.
Alexander Hagberg (Factory Driver)

6
1. GEAR DIFFERENTIAL & FRONT SOLID AXLE
981210
P 2x10
972050
O 5x2
964050
S 5x15x0.3
➊
➋
➌
➍
➍➍
➎
➎
DETAIL
➎
STEP
304901 X4 GEAR DIFFERENTIAL - SET
304911 X4 COMPOSITE GEAR DIFF. CASE WITH 38T PULLEY & COVER
304930 COMPOSITE GEAR DIFF BEVEL & SATELLITE GEARS (2+4)
304970 ALU GEAR DIFF OUTDRIVE ADAPTER - 7075 T6 (2)
304980 COMPOSITE GEAR DIFF CROSS PIN
304990 DIFF GASKET (4)
305134 STEEL SOLID AXLE DRIVESHAFT ADAPTER - HUDY SPRING STEEL™ (2)
305178 X4 COMPOSITE SOLID AXLE 38T
902310 HEX SCREW SH M3x10 (10)
903258 HEX SCREW SFH M2.5x8 (10)
941015 BALL-BEARING 10x15x4 RUBBER SEALED - OIL (2)
964031 WASHER S 3.5x10x0.2 (10)
964050 WASHER S 5x15x0.3 (10)
971240 SILICONE O-RING 24x0.7 (10)
972050 SILICONE O-RING 5x2 (10)
981210 PIN 2x10 (10)
GEAR DIFFERENTIAL
BAG
304970
304911
964050
972050
304990
304911
903258
981210
981210
304970
941015
971240
972050
964031
304980
304930
304930
941015
305178
COMPOSITE SOLID AXLE
305134
305178
305134
941015
902310
941015
902310
#304932
GRAPHITE GEAR DIFF BEVEL &
SATELLITE GEARS (2+4)
#304932
GRAPHITE GEAR DIFF BEVEL &
SATELLITE GEARS (2+4)
DETAIL
#309003
SET OF CERAMIC BALL-BEARINGS (14)
#304971
HUDY SPRING STEEL™ OUTDRIVES (2)
#304971
HUDY SPRING STEEL™ OUTDRIVES (2)
#305137
STEEL LIGHTWEIGHT SOLID AXLE
DRIVESHAFT ADAPTERS HUDY
SPRING STEEL™(2)
If the diff is not turning freely after
assembly, use thin sand paper to
lightly polish the surface.
#305136
ALU SOLID DRIVESHAFT ADAPTERS (2)

7
REAR DIFFERENTIAL
VIDEO TECH TIP
▶
964031
S 3.5x10x0.2
1. GEAR DIFFERENTIAL & FRONT SOLID AXLE1. GEAR DIFFERENTIAL & FRONT SOLID AXLE
Use tweezers to
insert pin.
981210
P 2x10
972050
O 5x2
964050
S 5x15x0.3
➊
➋
➌
➍
➎
STEP DETAIL
Fill differential up to the top of the diff pin.
DO NOT fill the diff to the top of the housing.
If the cross does not enter into the
diff freely, use fine sand paper to
lightly polish the ends of the cross.
TO ENSURE YOU HAVE THE SAME AMOUNT OF OIL FROM REBUILD TO REBUILD, DO THE FOLLOWING:
NOTE
LIGHTER oil increases rear traction, HEAVIER oil increases on-power steering and
stability. It is important not to use lighter oils in high-traction conditions as this
would not increase traction, but would make the car loose as the car would become
too twitchy.
However, if the oil is too light, it could generate the same effect like the car has no
traction. Therefore it is very important to choose the correct oil very carefully. We
recommend using lighter oil first, then try heavier oil to better understand the effect
on the car’s behavior at the track. Choose the oil accordingly.
TIPS FOR FRONT DIFFERENTIAL
To increase off-power steering and mid-corner steering, the gear diff can also be used in front.
NOTE: If you use the gear diff in the front, we recommend using optional #304971 HUDY
Spring Steel™ outdrives because the stress on the outdrives in the front is much higher than
in the rear.
USE THESE OILS FOR FRONT DIFFERENTIAL
500.000cSt (HUDY #106650)
1 000.000cSt (HUDY #106692)
2 000.000cSt (HUDY #106694)
To make the front differential thicker, you can use cleaning gum instead of oil.
IMPORTANT!
Using cleaning gum instead of oil in the gear differential can lead to gear breakage because
the gears are working under dry conditions.
LOW TRACTION
1.000cSt (HUDY #106410)
2.000cSt (HUDY #106420)
TIPS FOR DIFFERENTIALS
#107865
HUDY Ultimate Digital Pocket
Scale 300g±0.01g
INITIAL SETTING
5.000cSt
➍
NOTE
ORIENTATION
MEDIUM TRACTION
2.000cSt (HUDY #106420)
3.000cSt (HUDY #106430)
4.000cSt (HUDY #106440)
5.000cSt (HUDY #106450)
HIGH TRACTION
5.000cSt (HUDY #106450)
6.000cSt (HUDY #106460)
7.000cSt (HUDY #106470)
8.000cSt (HUDY #106480)
9.000cSt (HUDY #106490)
10.000cSt (HUDY #106510)
VERY-HIGH TRACTION
10.000cSt (HUDY #106510)
11.000cSt (HUDY #106492)
12.000cSt (HUDY #106512)
15.000cSt (HUDY #106515)
20.000cSt (HUDY #106520)
➊ Put the diff (without oil) on the scale and check
the weight (approximately 9.50g).
➋ Slowly pour oil into the diff and watch the weight. Add 1.5g of oil
into the diff. The approximate weight of the diff including oil is 11.00g.
9.50g + 1.5g = 11.00g
To make sure that all the air is removed from the
diff oil, we recommend using the HUDY Air Vac.
If the diff is not turning freely after
assembly, use thin sand paper to
lightly polish the surface.
CUTAWAY VIEW
#304932
GRAPHITE GEAR DIFF BEVEL &
SATELLITE GEARS (2+4)
#104002
HUDY AIR VAC – VACUUM PUMP
g
9.50 g
11.00

8
1. GEAR DIFFERENTIAL & FRONT SOLID AXLE
902310
SH M3x10
941015
BB 10x15x4
941015
BB 10x15x4
OIL
903258
SFH M2.5x8
Tighten the screws equally but do
NOT tighten them completely.
Finish tightening in this order.
➊
➋
➌
➍
NOTE
ORIENTATION
DETAIL
971240
O 24x0.7
After disassembling the gear diff, the large O-ring may have an
increased size and may be more difficult to re-install. We recommend
either inserting the old O-ring carefully in the diff cover, or installing
a new O-ring if the old one cannot be made to fit properly.
BEARING OIL
(HUDY #106230)
OIL
BEARING OIL
(HUDY #106230)
OIL
1. FRONT SOLID AXLE
OIL
#305137
STEEL LIGHTWEIGHT SOLID AXLE
DRIVESHAFT ADAPTERS HUDY
SPRING STEEL™ (2)
#305136
ALU SOLID DRIVESHAFT ADAPTERS (2)
NOTE
ORIENTATION

9
901408
901310
903308
903308
901308
303260
303250
303260
901408
303250
303260
901308
303260
301012
X4 Alu Solid
301013
X4 Alu Flex
301011
X4 Graphite
302181-M (X4 Graphite)
302181-H (X4 Alu)
302180-M (X4 Graphite)
302180-H (X4 Alu)
303180-M (X4 Graphite)
303180-H (X4 Alu)
303181-M (X4 Graphite)
303181-H (X4 Alu)
303119-K (X4 Graphite)
303123-K (X4 Alu)
303119-K (X4 Graphite)
303123-K (X4 Alu)
901310
2. FRONT & REAR SUSPENSION
BAG
02
302180-M X4 COMPOSITE CFF™ CARBON-FIBER FUSION FRONT LOWER ARM - MEDIUM - RIGHT
302180-H X4 COMPOSITE CFF™ CARBON-FIBER FUSION FRONT LOWER ARM - HARD - RIGHT
302181-M X4 COMPOSITE CFF™ CARBON-FIBER FUSION FRONT LOWER ARM - MEDIUM - LEFT
302181-H X4 COMPOSITE CFF™ CARBON-FIBER FUSION FRONT LOWER ARM - HARD - LEFT
303119-K ALU SHIM 3x9x2.0MM - BLACK (10)
303123-K ALU SHIM 3x6x2.0MM - BLACK (10)
303180-M X4 COMPOSITE CFF™ CARBON-FIBER FUSION REAR LOWER ARM - MEDIUM - RIGHT
303180-H X4 COMPOSITE CFF™ CARBON-FIBER FUSION REAR LOWER ARM - HARD - RIGHT
303181-M X4 COMPOSITE CFF™ CARBON-FIBER FUSION REAR LOWER ARM - MEDIUM - LEFT
303181-H X4 COMPOSITE CFF™ CARBON-FIBER FUSION REAR LOWER ARM - HARD - LEFT
303250 X4 LOWER ARM BALL UNIVERSAL 6.0MM WITH HEX - HUDY SPRING STEEL™ (2)
303260 X4 PIVOT BALL 6.0MM WITH M3x5.5MM THREAD - HUDY SPRING STEEL™ (2)
901308 HEX SCREW SB M3x8 (10)
901310 HEX SCREW SB M3x10 (10)
901408 HEX SCREW SB M4x8 (10)
903308 HEX SCREW SFH M3x8 (10)
301011 X4 GRAPHITE CHASSIS 2.2MM
301012 X4 ALU SOLID CHASSIS 2.0MM - SWISS 7075 T6
301013 X4 ALU FLEX CHASSIS 2.0MM - SWISS 7075 T6
FRONT LOWER ARMS
#302181-M LEFT MEDIUM INCLUDED X4 GRAPHITE
#302180-M RIGHT MEDIUM INCLUDED X4 GRAPHITE
#302181-H LEFT HARD INCLUDED X4 ALU
#302180-H RIGHT HARD INCLUDED X4 ALU
REAR LOWER ARMS
#303181-M LEFT MEDIUM INCLUDED X4 GRAPHITE
#303180-M RIGHT MEDIUM INCLUDED X4 GRAPHITE
#303181-H LEFT HARD INCLUDED X4 ALU
#303180-H RIGHT HARD INCLUDED X4 ALU
#302121
FRONT ROLL-CENTER SPACER (2)
#302122
REAR ROLL-CENTER SPACER (2)

10
LOWER ARMS
VIDEO TECH TIP
▶
901310
SB M3x10
901408
SB M4x8
SUSPENSION ARMS
SUSPENSION ARMS
SUSPENSION ARMS
Make sure to use 10mm set
screw for rear arms.
LEFT = RIGHT
L=R
2.6mm
2. FRONT & REAR SUSPENSION
5.0mm
DETAIL
NOTE
ORIENTATION
NOTE
ORIENTATION
NOTE
ORIENTATION
NOTE
ORIENTATION
NOTE
ORIENTATION
NOTE
ORIENTATION
NOTE
ORIENTATION
NOTE
ORIENTATION
3x10mm
4x8mm
Install the pivot balls with Professional
Multi Tool (HUDY #183011).
Install the pivot balls with Professional
Multi Tool (HUDY #183011).
Press
straight
Press
straight

11
ROLL-CENTER
CHASSIS ALTERNATIVES
VIDEO TECH TIP
▶
303119-K
SHIM 3x9x2
303123-K
SHIM 3x6x2
903308
SFH M3x8
901308
SB M3x8
901408
SB M4x8
SUSPENSION ARMS
Make sure to use 8mm
set screw for front arms.
LEFT = RIGHT
L=R
3.0mm
3x9x2mm (X4 Graphite)
3x6x2mm (X4 Alu)
3x9x2mm (X4 Graphite)
3x6x2mm (X4 Alu)
2. FRONT & REAR SUSPENSION
3.0mm
3x8mm
2mm
2mm
2mm
2mm
4x8mm
DETAIL
FRONT LOWER ARMS
#302181-M LEFT MEDIUM INCLUDED X4 GRAPHITE
#302180-M RIGHT MEDIUM INCLUDED X4 GRAPHITE
#302181-H LEFT HARD INCLUDED X4 ALU
#302180-H RIGHT HARD INCLUDED X4 ALU
REAR LOWER ARMS
#303181-M LEFT MEDIUM INCLUDED X4 GRAPHITE
#303180-M RIGHT MEDIUM INCLUDED X4 GRAPHITE
#303181-H LEFT HARD INCLUDED X4 ALU
#303180-H RIGHT HARD INCLUDED X4 ALU
We recommend the MEDIUM hardness of the lower suspension arms for asphalt. These
arms are more flexible than the H (hard) arms.
For carpet racing and even some high-grip asphalt conditions, we recommend the
HARD suspension arms.
RAISING THE LOWER ARMS will raise the car’s roll center. Raising the lower
arms both front and rear will free up the car, and will make it initially
more responsive. Side bite will be decreased. A higher roll center is typically
recommended for asphalt racing.
LOWERING THE LOWER ARMS will lower the car’s roll center. Lowering both
the front and rear arms will lock in the car more, and will make it initially
less responsive. Side bite will be increased. A lower roll center is typically
recommended for carpet racing.
ROLL-CENTER ADJUSTMENT
#302121
FRONT ROLL-CENTER SPACER (2)
#302122
REAR ROLL-CENTER SPACER (2)

12
03
902306
302770
902314
903305
903305
903305
302062
902308
301570
302311
962042
305435
305524
902303
303122-K
296510-K
303127-K
903305
302056
302055
903305
903305
301570
302062
902308
301570
302970 362648
302771
302062
304901
301970
302771
302770
301970
303125-K
303125-K
902306
302062
305178
902308
301570
302311
902308
930407
302311
902308
902308 302311
902308
305880
305435
305579
970050
903318
296510-K
930308
303758
303075
903318
902314
303127-K
303139-K
3. CENTRAL TRANSMISSION
BAG
296510-K ALU COUNTERSUNK SHIM - BLACK (10)
301570 X4 ALU UPPER CLAMP - SWISS 7075 T6 (L+R)
301970 X4 ALU SHOCK TOWER FRONT - SWISS 7075 T6 (L+R)
302055 X4 ALU CHASSIS FRONT BRACE
302056 X4 GRAPHITE FRONT SUSPENSION BRACE
302062 COMPOSITE ADJUSTMENT BALL-BEARING HUB (4)
302311 X4 ALU CASTER BUSHING FRONT 4° / REAR 1.5° - 2 DOTS (4)
302770 X4 ALU LOWER ADJUSTMENT BULKHEAD - FRONT R / REAR L
302771 X4 ALU LOWER ADJUSTMENT BULKHEAD - FRONT L / REAR R
302970 X4 ALU SHOCK TOWER REAR - SWISS 7075 T6
303075 STEEL NUT (2)
303122-K ALU SHIM 3x6x1.0MM - BLACK (10)
303125-K ALU SHIM 3x6x3.0MM - BLACK (10)
303127-K ALU SHIM 3x6x4.0MM - BLACK (10)
303139-K ALU SHIM 3x6x7.0MM - BLACK (10)
303758 X4 ALU MOTOR MOUNT
305435 HIGH-PERFORMANCE DRIVE BELT 3x351MM
305524 X4 ALU SOLID LAYSHAFT & BEARINGS
305579 X4 COMPOSITE PULLEY FOR LAYSHAFT 20T
305880 OFFSET SPUR GEAR 110T / 64
362648 BALL END 4.9MM WITH THREAD 4MM (2)
902303 HEX SCREW SH M3x4 SMALL HEAD - STAINLESS (10)
902305 HEX SCREW SH M3x5 (10)
902306 HEX SCREW SH M3x6 (10)
902308 HEX SCREW SH M3x8 (10)
902314 HEX SCREW SH M3x14 (10)
903305 HEX SCREW SFH M3x5 (10)
903318 HEX SCREW SFH M3x18 (10)
930308 BALL-BEARING 3x8x4 STEEL SEALED - OIL (2)
930407 BALL-BEARING 4x7x2.5 STEEL SEALED - OIL (2)
962042 WASHER S 4x6x0.1 (10)
970050 O-RING 5x1 (10)
304901 X4 GEAR DIFFERENTIAL - SET
305178 X4 COMPOSITE SOLID AXLE 38T
SPUR GEARS 48P
#305772 72T / 48P OPTION
#305776 76T / 48P OPTION
#305778 78T / 48P OPTION
#305779 79T / 48P OPTION
#305781 81T / 48P OPTION
#305784 84T / 48P OPTION
#305784-O 84T / 48P OPTION
OFFSET SPUR GEARS 64P
#305860 90T / 64P OPTION
#305862 92T / 64P OPTION
#305866 96T / 64P OPTION
#305866-O 96T / 64P OPTION
#305869 99T / 64P OPTION
#305870 100T / 64P OPTION
#305870-O 100T / 64P OPTION
#305874 104T / 64P OPTION
#305876 106T / 64P OPTION
#305878 108T / 64P OPTION
#305880 110T / 64P INCLUDED
#305880-O 110T / 64P OPTION
#305882 112T / 64P OPTION
#305884 114T / 64P OPTION
#302063 or #302063-K
ALU ADJUSTMENT BALL-BEARING HUB (2)
#305436
HIGH-PERFORMANCE DRIVE BELT
LOW-FRICTION 3x351mm
902305
#303768
ALU CHASSIS T-BRACE - 7075 T6
#303767
BRASS CHASSIS T- BRACE - 10g
ALU CASTER BUSHINGS
#302310 FRONT 3° / REAR 5.5° 1 Dot OPTION
#302311 FRONT 4° / REAR 4.5° 2 Dots INCLUDED
#302312 FRONT 5° / REAR 3.5° 3 Dots OPTION (4g)
(4g)
(8g)
#309852
X4 BRASS WEIGHTS NICKEL COATED FOR MOTOR
MOUNT 4g+4g+8g

13
BUILDING THE
BULKHEADS
VIDEO TECH TIP
▶
903305
SFH M3x5
#305436
HIGH-PERFORMANCE DRIVE BELT
LOW-FRICTION 3x351mm
3. CENTRAL TRANSMISSION
#302063 or #302063-K
ALU ADJUSTMENT BALL-BEARING HUB (2)
DETAIL
NOTE
ORIENTATION
Milled Out Area inside
SOLID AXLE
SOLID AXLE
SHORTLONG
GEAR DIFF
DETAIL
DETAIL
NOTE
ORIENTATION
Milled Out Area inside

14
CASTER
VIDEO TECH TIP
▶
902308
SH M3x8
902308
SH M3x8
3. CENTRAL TRANSMISSION
NOTE ORIENTATION FOR ALL PARTS
Never use alu or titanium screws
for the eccentric bushings.
Never use alu or titanium screws
for the eccentric bushings.
ALU CASTER BUSHINGS
#302310 0.5° / 3.0° / 5.5° 1 Dot OPTION
#302311 1.5° / 4.0° / 4.5° 2 Dots INCLUDED
#302312 2.5° / 3.5° / 5.0° 3 Dots OPTION
1 Dot = 5.5º Caster
3 Dots = 3.5º Caster
2 Dots = 4.5º Caster
1 Dot = 0.5º Caster
CASTER CASTER
1 Dot = 3.0º Caster
3 Dots = 2.5º Caster 3 Dots = 5.0º Caster
2 Dots = 1.5º Caster
(INITIAL SETTING) (INITIAL SETTING)
2 Dots = 4.0º Caster
CASTER ADJUSTMENT
For most conditions, start with front
caster set at 4.0°. Increasing front
caster will increase steering (mainly
on-power), but it will also make the
car more difficult to drive and more
likely to traction roll.
A good starting point for the rear
caster is 1.5°. More rear caster will
increase initial steering making the
car more nervous to drive, but it can
help increase cornering speeds on
technical or higher grip tracks.
IMPORTANT
All 4 bushings at one end of the car must
be installed in the same orientation.
IMPORTANT
All 4 bushings at one end of the car must
be installed in the same orientation.

15
902303
SH M3x4
970050
O 5x1
966081
CH-CLIP 8
930407
BB 4x7x2.5
TO TIGHTEN FRONT BELT:
Rotate both front nylon hubs in arrow direction B
TO TIGHTEN REAR BELT:
Rotate both rear nylon hubs in arrow direction B
ALTERNATIVE
64P OFFSET SPUR GEAR
ALTERNATIVE
48P SPUR GEAR
BELT TENSION ADJUSTMENT & DIFFERENTIAL POSITION
A
B
BELT TENSION ADJUSTMENT & DIFFERENTIAL POSITION
B
A
L=R
L=R
A
B
AB
TO LOOSEN FRONT BELT:
Rotate both front nylon hubs in arrow direction A
TO LOOSEN REAR BELT:
Rotate both rear nylon hubs in arrow direction A
LOWER DIFF POSITION
UPPER DIFF POSITION
LOWER DIFF POSITION
UPPER DIFF POSITION
Front solid axle LOWER position - tab in top
notch - provides more forward traction,
but makes the car push on-power.
Recommended for low-traction tracks.
Recommended for low-medium traction tracks.
Front solid axle UPPER position - tab in
bottom notch - provides more steering, but
less forward traction.
Recommended for medium-high traction
tracks and technical tracks.
Recommended for medium-high traction tracks.
Rear diff LOWER position - tab in top notch -
provides more rear traction (mainly on-power),
makes the car more stable in chicanes, but can
cause a push on corner exit.
Rear diff UPPER position - tab in bottom notch -
provides more on-power steering, but makes
the rear less stable.
INITIAL POSITION for CARPET/ASPHALT
Place tab in this UPPER NOTCH
INITIAL POSITION for CARPET/ASPHALT
Place tab in this UPPER NOTCH
(INITIAL SETTING)
OIL
OIL
BEARING OIL
(HUDY #106230)
3. CENTRAL TRANSMISSION
1. 2. 2. 3.
OFFSET NOTE
ORIENTATION
CUTAWAY VIEW
DETAIL
NOTE
ORIENTATION
1mm
Snap Ring Pliers
(HUDY #189040)
#966081
CH-CLIP 8 (10)
INCLUDED IN THE
LAST AID BAG
Another alternative to secure
the pulley on the layshaft is
to use the CH-clip which is
included in the “Last Aid”
Bag. To mount the clip on
the layshaft, you have to use
special Snap Ring Pliers.
NOTE
ORIENTATION
SPUR GEARS 48P
#305772 72T OPTION
#305776 76T OPTION
#305778 78T OPTION
#305779 79T OPTION
#305781 81T OPTION
#305784 84T OPTION
#305784-O 84T OPTION
OFFSET SPUR GEARS 64P
#305860 90T OPTION
#305862 92T OPTION
#305866 96T OPTION
#305866-O 96T OPTION
#305869 99T OPTION
#305870 100T OPTION
#305870-O 100T OPTION
#305874 104T OPTION
#305876 106T OPTION
#305878 108T OPTION
#305880 110T INCLUDED
#305880-O 110T OPTION
#305882 112T OPTION
#305884 114T OPTION
DIFF HEIGHT BELT TENSION
ADJUSTMENT
VIDEO TECH TIP
▶
When using XRAY 48P spur gears or
aftermarket spur gears without an offset, use
the 3x5x1mm shims (#303141 not included)
between the gear and layshaft to create the
necessary clearance from the top deck.

16
BELT TENSION
ADJUSTMENT
VIDEO TECH TIP
▶
962042
S 4x6x0.1
902305
SH M3x5
303122-K
SHIM 3x6x1
303127-K
SHIM 3x6x4
303139-K
SHIM 3x6x7
903318
SFH M3x18
X4 BRASS WEIGHT FRONT RIGHT
FOR MOTOR MOUNT 4g
X4 BRASS WEIGHT REAR RIGHT
FOR MOTOR MOUNT 4g
0.1mm
BEARING OIL
(HUDY #106230)
OIL
BEARING OIL
(HUDY #106230)
OIL
3. CENTRAL TRANSMISSION
X4 BRASS WEIGHT FRONT LEFT
FOR MOTOR MOUNT 8g
#309852
X4 BRASS WEIGHTS NICKEL COATED FOR MOTOR MOUNT 4g+4g+8g
930308
BB 3x8x4
NOTE
ORIENTATION
NOTE
ORIENTATION
NOTE
ORIENTATION
1mm 7mm
4mm
4mm
This shim serves as the battery backstop.
To move the battery further away from the
center of the chassis, add additional shims.
This shim serves as the battery backstop.
To move the battery further away from the
center of the chassis, add additional shims.
These optional brass pieces place the extra weight close to the X4 center to minimize
the effects on the front-to-rear weight bias.
MOTOR MOUNT WEIGHT ADJUSTMENT

17
903305
SFH M3x5
MOTOR MOUNT FLEX ADJUSTMENT
MOTOR MOUNT FLEX
VIDEO TECH TIP
▶
Use only the 2 rearmost screws to attach the motor mount (as
shown). Do not install the 2 screws immediately in front of & behind
the spur gear. This allows the chassis to flex more in the central
area, and will improve traction (especially on-power). Rear grip
will be improved through the entire corner, but initial reaction will
decrease. This setting is recommended for low- to medium-traction
conditions, both on carpet and asphalt.
Using all screws to attach the motor mount (as shown) will give
the best steering response, but with the least mechanical traction.
The car will have more cornering speed, but will be more difficult
to drive. Mainly recommended for high-traction carpet conditions.
Use only the 3 rearmost screws to attach the motor mount (as
shown); do not install the very front screw. This gives a good
compromise between stability and initial response. The car will have
more rear grip than the full stiff setting, but will not be as stable as
the soft setting.
The motor mount is part of the chassis flex adjustment. Adding or removing screws from the mount will create different flex settings for different tracks and traction levels.
NOTE: When removing screws from the motor mount, the spur gear becomes more susceptible to breakage in crashes.
SOFT STIFFMEDIUM
(INITIAL SETTING)
3. CENTRAL TRANSMISSION

18
CHASSIS & TOP DECKS
VIDEO TECH TIP
▶
903306
SFH M3x6
903305
SFH M3x5
303121-K
SHIM 3x6x0.5
The brace provides chassis flex adjustment possibilities depending on which screws are connected.
CHASSIS FLEX ADJUSTMENT
902306
SH M3x6
NOTE ORIENTATION
DETAIL
0.5mm
SHIM
0.5mm
SHIM
CHANNEL
3x5mm
3x5mm
3x6mm
3x6mm
Use only for STIFF setting
0.5mm
0.5mm
Use only for STIFF
setting
3. CENTRAL TRANSMISSION
Install the brace using only the 2 forward
bottom centerline screws (as shown). (as
shown). This gives improved on-power
stability but still offers great off-power
steering and rotation. Recommended for
medium-high traction conditions and for
small, technical tracks with many hairpin
corners.
When the brace is not installed, the car
will have the most steering and rotation.
However, the car will be more difficult to
drive as it is less stable. Recommended
for medium-high traction conditions and
for small, technical tracks with many
hairpin corners.
Install the brace using all 3 bottom
centerline screws (as shown). This gives
improved on-power stability and traction,
but makes the car push more off-power.
Recommended for low- or high-traction
conditions where stability and traction is
needed.
In addition to installing all 3 bottom
centerline screws, also install the 2
rear side screws but with 0.5mm shims
between the brace and the chassis. This
setting gives maximum stability.
SOFT - MEDIUMSOFT - NO BRACE MEDIUM STIFF
#303768
ALU CHASSIS T-BRACE - 7075 T6
#303767
BRASS CHASSIS T-BRACE - 10g

19
CHASSIS & TOP DECKS
VIDEO TECH TIP
▶
903305
SFH M3x5
902314
SH M3x14
903305
SFH M3x5
902306
SH M3x6
303125-K
SHIM 3x6x3
Do not tighten the screw fully at first.
Only tighten the screws fully after
the shock tower is mounted with all
screws.
Do not tighten fully.
Tighten fully after assembly.
Do not tighten fully.
Do not use for
initial setting
3mm
IMPORTANT
3. CENTRAL TRANSMISSION
NOTE
ORIENTATION
This 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 initial setting is to run without this brace.
FRONT CROSS BRACE
FRONT BULKHEADS GRAPHITE BRACE
The cross brace reduces front chassis flex and improves
steering response. Recommended for most conditions EXCEPT
for higher-traction conditions or high-speed tracks where a
smoother steering response is preferred.

20
#302612-O
ALU ADJ. TURNBUCKLE M3 L/R 39mm
ORANGE - SWISS 7075 T6 (2)
#302610
ADJ. TURNBUCKLE L/R 39mm
HUDY SPRING STEEL™ (2)
#302590
ALU DUAL SERVO SAVER SCREW M3x7 (2)
#302571
X4 GRAPHITE STEERING PLATE SET
#303138-K or 303138-O
ALU SHIM 3x7x2.0mm (10)
#302664
COMPOSITE BALL JOINT 4.9mm
UNIDIRECTIONAL - OPEN (4)
4. STEERING
BAG
04
902305
301070 X4 GRAPHITE UPPER DECK 2.0MM
301158 TOP DECK HEX SCREW M3x5.5 - HUDY SPRING STEEL™ (2)
302517-K X4 ALU DUAL STEERING ARM - BLACK + BALL-BEARINGS (2)
302539 X4 ALU STEERING POST FOR DUAL SERVO SAVER (2)
302544 ALU SHIM FOR RADIAL PLAY ADJUSTMENT OF STEERING ARM (2)
302552 ALU STEERING PLATE 8.0MM FOR DUAL SERVO SAVER
302612 ALU ADJ. TURNBUCKLE M3 L/R 39 MM - SWISS 7075 T6 (2)
302663 COMPOSITE BALL JOINT 5 MM - OPEN - V2 (8)
303122-K ALU SHIM 3x6x1.0MM - BLACK (10)
303137-K ALU SHIM 3x7.5x2.0MM - BLACK (10)
303143 ALU SHIM 3x5x0.25MM (10)
303210 REAR TURNBUCKLE L/R 26 MM - HUDY SPRING STEEL (2)
303454 BALL JOINT 4.9MM - OPEN (4)
306219 COMPOSITE SET OF SERVO SHIMS (4)
362648 BALL END 4.9MM WITH THREAD 4MM (2)
362652 BALL END 4.9MM WITH THREAD 10MM (2)
372503 COMPOSITE SERVO SAVER - X-STIFF - SET - V2
372649 BALL END 4.2MM WITH 4MM THREAD (2)
372661 COMPOSITE STEERING BALL-JOINT OPEN 4.2 MM (4)
902303 HEX SCREW SH M3x4 SMALL HEAD - STAINLESS (10)
902305 HEX SCREW SH M3x5 (10)
902306 HEX SCREW SH M3x6 (10)
903305 HEX SCREW SFH M3x5 (10)
930306 BALL-BEARING 3x6x2.5 STEEL-SEALED - OILED (2)
940508 BALL-BEARING 5x8x2.5 RUBBER-SEALED - OILED (2)
302663
302612
372661
372661
302612
302663
903305
302539
302517-K
372503
372503
372503
306219
362652
902305
302544
303210
303454
302663
940508
940508
301070
303143
372649
902306
303122-K
302552
930306
301158
902306
362648
902305
902303
303137-K
301158
#301071
X4 GRAPHITE UPPER DECK 1.6mm
#301072 X4 GRAPHITE UPPER DECK - SPLIT FRONT - 2.0mm
#301073 X4 GRAPHITE UPPER DECK - SPLIT REAR - 2.0mm