Xray T4'21 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
450cSt (#106345)
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
Tweezer
Allen 1.5mm (#111545 - HUDY EXCLUSIVE Limited Edition)
Allen 2.0mm (#112045- HUDY EXCLUSIVE Limited Edition)
Allen 3.0mm (#113045- HUDY EXCLUSIVE Limited Edition)
Socket 5.5mm (#175535 - HUDY EXCLUSIVE Limited Edition)
Socket 7.0mm (#177035 - HUDY EXCLUSIVE Limited Edition)
Arm Reamer 3.0mm (#107643 - 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)
Scissors (HUDY #188990)
Side Cutters
(HUDY #189010)
Combination Pliers
(HUDY #189020)
Professional Multi Tool
(HUDY #183011)
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
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
301004
304900
305134
NOT INCLUDED
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, countersunk holes, and shock towers.
Apply only a bit of CA glue in the 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
Use tweezers to
insert pin.
981210
P 2x10
981210
P 2x10
972050
O 5x2
972050
O 5x2
964050
S 5x15x0.3
964050
S 5x15x0.3
➊
➋
➌
➍
➍➍
➎
➎
➊
➋
➌
➍
➎
DETAIL
➎
STEP
STEP DETAIL
304900 XRAY GEAR DIFFERENTIAL - SET
304910 COMPOSITE GEAR DIFF. CASE & 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)
305188 COMPOSITE SOLID AXLE 38T - SET
902310 HEX SCREW SH M3x10 (10)
903256 HEX SCREW SFH M2.5x6 (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
➍
NOTE
ORIENTATION
#304971
HUDY SPRING STEEL™ OUTDRIVES
#304971
HUDY SPRING STEEL™ OUTDRIVES
BAG
304970
304910
964050
972050
304990
304910
903256
981210
981210
304970
941015
971240
972050
964031
304980
304930
304930
941015
#305137
STEEL LIGHTWEIGHT SOLID AXLE DRIVESHAFT
ADAPTERS HUDY SPRING STEEL™
#305136
ALU SOLID DRIVESHAFT ADAPTERS
305188
941015
941015
305134
902310
305134
305188
902310
COMPOSITE SOLID AXLE
CUTAWAY VIEW
#304932
GRAPHITE GEAR DIFF BEVEL & SATELLITE GEARS (2+4)
#304932
GRAPHITE GEAR DIFF BEVEL & SATELLITE GEARS (2+4)
DETAIL
#309002
SET OF CERAMIC BALL-BEARINGS (14)

7
HUDY AIR VAC DIFF
BUILD
VIDEO TECH TIP
▶
964031
S 3.5x10x0.2
1. GEAR DIFFERENTIAL & FRONT SOLID AXLE1. GEAR DIFFERENTIAL & FRONT SOLID AXLE
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.
Fill differential up to the top of the diff pin.
DO NOT fill the diff to the top of the housing.
TO ENSURE YOU HAVE THE SAME AMOUNT OF OIL FROM REBUILD TO REBUILD, DO THE FOLLOWING:
NOTE
SOFTER oil increases rear traction, HARDER oil increases on-power steering and
stability. It is important not to use soft 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 soft, 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 softer oil first, then try harder oil to better understand the effect
on the car’s behavior at the track. Choose the oil accordingly.
TIPS FOR FRONT DIFFERENTIAL
To increase on-power steering and cornering speed, the gear diff can also be used in the 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 tighter, 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
7.90g 9.40g
#107865
HUDY Ultimate Digital Pocket
Scale 300g±0.01g
INITIAL SETTING
5.000cSt
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)
SUPER-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 7.90g)
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 9.40g.
7.9g + 1.5g = 9.4g
To make sure that all the air is removed
from the diff oil, we recommend using the
HUDY Air Vac.
#304932
GRAPHITE GEAR DIFF BEVEL &
SATELLITE GEARS (2+4)
#104002
HUDY AIR VAC – VACUUM PUMP

8
FRONT SOLID AXLE
1. GEAR DIFFERENTIAL & FRONT SOLID AXLE
902310
SH M3x10
941015
BB 10x15x4
941015
BB 10x15x4
OIL
903256
SFH M2.5x6
Tighten the screws equally but do
NOT tighten them completely.
Finish tightening in this order.
➊
➋
➌
➍
NOTE
ORIENTATION
DETAIL
BEARING OIL
(HUDY #106230)
OIL
OIL
BEARING OIL
(HUDY #106230)
OIL
#305137
STEEL LIGHTWEIGHT SOLID AXLE DRIVESHAFT
ADAPTERS HUDY SPRING STEEL™
#305136
ALU SOLID DRIVESHAFT ADAPTERS

9
305188
303759
930407
303120
903305
902308
970050
902305
305578
970050
962042
303120
303764
903304
303076
305523 305880
902303
305578
305578
304900
903305
903305
902306
902306
902306
902306
902306
305435
305435
302768
302769
302769
302768
301550
301550
301550
301960
301550
302062
302062
302062
302062
902306
302960
301005
T4’21 Alu Solid
301006
T4’21 Alu Flex
301004
T4’21 Graphite
902305
903305
903305
903306
2. CENTRAL TRANSMISSION
BAG
02
301550 ALU UPPER CLAMP WITH 2 ADJ. ROLL-CENTERS (L+R)
301960 ULP GRAPHITE SHOCK TOWER FRONT 3.0MM
302062 COMPOSITE ADJUSTMENT BALL-BEARING HUB (4)
302768 ALU LOWER ADJUSTMENT BULKHEAD - FRONT R / REAR L
302769 ALU LOWER ADJUSTMENT BULKHEAD - FRONT L / REAR R
302960 ULP GRAPHITE SHOCK TOWER REAR 3.0MM
303076 ALU BELT TENSIONER BUSHING
303120 SET OF ALU SHIM (0.5MM, 1.5MM, 2.5MM)
303759 ALU MOTOR MOUNT
303764 ALU CHASSIS BRACE - 7075 T6
305435 HIGH-PERFORMANCE DRIVE BELT 3x351MM
305523 ALU SOLID LAYSHAFT WITH BEARINGS
305578 FIXED PULLEY FOR LAYSHAFT WITH BEARINGS 20T (2)
305880 OFFSET SPUR GEAR 110T / 64
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)
903304 HEX SCREW SFH M3x4 (10)
903305 HEX SCREW SFH M3x5 (10)
903306 HEX SCREW SFH M3x6 (10)
930407 BALL-BEARING 4x7x2.5 STEEL SEALED - OIL (2)
962042 WASHER S 4x6x0.1 (10)
970050 O-RING 5x1 (10)
304900 XRAY GEAR DIFFERENTIAL - SET
305188 COMPOSITE SOLID AXLE 38T - SET
301004 T4’21 GRAPHITE CHASSIS 2.2MM
301005 T4’21 ALU SOLID CHASSIS 2.0MM - SWISS 7075 T6
301006 T4’21 ALU FLEX CHASSIS 2.0MM - SWISS 7075 T6
OFFSET 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
#305578-O
FIXED PULLEY 20T - GRAPHITE (2)
#183001
HUDY PROFESSIONAL BULKHEAD
ALIGNMENT TOOL 17MM
#302063 or #302063-K
ALU ADJUSTMENT BALL-BEARING HUB (2)
#301007
T4’21 ALU EXTRA-FLEX CHASSIS 2.0MM
- SWISS 7075 T6
#305436
HIGH-PERFORMANCE DRIVE BELT
LOW-FRICTION 3x351MM

10
T4 BELT TENSION
VIDEO TECH TIP
▶
903305
SFH M3x5
#183001
HUDY PROFESSIONAL BULKHEAD ALIGNMENT TOOL 17MM
To align the bulkheads straight, we suggest using
the HUDY Professional Bulkhead Alignment tool.
See page 13
2. CENTRAL TRANSMISSION
SOLID AXLE
GEAR DIFF
#302063 OR #302063-K
ALU ADJUSTMENT BALL-BEARING HUB (2)
#302063 OR #302063-K
ALU ADJUSTMENT BALL-BEARING HUB (2)
DETAIL
NOTE
ORIENTATION
DETAIL
NOTE
ORIENTATION

11
902303
SH M3x4
970050
O 5x1
966081
CH-CLIP 8
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
FRONT BELT TENSION ADJUSTMENT
AB
REAR BELT TENSION ADJUSTMENT
BA
L=R L=R
ABA
B
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 front 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 front
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 makes the car
push on-power.
Rear diff UPPER position - tab in bottom notch -
provides more on-power steering, but makes the
rear slightly more loose.
INITIAL POSITION for CARPET/ASPHALT
Place tab in this BOTTOM NOTCH
INITIAL POSITION for CARPET/ASPHALT
Place tab in this BOTTOM NOTCH
NOTE
ORIENTATION
NOTE
ORIENTATION
NOTE
ORIENTATION
SHORT side
LONG side
2. CENTRAL TRANSMISSION
1. 2. 3.
CUTAWAY VIEW
#305578-O
FIXED PULLEY 20T
GRAPHITE (2)
DETAIL
NOTE
ORIENTATION
NOTE
ORIENTATION
Snap Ring Pliers
#966081 CH-CLIP 8 (10)
INCLUDED IN THE LAST AID BAG
Another alternative to secure the pulley
on the layshaft is to use the Clip which is
included in the “Last Aid” Bag. To mount the
clip on the layshaft, you have to use special
Snap Ring Pliers. Snap Ring Pliers
#966081 CH-CLIP 8 (10)
INCLUDED IN THE LAST AID BAG
Another alternative to secure the pulley
on the layshaft is to use the Clip which is
included in the “Last Aid” Bag. To mount the
clip on the layshaft, you have to use special
Snap Ring Pliers.
OFFSET 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

12
903305
SFH M3x5
962042
S 4x6x0.1
902305
SH M3x5
902308
SH M3x8
MOTOR MOUNT FLEX ADJUSTMENT
930407
BB 4x7x2.5
3x5mm
3x8mm
0.1mm
OIL
BEARING OIL
(HUDY #106230)
BELT TENSIONER
VIDEO TECH TIP
▶
FLEX OPTIONS
VIDEO TECH TIP
▶
2. CENTRAL TRANSMISSION
Use only the 3 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 4 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. By adding and removing the screws from the motor mount you get different flex possibilities for different tracks and traction conditions.
NOTE: By removing screws from the motor mount, the spur gear becomes more susceptible to breakage in crashes.
SOFT STIFFMEDIUM (INITIAL SETTING)

13
902306
SH M3x6
902306
SH M3x6
902306
SH M3x6
In order to have perfectly aligned bulkheads, we recommend using the
Hudy Professional Bulkhead Alignment tool.
#183001
HUDY PROFESSIONAL
BULKHEAD ALIGNMENT
TOOL 17MM
L=R L=R
DO NOT TIGHTEN FULLY
DO NOT TIGHTEN FULLY
DO NOT TIGHTEN FULLY
DO NOT TIGHTEN FULLY
FINISH TIGHTENING IN THIS ORDER. FINISH TIGHTENING IN THIS ORDER.
FULLY TIGHTEN
FULLY TIGHTEN
FULLY TIGHTEN
FULLY TIGHTEN
Shock tower screws (4)
Shock tower screws (4)
Bulkhead screws (4)
Bulkhead screws (4)
2. CENTRAL TRANSMISSION

14
FLEX OPTIONS
VIDEO TECH TIP
▶
903304
SFH M3x4
903305
SFH M3x5
903306
SFH M3x6
303120
SHIM 3x6x0.5
The brace great chassis flex adjustment possibilities depending on which screws are connected
CHASSIS FLEX ADJUSTMENT
902305
SH M3x5
303120
SHIM 3x6x0.5
NOTE ORIENTATION
DETAIL
0.5mm SHIM0.5mm SHIM
CHANNEL
3x4mm
3x5mm
3x5mm
Do not use 3x6mm screws for
initial setting
0.5mm
0.5mm
(INITIAL SETTING)
Do not use shims for
initial setting
2. CENTRAL TRANSMISSION
Install the brace using only the 2 forward bottom screws
(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.
If 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.
In addition to all screws used for the “medium” setting, install a front screw at the top;
ensure you insert a 0.5mm shim between the T-brace and the motor mount (as shown).
This gives improved stability. Recommended for very-high-traction conditions to improve
stability, and also for very-low-traction conditions to generate more traction and stability.
0.5mm
3x5mm
Install the brace using the 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 all screws used for the “stiff” setting, install the 2 rear side screws; ensure
you insert 0.5mm shims between the T-brace and the chassis. This setting gives maximum
stability.
SOFT - MEDIUMSOFT - WITHOUT BRACE
STIFF
MEDIUM
EXTRA STIFF

15
DOWNSTOPS
VIDEO TECH TIP
▶
BAG
03
901308
SB M3x8
901408
SB M4x8
REAR ARMS - LONG
#303173-H HARD RIGHT OPTION
#303174-H HARD LEFT OPTION
#303173-G GRAPHITE RIGHT INCLUDED
#303174-G GRAPHITE LEFT INCLUDED
FRONT ARMS - LONG
#302173-H HARD RIGHT OPTION
#302174-H HARD LEFT OPTION
#302173-G GRAPHITE RIGHT INCLUDED
#302174-G GRAPHITE LEFT INCLUDED
2x
REAR ARMS - LONG
#303173-H HARD RIGHT OPTION
#303174-H HARD LEFT OPTION
#303173-G GRAPHITE RIGHT INCLUDED
#303174-G GRAPHITE LEFT INCLUDED
#307217 TITANIUM SUSPENSION PIVOT PIN (2)
302173-G
303173-G
#303731 ALU LOWER 2-PIECE
SUSPENSION 0.25 ECCENTRIC
HOLDER STAND
REAR ARMS
3. FRONT & REAR SUSPENSION
302173-G FRONT SUSPENSION ARM LONG RIGHT - GRAPHITE
302174-G FRONT SUSPENSION ARM LONG LEFT - GRAPHITE
302713 ALU FRONT LOWER 1-PIECE SUSPENSION HOLDER - FRONT - FF
302723 ALU FRONT LOWER 1-PIECE SUSPENSION HOLDER - REAR - FR
303129 COMPOSITE SET OF WHEELBASE SHIMS (3x1MM; 1x2MM) (2)
303173-G REAR SUSPENSION ARM LONG RIGHT - GRAPHITE
303174-G REAR SUSPENSION ARM LONG LEFT - GRAPHITE
303723 ALU REAR LOWER 1-PIECE SUSPENSION HOLDER - REAR - RR
303732 ALU REAR SUSP. HOLDER WITH CENTERING PIN - FRONT (1)
307216 SUSPENSION PIVOT PIN (2)
362315 ECCENTRIC BUSHING SET (2)
901308 HEX SCREW SB M3x8 (10)
901408 HEX SCREW SB M4x8 (10)
903306 HEX SCREW SFH M3x6 (10)
362315
362315
303129
303129
901308
303174-G
303723
303129
303129
901408
901408
903306
307216
362315
307216
302174-G
302723
901308
903306
362315
302713
303732
3mm
REAR LEFT ARM REAR RIGHT ARM
2mm
L=R
INITIAL SETTING
LEFT REAR ARM 3x8mm
4x8mm

16
DOWNSTOPS
VIDEO TECH TIP
▶
901308
SB M3x8
901408
SB M4x8
2x
FRONT ARMS - LONG
#302173-H HARD RIGHT OPTION
#302174-H HARD LEFT OPTION
#302173-G GRAPHITE RIGHT INCLUDED
#302174-G GRAPHITE LEFT INCLUDED
1mm
903306
SFH M3x6
NOTE
ORIENTATION
FRONT ARMS
ECCENTRIC BUSHINGS HAVE TWO DIFFERENT OFFSETS FROM THE CENTER
Middle position = 0.5 mm or 0.5° from center
Outer position = 1mm or 1° from center
The XRAY rear alu lower suspension holders provide even greater range of adjustment for the rear suspension.
Using different combinations of eccentric bushings, fine adjustment of rear squat, rear toe-in, rear roll center, and
rear track-width can be obtained. For more information about the influence of rear squat, rear toe-in, rear roll
center and rear track-width on car handling, please refer to HUDY Set-up Book (#209100).
Marked
“RR”
REAR SUSPENSION
#303731 ALU LOWER 2-PIECE
SUSPENSION 0.25 ECCENTRIC
HOLDER STAND
INITIAL SETTING
FOR CARPET
INITIAL SETTING
FOR ASPHALT
INITIAL SETTING
FOR ASPHALT
INITIAL SETTING
FOR CARPET
ECCENTRIC BUSHINGS
ECCENTRIC BUSHINGS
NOTE
ORIENTATION
NOTE
ORIENTATION
0.5º 1.0º
0.5º 1.0º
3mm
INITIAL SETTING
4x8mm
3x8mm
FRONT RIGHT ARM
L=R
FRONT LEFT ARMFRONT RIGHT ARM
2.2mm
3. FRONT & REAR SUSPENSION
303129
SHIM 3x6x1
1mm
L=R
#307217
TITANIUM SUSPENSION
PIVOT PIN (2)
L=R
#107633 HUDY Arm Reamer 3.0mm
It is extremely important that the arms move freely
on the pivot pins. If they do not, use the Arm Reamer
(3.0mm) to slightly resize the holes in the arms.
Do not use INNER positions. Available positions
COMPOSITE ECCENTRIC
BUSHINGS

17
903306
SFH M3x6
303129
SHIM 3x6x1
903306
SFH M3x6
1mm
1mm
Marked
“FR”
FRONT SUSPENSION
ECCENTRIC BUSHINGS HAVE TWO DIFFERENT OFFSETS FROM THE CENTER.
Middle position = 0.5 mm or 0.5° from center
Outer position = 1mm or 1° from center
The XRAY front alu lower suspension holders provide even greater range of adjustment for the front suspension. Using different combinations of eccentric bushings, fine adjustment of front
anti-squat, front kick-up, front toe-in, front roll center, and front track-width can be obtained. For more information about the influence of front anti-dive, front kick-up, front toe-in, front
roll center and front track-width on car handling, please refer to HUDY Set-up Book.
Marked
“FF”
All possible mounting
alternatives of eccentric bushings
FRONT SUSPENSION
NOTE
ORIENTATION
NOTE
ORIENTATION
INITIAL SETTING
FOR ASPHALT
INITIAL SETTING
FOR CARPET
ECCENTRIC BUSHINGS
0.5º 1.0º
INITIAL SETTING
FOR ASPHALT
INITIAL SETTING
FOR CARPET
ECCENTRIC BUSHINGS
0.5º 1.0º
NOTE ORIENTATION
3. FRONT & REAR SUSPENSION
#307217
TITANIUM SUSPENSION
PIVOT PIN (2)
It is extremely important that the arms move freely
on the pivot pins. If they do not, use the Arm Reamer
(3.0mm) to slightly resize the holes in the arms.
L=R
#107633 HUDY Arm Reamer 3.0mm

18
#302612-O
ALU ADJ. TURNBUCKLE M3 L/R 39mm
ORANGE - SWISS 7075 T6 (2)
#302610
ADJ. TURNBUCKLE L/R 40mm
HUDY SPRING STEEL™ (2)
#301063
T4’21 GRAPHITE UPPER DECK 1.6MM
#302590
ALU DUAL SERVO SAVER SCREW M3x7 (2)
#302547
ALU STEERING PLATE 8.5MM FOR DUAL SERVO SAVER - ORANGE
4. STEERING
BAG
04
902306
301062 T4’21 GRAPHITE UPPER DECK 2.0MM
301172 ALU UPPER DECK COLLAR FOR FLEX ELIMINATION
302526 COMPOSITE DUAL SERVO SAVER ARM
302537 ALU STEERING POST FOR DUAL SERVO SAVER (2)
302544 ALU SHIM FOR RADIAL PLAY ADJUSTMENT OF STEERING ARM (2)
302548 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)
303126 ALU SHIM 3x6x5.0MM (10)
303129 COMPOSITE SET OF SHIMS (3x1MM; 1x2MM) (2)
303210 REAR TURNBUCKLE L/R 26 MM - HUDY SPRING STEEL (2)
303454 BALL JOINT 4.9MM - OPEN (4)
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)
902305 HEX SCREW SH M3x5 (10)
902306 HEX SCREW SH M3x6 (10)
903306 HEX SCREW SFH M3x6 (10)
903308 HEX SCREW SFH M3x8 (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
903306
302537
302526
372503
372503
372503
303129
362652
902305
302544
903308
303210
303454
940508
940508
301062
372649
303129
302548
930306
301172
902306
303126
362652
902306
#302525
ALU DUAL-SERVO SAVER ARM
#302525-K
ALU DUAL-SERVO SAVER ARM

19
HOW TO BUILD A PLAY
FREE STEERING
VIDEO TECH TIP
▶
HUDY MULTI-TOOL USE
VIDEO TECH TIP
▶
940508
BB 5x8x2.5
930306
BB 3x6x2.5
903308
SFH M3x8
2x
L=R
303129
SHIM 3x6x1
approx. 17mm
NOTE ORIENTATION
(outside)
NOTE ORIENTATION
(outside)
4mm THREAD
STEERING LINKS
SERVO LINK
Adjust servo link to fit your servo
26mm
INITIAL SETTING (1mm shim)
1mm 1mm 1mm 2mm
To change Ackermann angle, use 2 identical
shims (of same thickness) between the alu
steering plate and ball ends.
2x
2x
L=R
THREAD
THREAD
BEARING OIL
(HUDY #106230)
OIL
Install the pivot balls with Professional
Multi Tool (HUDY #183011)
#302612-O
ALU ADJ. TURNBUCKLE M3
L/R 39mm ORANGE - SWISS
7075 T6 (2)
#302610
ADJ. TURNBUCKLE L/R 40mm
HUDY SPRING STEEL (2)
3x6x2.5mm
5x8x2.5mm
Tighten the screws gently but fully, and then loosen 1/3
turn so the composite dual-servo saver moves freely.
➊ Tighten fully
➋ Loosen 1/3 ccw
➌ Check free movement
(120° CCW)
4. STEERING
THREAD
THREAD
OIL
NOTE
ORIENTATION
NOTE ORIENTATION
Long side = Ball joint open
#302547
ALU STEERING PLATE 8.5MM FOR DUAL SERVO SAVER - ORANGE
Optional 8.5mm alu steering plate improves steering response, but makes the car
more difficult to drive in chicanes. Recommended for small, technical tracks, or
tracks with many hairpin corners.
#302525
ALU DUAL SERVO SAVER ARM
#302525-K
ALU DUAL SERVO SAVER ARM
We recommend using the aluminum dual-servo saver arms when better steering
response is needed. Also recommended for asphalt tracks.
NOTE ORIENTATION
Ball joint open
NOTE ORIENTATION
Ball joint open

20
STEERING SYSTEM
SET-UP
HOW TO BUILD A PLAY
FREE STEERING
VIDEO TECH TIP
▶
VIDEO TECH TIP
▶
303129
SHIM 3x6x2
303126
SHIM 3x6x5
902305
SH M3x5
903306
SFH M3x6
2mm 2mm
5mm
10mm
THREAD
10mm THREAD
HUDY ALU SERVO HORNS
#293501 KO, Sanwa - 23T
#293502 Hitec - 24T
#293503 Futaba - 25T
HUDY CLAMP ALU SERVO HORNS
#293407 KO, Sanwa - 23T
#293408 Hitec - 24T
#293409 Futaba - 25T
ALU SERVO HORNS - OFFSET
#293491 KO, Sanwa - 23T
#293492 Hitec - 24T
#293493 Futaba - 25T
CLAMP ALU SERVO HORNS - OFFSET
#293401 KO, Sanwa - 23T
#293402 Hitec - 24T
#293403 Futaba - 25T
For more in-corner steering and better steering response, aluminum servo horns may be used.
IMPORTANT!
When an aluminum horn is used, the steering servo saver is not used. This increases the risk of breaking the servo in serious crashes.
HUDY ALU SERVO HORNS
#293497 KO, Sanwa - 23T
#293498 Hitec - 24T
#293499 Futaba - 25T
HUDY CLAMP ALU SERVO HORNS
#293404 KO, Sanwa - 23T
#293405 Hitec - 24T
#293406 Futaba - 25T
#302590
ALU DUAL SERVO SAVER SCREW M3x7 (2)
The optional screw removes excessive radial play
of the steering.
INITIAL SETTING
H = (24T)
F = (25T)
K = (23T)
4. STEERING
When using optional #302525-K or #302525
aluminum steering arms, we suggest using
optional shims.
#303134-K (3x7.5x1.5mm)
#303123-K (3x6x2mm)
When you want to eliminate steering lock in
high-traction conditions.
3x6x2mm
3x7.5x1.5mm
3x7.5x1.5mm