Xray T1 EVO2 Product guide

IInnttrroodduuccttiioonn
Car setup can be a difficult and controversial step in getting your car to its
maximum performance. Even if you have extensive knowledge of your car
and know all the theories on handling dynamics, this knowledge is still
tedious to use in practice because of the inherent complexity in the set-up
process itself.
Your new T EVO2 touring car with fully independent suspension features the
highest number of adjustments possible to get the most performance out of
any track condition. Setting the car is necessary to make the car perform well.
We have developed these straight-forward procedures to help you set up
your T EVO2 properly and easily. Always follow these procedures step-by-
step, in the order presented, and always make sure that you make equal
adjustments on both left and right sides of the car.
The set-up described here is a good starting point, but you may adjust the
settings to better suit different track conditions. Only change one thing at a
time, in order to get a better understanding of what consequence each
change has on the handling of the car. Remember to document all the
changes you make, and the effect they have on your car and lap times.
XRAY publishes new set-up information, hot tuning tips, and the latest hop-
ups for your T EVO2 on the www.teamxray.com website. XRAY, as a member
of www.myTSN.com, publishes all news at the myTSN.com RC portal. As a
proud owner of a T EVO2, you can register your car at myTSN.com and you
may post your own set-ups to the website, either as public or private data,
and even link the set-ups directly to a particular track or event (providing that
those are present on myTSN.com).
In the following pages we have used the tools and accessories listed below
for perfect and optimal adjustment:
# 0 820 HUDY Set-up Board for / 0
# 0 82 HUDY Set-up Board Decal for / 0
# 0 9300 HUDY Universal Set-up for All / 0 Touring Cars
# 0 7702 HUDY Chassis Droop Gauge Support Blocks
# 0 77 2 HUDY Chassis Droop Gauge -3 to 0 mm
# 0 77 5 HUDY Ride Height Gauge
# 0 76 0 HUDY Caster Clip Remover Tool
# 0 7880 HUDY Chassis Balancing Tool
# 8 030 HUDY 3mm Turnbuckle Tool
Final Adjustments 3
CChhaassssiiss PPrreeppaarreeaattiioonn33
RRaaddiioo AAddjjuussttmmeennttss33
SSppeeeedd CCoonnttrrooll AAddjjuussttmmeenntt44
CCoonnnneeccttiinngg tthhee MMoottoorr44
BBaatttteerryy aanndd SSppeeeedd CCoonnttrrooll PPllaacceemmeenntt44
RReecceeiivveerr ppllaacceemmeenntt55
MMoottoorr GGeeaarriinngg55
DDiiffffeerreennttiiaall AAddjjuussttmmeenntt66
OOnnee--wwaayy PPuulllleeyy AAddjjuussttmmeenntt88
OOnnee--wwaayy FFrroonntt DDiiffffeerreennttiiaall99
SShhoocckkss00
TTiirreess aanndd IInnsseerrttss44
BBooddiieess55
Chassis Set-up 15
TTrraacckk--wwiiddtthh55
DDoowwnnssttooppss66
RRiiddee HHeeiigghhtt88
AAnnttii--rroollll BBaarrss88
AAcckkeerrmmaann aanndd SStteeeerriinngg TThhrrooww SSyymmmmeettrryy22
FFrroonntt AAnnttii--ddiivvee2222
CCaasstteerr AAnnggllee2233
DDrriivviinngg ccaammbbeerr2233
TTooee--iinn && TTooee--oouutt2255
RReeaarr AAnnttii--ssqquuaatt2266
WWhheeeellbbaassee2277
CChheecckkiinngg ffoorr SSuussppeennssiioonn TTwweeaakk2299
Chassis Balancing 31
Maintenance & Tips 3
Contents:
21

When adjusting the servo, the steering must be adjusted so that the steering
block does not hit the pivot balls. If it does, decrease steering throw with your
radio's EPA setting, or with the dual-rate setting if EPA is not available. Failure
to do so can greatly reduce the life of your servo and influence the racing
performance.
SPEED CONTROL ADJUSTMENT
Set up the speed control according to the manufacturer's directions.
NOTE: Some manufacturers require the motor to be connected during
adjustment.
CONNECT THE MOTOR
Elevate the T on a stand so that all four wheels can spin without touching
anything. Switch the power on again. Check the speed control and steering
settings once again to make sure they work properly. When finished, turn the
power off and disconnect the batteries.
BATTERY AND SPEED CONTROL PLACEMENT
The speed control position depends on the position of batteries.
The T EVO2 allows you to position the batteries forward
or rearward on both sides of the chassis (3+3 saddlepacks),
place all six batteries along one side of the chassis, or use
6-cell stick packs. The position of the batteries will
change the handling characteristics of your car.
Final Adjustments
CHASSIS PREPARATION
XRAY has already taken the extra
step of sanding the edges of the
upper and lower chassis plates so
they are smooth before shipping
them. You might want to take it even
further by sealing the outer edges of
the lower chassis plate with
cyanoacrylate (CA) glue, though this
is not necessary, since the specially-
designed overlapping nylon front
bumper protects the leading edge of
the chassis from abrasion. Put a drop
of thick CA on a cotton swab and
apply it to the edge of the chassis.
Make sure not to let any excess glue drip on the surfaces of the chassis plate.
Slowly work your way around the whole outer edge.
The battery cutouts in the T EVO2 chassis were designed to fit the latest
2400mAH and 3000mAH batteries. However, if you used excess glue when
assembling your saddle packs they might not fit properly. File the edges of
the battery cutouts at a 45-degree angle but be sure not to sand so much
that the batteries sit below the bottom of the chassis.
RADIO ADJUSTMENTS
First, remove the servo horn from the steering servo, and disconnect the
motor wires (be sure not to let the motor wires short circuit), then turn the
transmitter on. Next, connect the battery pack and turn on the power switch
on the speed control. Set the steering trim to neutral on your transmitter, then
reconnect the servo horn so that it is leaning in
slightly towards the center line of the chassis.
Now that the steering servo is centered, use the
transmitter to turn the steering left and right,
noting if the wheels are moving in the proper
direction. If not, change the steering servo
direction (servo reverse) on the transmitter and
re-center the servo horn if necessary.
Next examine the T 's servo saver. Use the
steering link adjustment to get the servo saver
as centered as possible.
Next examine the front wheels. Make sure that
they are pointing straight ahead. If not, adjust
the two steering rods equally until the wheels
point straight ahead.
90°
Final Adjustments
.. RREEAARR
Batteries are placed in rear
= more rear traction, less steering.
22.. CCEENNTTEERR
Batteries are placed in the middle
= slightl more steering than full rear
slightl less rear traction than full front.
33.. FFRROONNTT
Batteries are placed in front
= less rear traction, more steering.
44.. AALLOONNGGOONNEE SSIIDDEE
Batteries are placed along one side.
Use when track la out has a high
percentage of corners turning one
direction or use for oval racing. Make
sure to balance the car using
additional weights on the other side of
the chassis, if required. Note: It ma be
more difficult to balance the car.
55.. SSTTIICCKKPPAACCKKSS
Use the optional #306170 Stick Pack
Holder to use 6-cell stick packs.
4
3

DIFFERENTIAL ADJUSTMENT
Differentials allow the wheels at
opposite ends of the same axle to
rotate at different speeds. Why is this
important? When a car turns in a circle, for
example, the outer wheel has a larger
diameter circle to follow than the inner wheel. The outer
wheel must travel further than the inner one in the course
of the circle, so it needs to rotate faster to keep up. If the
differential is too tight, the result is that the wheels "fight" each other for the
proper rotation speed; the result is a loss of traction.
• For optimal performance, the rear differential should be as free as possible,
with minimal slippage.
• When the front differential is looser than the rear one, steering response
will increase.
• When the front differential is tighter, steering response decreases, but there
is more stabilit in the turns.
• A tighter rear diff will make the car understeer slightl into the corner, but
it will make the car more difficult to control out of the corner (powerslides).
• Make sure that neither diff slips under power, as this will cause power
loss and excessive wear.
• On ver high traction surfaces, the diffs can be adjusted tighter for better
response.
BBuuiillddiinngg tthhee ddiiffffeerreennttiiaallss::
When you build a differential, DO NOT tighten it fully; build the diff and
tighten very gently. If you overtighten the diff initially, the diff balls will mar
the surface of the diff plates and the diff balls and plates will become
damaged. For exceptionally smooth operation and long diff life, we advise
that you use the XRAY Carbide Diff Balls #30509 .
Tighten the diff until you feel some resistance. To check the diff, hold both
wrenches in one hand and try to rotate the pulley. It should take some force
to get the pulley to slip between the two outdrives. Then remove both
wrenches and rotate one of the diff halves while holding the pulley stationery.
The action should feel smooth. If it doesn't, loosen the diff screw / 6 to /8
of a turn. Final adjustment will be made with the diff in the car and on the
track.
BBrreeaakkiinngg iinn tthhee ddiiffffeerreennttiiaallss::
Differentials must be broken in properly in order to operate properly. When
breaking in the diff, the balls create a groove in the diff rings; this is normal
and essential for proper operation. If you tighten the diff fully the first time
you build it, the ball will not create a proper groove, and will become
damaged. After the car is completely assembled, run the car for few minutes,
then tighten each diff a little bit. Repeat this several times to break in the diff
and set the correct tightness.
Final Adjustments
RECEIVER PLACEMENT
You have several options for mounting the receiver. The location will depend
on the battery and speed control positions. Choose the location that provides
the best weight distribution on your car. Use double-sided tape to mount the
receiver.
NOTE: Depending on where ou mount the receiver, ou can install
the antenna mount in two different places on the chassis.
MOTOR GEARING
To get maximum performance from your motor, proper gearing is critical.
The gear ratios listed in the chart are the recommended starting gear ratios.
Ratios can vary from track to track, but what we list is a good starting point
for your tuning. Remember not to change pinions more than one tooth at a
time, and that overgearing can damage your motor.
CCAAUUTTIIOONN:: EExxcceessss hheeaatt ccaauusseedd bb oovveerrggeeaarriinngg ccaann ddeessttrroo oouurr mmoottoorr..
NOTE: There should be just a tin amount of pla between the
p
inion teeth
and the spur teeth.
Final Adjustments
diff pulley 34T / one way pulley 16T
drive ratio 2.125 : 1
Overall Gear Ratio Chart pit h 1/48”
87 90 93 96
20 10.20
21 9.71
22 8.98 9.27
23 8.59 8.87
24 8.23 8.50
25 7.65 7.91 8.16
26 7.36 7.60
27 7.08 7.32
28 6.60 6.83 7.06
29 6.38 6.59
30 6.16 6.38
31 5.96 6.17
32 5.78
33 5.60
34 5.44
Overall Gear Ratio Chart pit h 1/64”
116 120 124 128
27 10.07
28 9.71
29 9.09 9.38
30 8.78 9.07
31 8.50 8.77
32 8.23 8.50
33 7.73 7.98 8.24
34 7.50 7.75
35 7.29 7.53
36 7.08 7.32
37 6.66 6.89 7.12
38 6.49 6.71
39 6.32 6.54
40 6.16 6.38
41 6.01 6.22
42 5.87
43 5.73
44 5.60
45 5.48
pinion spur g. pinion spur g.
6
5

wrench into the hole. Rotate the rear
left wheel until the wrench goes all
the way through.
With the wrench in place, rotate the
rear left wheel bbaacckkwwaarrddss ((++))to
ttiigghhtteennthe diff. To lloooosseennthe diff,
rotate the rear left wheel ffoorrwwaarrddss ((--)).
Tighten or loosen the diff only in /8
turn increments, checking the diff
tightness with each adjustment.
The initial setting should be that the differential action is smooth, but tight
enough so that it takes high effort to rotate the left wheel when the right one
and the spur are held tight. Run the car for approximatel one minute. Then
recheck the diff adjustments b again
following the steps above. Your diffs
should be read .
Hint: The chassis is designed so that
you can very easily adjust the
tightness of the differentials without
taking the body off. Just turn the car
over and adjust the differential from
the bottom of the chassis.
ONE-WAY PULLEY ADJUSTMENT
The one-way pulley allows the front wheels to spin independently from the
rear wheels. Our unique one-way system lets you determine how freely the
front wheels spin. The plastic locknut on the spur layshaft can be fully
tightened to lock the front wheels to the rear (full-time 4WD) or loosened to
let the front free wheel off power (4WD on throttle, RWD off throttle). Or it
can be set somewhere in between to match your driving style.
.. LLoooosseenneedd oonnee--wwaayy ppuulllleeyy
The main effect of the loosened one-
way is more off-power steering.
However, it should only be used on
high traction surfaces or large tracks
where minimal braking is required;
since only the rear wheels are used
for braking, spins induced by a
locked rear tire are more likely. One
of the benefits of a loosened one-
way pulley is less drive train drag at
maximum speed. This can increase
top speed.
AAddjjuussttiinngg tthhee ffrroonntt ddiiffffeerreennttiiaall::
Place the car on the table with the
front end pointing towards you. To
check front diff tightness, hold the
spur gear with your right hand and
hold the left front wheel against the
table with your right forearm, and try
to rotate the front right wheel with
your left hand bbaacckkwwaarrddss. If the front
right wheel rotates too easily, you
need to tighten the front differential.
The diff output shaft on the left side
of the car has a hole in it. Place a
small hex wrench into the hole.
Rotate the front right wheel until the
wrench goes all the way through.
With the wrench in place, rotate the
front right wheel ffoorrwwaarrddss ((++))to
ttiigghhtteennthe diff. To lloooosseennthe diff,
rotate the front right wheel
bbaacckkwwaarrddss ((--)).
Tighten or loosen the diff only in /8
turn increments, checking the diff
tightness with each adjustment.
The initial setting should be that the
differential action is smooth, but tight
enough so that it takes high effort to
rotate the right wheel when the left
one and the spur are held tight.
AAddjjuussttiinngg tthhee rreeaarr ddiiffffeerreennttiiaall::
Place the car on the table with the
rear end pointing towards you. To
check rear diff tightness, hold the
rear right wheel and the spur gear
with your right hand, and try to rotate
the rear left wheel with your left
hand. If the rear left wheel rotates
too easily, you need to tighten the
rear differential.
The diff output shaft on the right side
has a hole in it. Place a small hex
Final Adjustments Final Adjustments
8

SHOCKS
Shocks, or shock absorbers, are
a part of the suspension that
allow the wheels to keep as
much contact with the running
surface as possible. Damping,
mounting position, spring
tension, and spring preload
are all characteristics that
determine how the shock
performs.
SShhoocckk sseettttiinnggss::
The T EVO2 features unique 4-step externally adjustable racing shocks that
do not require you to change pistons or change the oil to alter the damping.
Initially, the damping should be set separately for the front and the rear so
that the car quickly settles when dropped from approximately 5 cm (2"). For
our initial settings, if it bounces before settling, it is too stiff. If it slaps the
table, it is too soft.
•• SSoofftt ddaammppiinnggwill produce most grip (both front and rear) through chassis
roll, but this will also decrease the cornering speed.
•• HHaarrdd ddaammppiinnggwill make the car break traction more easil , but with less
chassis roll and higher cornering speed.
SSpprriinnggss::
The shock springs support the weight of the car. Different spring tensions
determine how much of the car's weight is transferred to the wheel relative to
the other shocks. The spring tension also influences the speed at which a
shock rebounds from compression.
Spring selection depends on the whether the track is fast or slow, or has
high or low traction.
••SSttiiffffeerr sspprriinnggss::Makes the car feel more responsive, more direct. The car will
react faster to driver input. Stiff springs are suited for tight, high-traction
tracks that aren't too bump . Usuall when ou stiffen the whole car, ou
lose a small amount of steering. Stiffer springs reduce chassis roll.
••SSoofftteerr sspprriinnggss::Better for bump and ver large and open tracks. The can
also make the car feel as if it has a little more traction in low-grip
conditions. Springs that are too soft make the car feel sluggish and slow.
Softer springs allow more chassis roll.
••SSttiiffffeerr ffrroonntt sspprriinnggss::The car will be more stable, but will have less front
traction and less steering. It will be harder to get the car to turn, the turn
radius will be bigger. The car will have a lot less steering exiting corners.
On ver high-grip tracks, if the track itself feels tack or stick , ver stiff
springs are preferred.
••SSoofftteerr ffrroonntt sspprriinnggss::The car will have more steering, especiall in the middle
and exit of the corner. Front springs that are too soft can make the car
oversteer.
Final Adjustments
To let the front wheels freewheel, hold the locknut securely with pliers, then
rotate the spur gear backwards. The locknut will back away from the fixed
pulley and move towards the left bulkhead.
NOTE: Pull the fixed pulley away from the one-way pulley to let the front belt
move freely without binding.
22.. TTiigghhtteenneedd oonnee--wwaayy ppuulllleeyy
The pulley should be tightened under
slippery conditions, if you need to
lessen steering, or if heavy braking is
needed.
To tighten the one-way pulley, hold the
locknut securely with pliers, then rotate
the spur gear forwards. The locknut
will tighten the fixed pulley and move
towards the right bulkhead.
ONE-WAY FRONT DIFFERENTIAL (available option)
What is the difference between the one-way pulley
and the optional one-way diff?
The one-way pulley allows differential action under
acceleration. That means that when going through a
turn on throttle, if the inside wheel breaks traction, it
can still "unload" and prevent the outer wheel from
getting any power. The optional front one-way
differential (#30 5 00) gets around this problem by giving each wheel its
own independent one-way bearing. This way, the two wheels can rotate at
different rates, like with a regular differential, but on throttle, if one wheel
looses traction, the other one still gets power to pull the car through the turn.
Keep in mind that when using the one-way pulley with a loose setting or
when using the one-way differential, no drag brake should be used. Most
racers will also find it more convenient to set their radio to give less braking
action (use the throttle EPA setting); this will prevent the rear tires from
locking unexpectedly.
Use table below as a general guideline for the use of the one-way pulley and one-way differential.
TRACK SURFACE ONE-WAY PULLEY ONE-WAY FRONT
LOCKED LOOSENED DIFFERENTIAL
Low tra tion
Medium tra tion
(slow, tight orners)
High tra tion
(slow, tight orners)
High tra tion
(fast, sweeping orners)
✔
✔✔
✔✔
Final Adjustments
10
9

UUppppeerr ppoossiittiioonnss -- ffrroonntt sshhoocckkss::
There are three upper shock
mounting positions to choose from
on the front shock tower.
Initial setting:
Front shocks: position #2
UUppppeerr ppoossiittiioonnss -- rreeaarr sshhoocckkss::
There are numerous upper shock
mounting positions to choose from
on the rear shock tower.
•• TToopp rrooww ooff hhoolleess:: use with Serpent
shocks (longer)
•• MMiiddddllee rrooww ooff hhoolleess:: use with
larger tires and XRAY shocks
(shorter)
•• LLoowweerr rrooww ooff hhoolleess:: use with
smaller tires and XRAY shocks
(shorter)
Initial setting:
Rear shocks: position #7
LLoowweerr ppoossiittiioonnss -- rreeaarr sshhoocckkss::
There are three lower shock mounting positions to choose from on the rear
lower arms.
•• OOuuttssiiddee ppoossiittiioonn ##33:: Harder
damping - less grip but lower
chassis roll. Stabilit is decreased,
but high-speed cornering, traction
permitting, is increased.
•• MMiiddddllee ppoossiittiioonn ##22::Optimum
position for most tracks.
•• IInnnneerr ppoossiittiioonn ##11::Softer damping -
higher stabilit . Traction is
increased, but so is chassis roll; not
good for fast corners.
Initial setting:
Rear shocks: middle position (#2), both rear arms.
LLoowweerr ppoossiittiioonn -- ffrroonntt sshhoocckkss::
There are three lower shock mounting positions to choose from on the
front lower arms.
••OOuuttssiiddee ppoossiittiioonn##33: More stable, less steering. With the front suspension
stiffer, there is more stabilit .
••MMiiddddllee ppoossiittiioonn##22: Optimum position for most tracks.
•• IInnnneerr ppoossiittiioonn ##11: softer damping, better steering. As the front suspension
gets softer, more traction is taken awa from the rear, causing the car to
lose stabilit .
Final Adjustments
••SSttiiffffeerr rreeaarr sspprriinnggss::Rear traction is reduced. The car will have more steering
in the middle and exit of the corner. This is especiall apparent in long,
high-speed corners.
••SSoofftteerr rreeaarr sspprriinnggss::Rear traction is increased in corners as well as through
bump sections and while accelerating.
SSpprriinngg pprreellooaadd::
Adjust the spring collar on the shocks so that the springs are only slightly
compressed when the car is fully equipped, ready-to-run. Spring preload
should only be used to alter ride height. It is advised to change to a softer or
harder spring to change the
characteristic of the springs, rather
than fully loosening or tightening the
standard included ones.
Hint: File a small notch on the top of
each spring collar so you can tell
when you have adjusted it one full
rotation.
SShhoocckk ppoossiittiioonn::
The upper and lower shock mounting points determine how much leverage
the lower suspension arm has on the shock when compressing it, and the
progressiveness of the suspension. The different settings change how the
shock reacts to compression.
•• SShhoocckkss mmoorree iinncclliinneedd::More progressive, smoother feel and more lateral
grip. Having all shocks inclined makes the car ver eas to drive, and it
feels like the car has more grip, but it's not alwa s fastest.
••SShhoocckkss mmoorree vveerrttiiccaall::More direct feel, but less lateral grip (side-bite).
••FFrroonntt sshhoocckkss mmoorree iinncclliinneedd tthhaann rreeaarr sshhoocckkss:: Steering will feel ver smooth
and there will be a little more mid-corner steering. Mounting the rear
shocks ver upright can result in the rear feeling unpredictable and more
nervous in turns.
••RReeaarr sshhoocckkss mmoorree iinncclliinneedd tthhaann ffrroonntt sshhoocckkss::The car will feel aggressive
turning in, but most of the time the car have a little less steering. The car
will have a lot of side traction in the rear, and turning radius won't be ver
tight.
123
Final Adjustments
VVIIOOLLEETT
medium
(#30 8396)
PPUURRPPLLEE
medium-hard
(#30 8397)
RREEDD
hard
(#30 8398)
BBLLUUEE
soft-medium
(#30 8395)
YYEELLLLOOWW
super-soft
(#30 8393)
WWHHIITTEE
soft
(#30 8394)
XXRRAAYY sspprriinngg tteennssiioonnss::
12
11
123
6
12345
11
12
13 14 15
78910

OOiill::
••TThhiicckkeerr ooiill- slower shock action -- slower chassis
weight transfer from side to side or front to rear.
In general, the slower shock action means less
traction, but the slower weight transfer means the
car is less likel to get unsettled with sharp
direction changes, like chicanes.
••TThhiinnnneerr ooiil - faster shock action -- faster chassis
weight transfer. Faster shock action means that
the suspension can work faster to keep the tire in
contact with the surface quicker; that means more
traction. But it also means the chassis is more
susceptible to chassis roll and getting unsettled in
sharp direction changes.
Keep in mind that thicker oil will require the use of heavier springs to
compensate for the heavy damping action. Likewise, thinner oil requires
lighter springs.
Pistons:
••LLeessss ppiissttoonnss ooppeenn:: acts much like using thicker oil.
••MMoorree ppiissttoonnss ooppeenn::acts much like using thinner oil.
TIRES & INSERTS
Tires and inserts are probably the most important factors in getting the best
performance from your car; getting them right is the first thing you should
do. When you arrive at the track with a basic car set-up, select the best tires
and inserts for your track, then fine-tune your set-up. Check with the other
racers who frequent your track for a good starting point. As a general
guideline, use treaded or radial pattern tires on dusty or unprepared
surfaces, and use slicks on high-traction prepared surfaces.
Here are a few basic rules: Select the rubber compound according to the
track temperature. Higher temperatures usually require harder compounds.
Firm inserts are better for quick direction changes, since they'll scrub off less
speed in high-speed chicanes. Soft inserts give a little more grip, and they
also make the car easier to slide: the difference between gripping and
slipping (one end sliding out) isn't as harsh. Soft inserts allow you to 'throw'
the car into the corner, and they probably make the car easier to drive.
Sponge-type inserts are much lighter, (less rotating mass means quicker
acceleration), but they don't retain heat as well. So it's more likely that the
tires will overheat towards the end of the race. Molded inserts are heavier,
but they retain heat better.
Regularly rotate your tires from side to side for even wear. If the same
compound and inserts are used on all four corners, then rotate front to rear
as well.
Final Adjustments
NOTE: Never use the lower of the
two holes that are on top of each
other in the outer position. Use of
the lower hole will severel restrict
the front end ride height.
Initial setting:
Front shocks - middle position (#2),
both front arms.
SShhoocckk aabbssoorrbbeerr ddaammppiinngg::
Shock absorber damping influences the responsiveness of the chassis during
cornering, and helps to maintain proper contact between the tire and the
road surface during vertical movement. Setting the right damping is therefore
always a compromise and requires a lot of "hands on" experience.
No shock damping means that the spring rate determines how long it takes
for the spring to compress and the suspension to reach a stable position.
Damping only comes into play when the suspension is moving, and loses its
effect when the suspension has reached a stable position. When the spring
is compressed or decompressed, the shock absorber oil resists this
movement. The two factors that determine the speed at which the shock
reacts are the thickness of the oil and the piston valving (the number of holes
in the shock piston the oil passes through).
DDaammppiinngg aaddjjuussttmmeenntt::
Disconnect the lower shock mount
from the arm. Fully extend the shock
rod and turn it slightly to lock the
piston in the shock body.
• Turning the shock rod fully CCCCWW
aligns 4 holes in the pistons =
ssoofftteesstt ddaammppiinngg.
• Turning the shock rod fully CCWW
aligns only hole in the pistons =
hhaarrddeesstt ddaammppiinngg.
The XRAY adjustable shocks have 4
settings, each of which can be felt by
a little "click".
Initial settings:
Front shocks: 2 holes open (medium)
Rear shocks: 4 holes open (lightest)
Final Adjustments
43
2
1
FULLY EXTEND THE SHOCK ROD
123
14
13

SSeettttiinngg RReeaarr TTrraacckk--wwiiddtthh::
We recommend that you DO NOT change the rear track-width, otherwise it
would decrease the stability of the car. But if necessary, you can change the
trackwidth to accommodate different wheels with different offsets.
Initial setting:
Rear Track-width: 189mm
DOWNSTOPS
Downstops limit how far the suspension arms travel downward, which
determines how far upwards the chassis rises. The amount of downward
suspension travel affects the car's handling, as it directly impacts the weight
transfer of the chassis. Restricting upward chassis travel (more downstop)
reduces the weight transfer of the chassis, making the car more stable.
Allowing more upward chassis travel (less downstop) increases the weight
transfer of the chassis, making the car more responsible but less stable; it is
also better on a bumpy track. The effect may change with the type of track
and/or amount of grip available. It is very important to adjust the downstops
such that the left and right sides are equal. Downstops are checked with the
chassis elevated above a reference surface.
Hint: Use Hudy Set-up Board and Droop Gauge Tool.
Perform these initial steps:
. Remove the wheels from the car. Disconnect anti-roll bars if mounted.
2. Place the # 0 7702 support blocks on the reference surface, then place
the chassis on the elevating blocks.
BODIES & AERODYNAMICS
Aerodynamics play an important role in the performance of the car. One
body may simply work better than another body. Aerodynamic effects are
more apparent at high speeds, and have little influence in slow corners.
In general, blunt-nosed bodies are more stable, and have less steering than
bodies with a sloped nose. Another important consideration is the rear wing.
The higher it's mounted, and the bigger it is, the more rear downforce it will
generate. A body with high downforce will help the car get lots of traction
throughout the turns. But high downforce usually comes at the expense of
drag, so the car may not be the fastest on a long straightaway.
Experiment with bodies that have different frontal areas and different wing
shapes to find the one that works best for you. Like most other tuning
parameters, body style is also a compromise. Experiment to find out what
bodies work best at your track.
TRACK-WIDTH
Front track-width affects the car's
understeer and steering response.
Increasing track-width will result in more
understeer, while decreasing it will result
in less understeer and faster steering
response.
The track-width is measured on the
outside of the wheels.
It is important that the track-width is
adjusted symmetrically, meaning that
the right and left wheels must be the
same distance from the center-line of the
chassis.
Hint: Use the Hudy Set-up Board with
Set-up Board Decal nicely marked with
mm grid.
SSeettttiinngg FFrroonntt TTrraacckk--wwiiddtthh::
Turn both pivot balls IN equally to reduce track-width, turn them both OUT
equally to increase track-width.
Remember to reset the front toe setting by adjusting the lengths of the
steering rods equally to compensate for the width adjustment.
Initial setting:
Front track-width: 189mm
Final Adjustments
TRACK WIDTH REAR
TRACK WIDTH FRONT
Chassis Set-up
Chassis Set-up
16
15

RIDE HEIGHT
This describes the height of the chassis in relation to the surface it is sitting
on. This adjustment must be made with the chassis ready-to-run but with no
body. The shock preload collars are used for raising and lowering the ride
height.
Perform these initial steps:
. Prepare the car ready-to-run, without body.
2. Place the car on Hudy Set-up Board and use # 0 77 5 Ride Height
Gauge to measure the ride height in front and rear.
Use the shock preload collars to
raise or lower the ride height.
Initial settings:
Front ride height: 5mm
Rear ride height: 6mm
Try using a slightly lower ride height
for high traction conditions, such as
carpet racing.
AANNTTII--RROOLLLL BBAARRSS ((aavvaaiillaabbllee ooppttiioonn))
Anti-roll bars are used to stabilize the car from excessive chassis roll (which
occurs when the car leans through the turns by centrifugal force).
Anti-roll bars are generally used on smooth, high traction track conditions. If
the conditions are very bumpy, then anti-roll bars are probably not necessary.
NOTE: Anti-roll bars adjustment is performed with disconnected shocks.
Chassis Set-up
FFrroonntt ddoowwnnssttooppss::
Using the # 0 77 2 measuring
gauge, measure the distance from the
reference surface to the bottoms of the
steering blocks. Positive numbers
indicate the distance (in mm) ABOVE
the level of the support blocks (or,
above the bottom of the chassis).
Negative numbers indicate the
distance (in mm) BELOW the level of
the support blocks (or, below the
bottom of the chassis).
Adjust the front downstop screws so
that the bottoms of the steering
blocks are at the recommended
setting on the gauge.
Initial setting: 2 mm on gauge.
(Actual measurement = 2 mm above
the level of support blocks).
The downstops depends on the
diameter of tires and track condition.
The above setting was for smaller tires
(approx. 63 mm) and a smooth track.
RReeaarr ddoowwnnssttooppss::
Adjust the rear downstop screws so
that the bottoms of the rear uprights
are at the recommended setting on
the gauge. Note that the REAR pivot
ball hole should be used for
downstop measuring.
Initial setting: 6mm on gauge.
(Actual measurement = 6mm above
the level of support blocks).
The downstops depends on the
diameter of tires and track condition.
The above setting was for smaller
tires (approx. 63 mm) and a smooth
track.
Also, if you have too much steering
while coming into corner off throttle
or while braking, try adding mm to
the rear downstop setting. This will
cut down on the amount of weight
that is transferred away from the rear
tires when off the throttle.
Chassis Set-up
RIDE HEIGHT FRONT RIDE HEIGHT REAR
18
1