Traxxas 59076-1 - Manual (Page 36)

36 • SLAYER PRO 4X4
This advanced tuning guide will take you one step further into the cutting
edge technology that has been designed into Slayer Pro 4x4. Follow the
instructions provided here to take advantage of Slayer Pro 4x4’s maximum
performance potential.
SUSPENSION AND ALIGNMENT SETTINGS
Caster Adjustment
The caster angle of the front suspension
may be used to adjust the understeer
(push)/oversteer handling characteristics
of the model. Generally, increasing the
caster angle will move the truck towards
an oversteer condition (more traction
on the front tires, less on the rear tires).
Decreasing the caster angle will create a
tendency towards understeer (pushing
in the turns). From the factory, the front
suspension is set to a caster angle of
10-degrees. The rear caster angle is not
adjustable. The caster angle of the front
suspension can be adjusted from 5° to
15°. Adjust the caster by positioning
the caster adjustment shims on
the upper control arms of the front
suspension as shown in the table to
the right.
Caster Angle, and Bump Steer
Bump steer is unwanted change in the
steering angle of the front wheels as the suspension travels up and down. It
can result in unstable and unpredictable handling. Bump steer is affected by
the position of the outer toe link end on the axle carrier. From the factory,
the toe links are positioned so that bump steer is virtually eliminated. When
the caster angle is changed, the outer toe link end should be repositioned
on the axle carrier to maintain zero bump steer geometry. Adjustment is
achieved using the shims and hollow balls provided with the vehicle. Refer
to the Bump Steer Elimination chart on page 37, and look up your caster
angle setting to find the correct position for the outer toe links. Positioning
the front toe-links correctly will maintain the original factory geometry and
eliminate the unwanted steering angle changes caused by bump steer.
In the rear, a small amount of bump steer can be used for advanced tuning.
On smooth surfaces, having the rear wheels toe-in slightly when the
suspension is compressed can add stability during hard acceleration. Refer to
the chart on page 37 for proper settings. Stock, the Slayer Pro 4x4 is setup to
increase rear toe-in during acceleration. Note that rear toe-out is not used.
Rockers (Progressive Rate/ Suspension Travel)
One of the most exciting aspects of Slayer Pro 4x4’s suspension is the
inboard shock (damper) arrangement that uses pivoting rockers to translate
vertical wheel travel into linear shock motion. The rockers can be changed to
increase the progressive rate of the suspension.
The progressive rate determines how much the force at the wheel
produced by the springs being compressed (wheel force) will vary with
suspension travel (or vertical travel of the wheel). On a progressive
suspension arrangement, the wheel force will increase at a faster and faster
rate as the suspension is compressed. It feels as though the shock spring
gets progressively stiffer the more you compress the suspension. On a
linear suspension arrangement, the wheel force increases linearly as the
suspension is compressed. The spring does not feel any stiffer, even when
the suspension is fully compressed. This provides a very “plush” feeling
suspension with seemingly bottomless suspension travel.
There are two different rocker arm sets that are compatible with Slayer
Pro 4x4. Both sets will allow the wheel to travel a total of 60mm in the
vertical direction. From the ride height position, the wheel will be able to
travel 40mm in the upward direction (bump), and 20mm in the downward
direction (droop). The Slayer Pro 4x4 comes equipped with the Progressive
2 rocker set, which offers a good balance of progressive rate for predictable
body roll, brake dive, and high-speed stability.
The Progressive 3 rocker arm set (available separately) uses a higher
progressive rate that will provide a firmer feel, reducing body roll, brake
dive and rear squat. Installation of the Progressive 3 rocker arm requires the
following parts:
#5359 Progressive 3 Rocker Arm Set
#5133 Pushrod Spacers (these are required to lengthen the pushrods to
maintain proper suspension travel.)
The chart below demonstrate the effect of the various rocker arms on wheel
force as the suspension
is compressed. On the
progressive rate, wheel
force is light at first
and increases as the
suspension is compressed.
Rocker Arm Total Travel Progressive Rate
Progressive 2
50mm
(35mm up / 15mm down)
Medium
Progressive 3
50mm
(35mm up / 15mm down)
High
Caster adjustment shims (2 front, 2 rear)
Vertical
Ground plane
10°
Caster
In Front of
Hinge Pin Boss
Behind Hinge
Pin Boss
5.0° None Four
7.5° One Three
10.0° Two Two
12.5° Three One
15.0° Four None
Number & Position of Caster Adjustment
Shims (Front Upper Control Arm)
ADVANCED TUNING ADJUSTMENTS
Constant
Rate Travel
Wheel Travel
Wheel Force
0
2
4
6
8
10
12
14
16
18
20
10 20 30 40 50 60 70 80 90
Progressive
Rate Travel