Advanced Tuning Adjustments; Suspension And Alugnment Settings; Caster Adjustment; Caster Angle And Bump Steer - Traxxas Revo 3.3 5309 Owner's Manual

Advanced Tuning adjustments

This advanced tuning guide will take you one step further into the cutting
edge technology that has been designed into Revo. Follow the instructions
provided here to take advantage of Revo'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 below:
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 (about 3/100 of a degree through
the entire range of travel). 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
42 • Revo 3.3
Caster adjustment shims (2 front, 2 rear)
10°
Ground plane
Number and Position of Caster
Adjustment Shims (Front Upper Control Arm)
In Front of Behind
Hinge Pin Boss Hinge Pin Boss
Caster
None Four
5.0°
One Three
7.5°
Two Two
10.0°
Three One
12.5°
Four None
15.0°
page 43, and look up your caster angle setting to find the correct position
for the outer toe links. Positioning the toe-links correctly will maintain the
original factory geometry and eliminate the unwanted steering angle
changes caused by bump steer.
Roll Center
There are two holes on the bulkheads
to mount each upper suspension arm.
The roll center of the vehicle can be
raised by mounting the upper control
arm in the lower of the two holes. This
will effectively increase the roll stiffness
of the vehicle (similar to installing
swaybars). Adding roll resistance to
one end of the vehicle will tend to add traction to the opposite end. For
example, increasing roll resistance in the rear by installing the upper arms
in the lower holes will provide more traction for the front wheels and
potentially more steering. Installing the upper arms in the lower holes on
the front and rear will increase overall roll resistance without changing the
handling balance. The arms are installed in the upper position from the
factory to make the truck easier and more forgiving to drive and less likely
to traction roll in turns. The lower holes should be reserved for track tuning.
Note: When the upper suspension arms are moved to the lower holes,
the front outer toe link ends and the rear toe control links should be
repositioned to eliminate bump steer. Refer to the Bump Steer Elimination
chart on page 43, and look up your suspension combination (caster angle
and roll center position) to find the correct position for the front outer toe
links and the rear toe control links. Adjustment is achieved using the shims
and hollow balls provided with the vehicle.
Rockers (Progressive Rate/ Suspension Travel)
One of the most exciting aspects of Revo'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 or
decrease the maximum wheel travel and also to change 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
Upper Control Arm
Upper Control Arm
Upper Mounting Holes
Upper Mounting Holes
Upper Control Arm Upper Control Arm
Lower Mounting Holes
Lower Mounting Holes