NITRO 4-TEC 3.3
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31
ADJUSTING YOUR NITRO 4-TEC 3.3
At no time should the body
of the model strike the
ground or interfere with
the suspension or tires.
Either situation will cause
extremely unpredictable
handling.
Toe-in
Set the steering trim on your transmitter to neutral. Now, adjust your
tie rods so that both wheels are pointing straight ahead and are
parallel to each other (0 degrees toe in). This will ensure the same
amount of steering in both directions. If you run out of adjustment,
then the steering servo may have to be re-centered (see Centering the
Servos on page 34).
Fine Tuning the Shocks
The four shocks on your Nitro 4-Tec have the
most influence on its handling. Whenever
you rebuild your shocks, or make any
changes to the pistons, springs or oil, always
do it carefully and in pairs (front or rear).
Piston head selection depends on the range
of oil viscosities that you have available.
For example, using a one-hole piston with
a lightweight oil will give you the same
dampening as a two-hole piston with heavier
oil. We recommend using the one-hole
pistons with a range of oil viscosities from
10W to 50W (available from your hobby
shop). The thinner viscosity oils (30W or less)
flow more smoothly and are more consistent,
while thicker oils provide more dampening.
Use only 100% pure silicone shock oil to prolong seal life.
The ride height for Nitro 4-Tec can be adjusted by adding or removing
the clip-on spring pre-load spacers. Instead of adding spacers to
increase stiffness, use stiffer springs. Adjust the ride height so that the
suspension arms are slightly above being parallel to the ground. Note
that changes in ride height will occur when the changes in damper
angle or spring rates are made. You can compensate for ride height
changes by changing the pre-load spacers on the dampers. Generally
speaking, ride height should be set as low as possible without causing
significant bottoming of the chassis. Also, in order not to disturb
cornering balance, front and rear tire height diameters should be
equal. Replace excessively worn tires.
Belt Tension Adjustments
The Nitro 4-Tec’s front and middle drive
belts are designed to have a high initial
tension. During the break-in period, the
drive belts and pulleys will “wear in” and
the belt tension will gradually decrease.
The front and middle belt tensions can
be tightened by inserting shims under
the front bearing block. Do not tighten
the front belt tension unless there is
more than 0.25 inch (6mm) deflection
at the center of the belt (see drawing).
To tighten the belt, add the 0.1mm shim
first and retest. If the belt is still loose,
remove the 0.1mm shim and add the
0.2mm shim and retest.
The rear belt tension is
adjustable via belt tension
cams in the right and left
rear side plates. The rear
belt in the Nitro 4-Tec
transmits most of the
engine’s power. Because
of the high loading of
the rear belt, the tension
should be checked
every 3-4 hours (20-25 tanks of fuel) of running. If the rear belt can be
deflected more than 0.25" (6mm) (see illustration), the belt tension
cams should be rotated rearward to the next eccentric slot.
Left side plate
(Bulkhead)
Right side plate
(Bulkhead)
Rear of car
Rear of car
.25¨ (6mm)
Using Belt Adjustment
Shims
