30 • NITRO 4-TEC 3.3
ADJUSTING YOUR NITRO 4-TEC 3.3
It is important that your
engine is properly tuned and
has reached full operating
temperature before making
shift point adjustments. Stop
the engine before making
adjustments.
The transmission may not
shift if the adjustment screw
is turned too far in (locked
in first gear), or too far out
(locked in second gear). If the
model has quick acceleration
and does not appear to shift,
the transmission is never
reaching the shift point.
The shift point needs to
be lowered by turning the
adjustment screw counter-
clockwise. If the model
has poor acceleration but
very high top speed, the
transmission is shifting into
second gear almost instantly.
The shift point needs to
be raised by turning the
adjustment screw clockwise.
Once you become familiar with driving your Nitro 4-Tec 3.3, you may
wish to make adjustments for better driving performance.
Adjusting the Shift Point
The Nitro 4-Tec comes equipped with a two-speed transmission.
When the shift point on this transmission is adjusted correctly, it will
maximize acceleration, improve drivability, and minimize lap times.
Use a 2.0mm hex wrench to adjust the shift point.
1. Stop engine.
2. Rotate the drum until the access
hole is visible from the top.
3. Hold the spur gear set, and roll
the car forward while looking
through the access hole. Note
that you will see two set screws
through the access hole as you
roll the car forward. The first one
holds the two-speed mechanism
to the shaft. Do not loosen this
screw unless you want to remove the two-speed mechanism. The
second is the adjustment set screw. Refer to the drawing to identify
the screws.
4. Insert a 2.0 hex wrench through the
clutch drum and into the adjustment
set screw. (See diagram)
5. Turn the adjustment screw clockwise
to raise the shift point (later shifts).
Be careful not to overtighten the
adjustment screw or you may
damage the tension spring.
6. Turn the adjustment screw counter-
clockwise to lower shift point (earlier
shifts). Be careful not to loosen the
adjustment screw too much or you
may cause the screw and spring to fall out.
7. Use 1/8 turn increments to find the approximate, desired shift point.
8. Check performance by running a test lap after each adjustment.
9. Use 1/8-1/16 turn increments to fine tune the shift point.
ALIGNMENT SPECS
The Nitro 4-Tec is supplied with soft-compound, race-quality tires.
Due to the high power output of the TRX 3.3 Racing Engine and the
high performance nature of the tires, suspension alignment is critical
to achieving maximum tire life. Proper alignment promotes even and
consistent tire wear, as well as predictable and balanced handling.
Camber
The camber angle of both the front and
rear wheels can be adjusted with the
camber rods (upper turnbuckles). Use
a square or right-angle triangle to set
the camber accurately. Adjust the front
wheels to 0 degrees of camber (wheel
is perpendicular to the ground). In the
rear, adjust the wheels to 1 to 2 degrees
of negative camber. These adjustments
should be set with the car positioned
at its normal ride height. The following
information gives recommended stock
alignment settings for the Nitro 4-Tec with
stock tires and inserts.
Front Camber Degrees
-1.0
Rear Camber Degrees
-1.0
Front Caster Degrees*
12.0
Front Toe-In Degrees
0.0
* This setting is achieved by having the
1mm caster spacer in the front and the
2mm caster spacer in the rear (where
the upper suspension arm attaches to
the upper suspension arm mount).
Access
Hole
Drum
0
°
-1
°
-2
°
TO
0
°
0
°
0
°
-1
°
-2
°
TO
0
°
0
°
Front
Camber
Rear
Camber
