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FUEL for the gas engines is available at any full service hobby shop. It is highly recommended that you use only O'Donnel
or Blue Thunder fuels. Although there are many other fuels available, these two have been tested extensively and have proven to
consistently produce the best results. Another common mistake that newcomers will make is to use a fuel with too high of a nitro
content. Many enthusiasts think that the more nitro, the faster the truck will go. This statement is true to a certain extent, but we
have found that anything above 20% is really just a waste of time (and money!).
BALL BEARINGS are the single biggest improvement that you can make to your new GTX truck if you are running the
version that comes with bushings (A-0951). Bearings will increase the life of many of the transmission gears as well as some of
the clutch parts.
CAMBER in the front end of the truck is not really changed much. In the front, we will run between one and two degrees of
negative camber at ride height. A general rule of thumb is that more negative camber will help the truck go through bumps in
turns a little more consistently. Less negative camber can make the truck respond quicker on some tracks with hard packed
surfaces.
The rear camber is used to help the truck drive through bumps in corners a little better. Generally, we will run between one
and three degrees of negative camber at ride height. More negative camber will make the truck drive through bumps better, but
you will usually lose a little straight line rear traction.
FRONT TOE-IN and TOE-OUT is fully adjustable by changing the length of the tie rods. When adjusting this, be sure to
adjust both tie rods equally so that the steering balance from left to right will remain the same. Toe-out will make the truck turn
into the corner faster, but can cause oversteer. It can also make the truck feel "wandery" exiting corners and cause the truck to
hook.
Toe-in makes the truck a little easier to drive, and will make the truck more neutral feeling and more stable exiting corners.
We almost always run about one degree of toe-in on the GTX truck.
FRONT RIDE HEIGHT is an adjustment that can change the way a truck jumps, turns, and goes through the bumps. This
is an adjustment that can vary from track to track. You should try raising and lowering the front ride height to get a feel for what
it does to the handling of the truck. The front ride height should initially be set so that the arms are level at ride height. To set the
ride height, drop the front of the truck from about 2-3 inches above the table. Lightly "work" the front suspension up and down.
This will"settle" the front suspension at its natural ride height. "Working" the suspension becomes important as the parts start to
get dirty and worn from running.
Once the suspension has settled, the arms should be level. If the front end is either too high, or too low, adjust the spring
collars accordingly and check the ride height again as described above. Continue this procedure until the front ride height is
adjusted to the desired location.
REAR RIDE HEIGHT can change the way a truck turns, the amount of traction a truck has, and the way a truck goes
through the bumps. Again, it is a good idea to play with this adjustment and get a feel for it. For most conditions, the rear ride
should be set so that the dog bones are level. Adjust the rear ride height in the same way as described in the front ride height
section.
CAMBER LOCATIONS on the GTX are very adjustable. Although there are many holes to choose from, it is suggested that
the locations in the manual be used. We have done extensive testing with all ofthese locations both on the track, and on special
computer programs, and have found the locations in the manual to be vel}' consistent from track to track. These locations should
produce the best all around setup and work under all conditions.
REMOVING THE ENGINE can seem slightly difficult when you look at all of the fuel lines and linkages connected to the
engine. This is really a simple thing to do though. The easiest procedure that we have found is the following: First, remove the
fuel line from the carburetor. Remove the 'E'-clip from the bottom of the throttle pivot and remove the throttle pivot from the servo
horn. Loosen the screw in the rear of the center chassis brace (the screw that doesn't pass through the engine mount). Loosen
the two forward screws in the transmission. Remove the four screws that hold the engine mounts in place. Slide the engine out
of the left side of the chassis. To reinstall the engine, simply reverse these steps.
WORKING ON THE CLUTCH can also seem tough at first. If you only need to work on the clutch, and don't need to
remove the engine, follow this procedure: Remove the slipper adjustment nut and all of the slipper parts from the top shaft.
Remove the spur gear, gear plate, and slipper pad. Remove the clip from the clutch nut. Remove the clutch nut spacer and the
outside bearing (or bushing) from the clutch bell. With the outside bearing (bushing) removed you should be able to rotate the
clutch bell slightly so that it can slide off, past the throttle servo. When you are finished working on the clutch, install the clutch
bell without the outside bearing (bushing). Once the clutch bell is in place, install the outside bearing (bushing), followed by the
clutch nut spacer. Attach the clutch nut clip. Assemble the slipper assembly according to the manual.
The suggestions in this section are only general guidelines. There are so many variables in a racing truck that they can't
possibly be listed in a simple tip section. Go to the track, try various combinations of setups, and get a feel for what each one
does to
_t~e
handling. Look for setup updates as well as the latest hot tips in "Tech-Talk" each month in R/C Car Action Magazine.
Good luck with your new GTX. We're sure you will be pleased with it's superb performance.
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