We know you want to win when you’re out at the track and as such, we try to share as many driving tips as possible. But, frequent winners know that winning ways start before the truck even hits the track. The first step in finding your way to the victory lane with your short course truck is in the build of the kit or the prepping of your RTR. Check out these tips and you’ll be well on your way to owning a truck that will help you win races.
The stock pistons, fluid and springs are always the best starting point. You’ll probably be tempted, but don’t change your kit’s baseline setup based on another driver’s suggestion or a pro driver’s setup sheet. It’s far more important that you build your shocks correctly than it is to find some black magic setup. It’s essential that you think of the shocks as pairs. The front shocks should be twins and so should the rear shocks. When comparing two shocks, say the fronts, you should ensure they are the exact same length when fully extended. When compressed without springs installed, they should extend the same amount when released. Lastly, they should extend at the same rate. A tool that is extremely useful when building shocks for racing is Losi’s Shock Matching Tool (item no. LOSA99170, $34).
Short course trucks frequently bottom out, so it’s essential that the bottom of the chassis is smooth. Most short course trucks use molded plastic chassis, but a few 4WD trucks use aluminum plates. The aluminum chassis plates are usually fine right out of the box, but molded plastic parts can have flashing and molding marks on the bottom of the chassis. These usually perfectly round marks are left from where the piece is pulled from the mold. These often have a rough surface in the circle that can be sanded smooth with a file. You can go one step further and add a smooth chassis protector to the bottom of your chassis. Companies such as Upgrade offer graphic chassis protectors for specific vehicles. Team Associated also offers chassis protector film you can cut to size (ASC9787, $9), as does JConcepts (JCI1155, $8). If you’re extremely serious about racing and want every advantage, another item to consider is removing the nerf bars to save some weight. They really do not protect the Lexan body and actually just wear the paint out faster where they rub the sides of the shell.
A painted and stickered body weighs a good amount and this component contributes to a high center of gravity. Mount the body as low as possible and protect the inside of the body where they tires may rub with some thin stickers. Make sure your wheel well openings are large enough that the tires are not rubbing. With the front suspension fully compressed, turn the front tires in both directions to make sure they do not hit the body. Also, open up the rear tailgate area as much as you can without destroying the look of the body.This will allow air to escape, but more importantly, will remove areas where flying dirt can get trapped and add weight to your truck. Next, use a body reamer to create holes for trapped air to vent and thus preventing the dreaded parachute effect. Most racers place a few holes on the hood right in front of the windshield and along the front fenders. Another place to make even larger vent holes is in the rear of the body in the area in front of the rear posts.
Tires are the most important aspect of setup. Make sure you have the right tread and compound for your track. Ask the fast guys and the track owner or race director. You do not have to run the same tire in front as you do in back. While that often works with a 4WD short course truck, 2WD trucks may benefit from having a less aggressive tire up front. For racing, one-piece rims are best. Bead-lock rims might look more realistic, but they add unneeded rotating mass. Make sure the bead is glued all the way around on each side of each tire and that the wheel nuts are properly tightened. This is especially true on wheels that mount directly on a drive pin where a slightly loose wheel can lead to a stripped out rim.
If your short course truck has non-pressed in drive pins on the axle, you a small dab of silicone glue on the pin. This will prevent it from falling out of the axle when the hex comes off, but the pin will still be easy to remove when needed. When building the drivetrain, make sure all bearings are properly seated. This is often overlooked and leads to a slow inefficient drivetrain.
Suspension and Steering
Always start with the manual’s baseline setup. Without the shocks installed, the suspension arms should move up and down freely and drop down when lifted under their own weight with no binding or hesitation. When you set the ride height, you want to run the truck fairly low unless the track is exceptionally rough. If your truck has no marks on the bottom after practice or a race, it’s too high. When assembling the steering bellcranks, tighten the screws down and then back them off slowly until the pieces move freely.
Wiring and Electronics
Short course trucks take a beating out on the track, so your electronics must be secure. If your receiver is in a radio box, you must wrap it in foam. The packaging used in the box your speed control came in is perfect. If your receiver is taped to the chassis use multiple layers of thick servo tape. The same goes for the speed control. Hard impacts and even constant vibrations can eventual damage these components. Next, make sure your wiring as neat as possible. There should be a slight amount of slack in the wires, but secure the excess wiring. The slack will ensure the wires aren’t pulled loose or stressed as the chassis flexes.
Before you worry about driving the perfect line or clearing the big triple-double jump, you need to make sure your truck is built right. These tips will help ensure you have a perfectly built racing machine that will allow you to drive to the best of your ability. Your equipment should always work for you, not against you; that is why proper building is so important.