Weight distribution
Weight distribution is fairly straightforward - whichever wheel(s) have the most weight above them will get the most traction. Racing is dynamic, of course, and your car's weight will shift when it accelerates, brakes, and corners, and that is why it's important to have a well-balanced car, so one of those situations doesn't result in a complete loss of traction.
In short, if certain wheels of your car need more traction, you might be able to achieve that by shifting weight to those wheels. For instance, in low-grip dirt racing, it's common to have cars that are rear-heavy, thereby generating traction on the rear wheels that are needed to get the car moving. This will result in less grip for the front wheels, thereby forcing you to slow down and shifting weight to the front of the car, so you can get enough front grip to turn the car.
Ways to adjust your weight balance:
- Add weights. Many racers do this because they need to bring their cars up to minimum weight anyway, so they strategically place weights, typically on the chassis
- Use heavier parts. Many cars have options parts made of steel or brass rather than plastic or aluminum that will help bring up the weight of your car without adding to it. These option parts are typically low on the chassis, such as lower arm mounts, bulkheads, or simple plates that go under your battery or electronics.
- Move the battery. A quick and easy way to accomplish a weight redistribution is often to move the battery. It is one of the heaviest components in the car, and most cars come with multiple battery mounting options, so if you need just a little more steering, or a little more rear traction, you can try moving the battery before resorting to adding weights.
- Move the motor. Like the battery, the motor is very heavy, so moving it forward or back can have a significant impact on the car's handling.
- Change transmission layout. Some cars, mostly 1/10 scale off-road, have optional transmission housings that re-arrange the transmission gears to redistribute weight either to the front or the rear.
Adding weight
Aren't we supposed to be making our cars lighter? Why would we want to ADD weight? There are a few reasons:
- Making minimum weight: Cars these days are designed to be super light, so sometimes weight needs to be added just go get up to the minimum weight for your class, and if you have to add weight, you'll want to place it strategically so you can use it to improve handling.
- Improve handling: Some drivers also find that their car needs to be a little heavier to handle properly. This is often true on rough tracks where the extra weight improves stability.
- Improve balance: sometimes once you finish building and laying out your car you may find that it's too heavy on one side, so you can use weights to even out the weight to ensure even handling when turning left or right (or to maximize left-turning ability in the case of dirt-oval.)
General guidelines for weight changes:
Front-Back Weight Distribution
Shift weight forward
- More steering
- Less rear traction
Shift weight rearward
- Less steering
- Improved rear traction
Left-Right Weight Distribution
For most racing types, you'll want roughly equal weight distribution from left to right, so your car handles the same way when turning left or right. In some types of on-road racing, you may want to have a little more weight on one side if there are a lot of high-speed turns going in one direction.
In dirt oval racing, drivers distribute weight to the left side of the car, so it has maximum traction, as weight balance will tend to shift more weight to the right side. See our Dirt Oval setup guides for more.
Vertical Weight Distribution
In all types of racing, it's best to keep the weight (and therefore center of gravity) as low as possible. This reduces the amount the chassis will roll. If you want more chassis roll to create more grip, use other settings like the anti-roll bar or roll center.