The suspension system of a car is very complex, with the parts inextricably connected to each other. Regardless of the shape and size of a car, only the 4 tires touch the ground and support the weight of the car, as well as the people and things it carries. Suppose a vehicle (front engine, front wheel drive) has a total weight of 1000 kg. When static, the front and rear tires on each side bear 300kg and 200kg respectively, while the weight load has some subtle changes when the car starts. Dynamic inertia will cause a transfer of weight to the car, regardless of whether it is accelerating, decelerating or cornering, resulting in rapid load growth on some individual tires. For example, if there is an emergency brake on the ground, the weight originally supported by the rear tires would be instantly transferred to the front tires. That is, the two previous tires, which in total only support 600 kg, will now support perhaps more than 800 kg. Also, if the car makes a sharp right turn while downgrading at high speed while the driver suddenly loses the accelerator, the weight load on the right rear tire would be zero because the car is now airborne. At this time, the weight load of the left front tire would reach 800kg, while the left rear tire and right front tire will bear 80kg and 120kg respectively. This severe imbalance phenomenon would allow the left front tire to slip due to the heavy load, thus losing steering ability. In this situation, if the driver presses the brake quickly, more weight would be transferred to the front. As a result, the left rear level does not have enough downward force due to the low weight load, so the friction force is not enough to deal with the left lateral force generated by the right turn, thus generating left traverse.
The above is a simplified example, but the basic principle is perhaps clear, and we can conclude that if we could reduce the weight transfer in a movement, the slip limit can be increased, resulting in a substantial improvement in overall management. And now I would like to present several methods of reducing weight transfer.
The first way is to reduce the weight of the car. Once the gross weight is lower, the transferred weight is reduced. That is, the weight load of the tires under the same conditions is less, so the limit will surely increase. Remember to reduce the useless things in the car, especially the trunk, because they will follow the dynamic inertia of the car to transfer, which will affect the stability.
The second way is to lower the center of gravity of the vehicle, because the lower the center of gravity, the less the car sways, which means less weight is transferred at the same time. The easiest way to lower a car’s center of gravity is to lower the height of the vehicle. But don’t casually cut the original springs to achieve your goal, as this could cause some side effects.
The third way is to strengthen the anti-heeling (roll stiffness) ability of a car, which requires strengthening the body and suspension system to suppress the roll amplitude of the car. The most common form of this type of modification is to install heavy-duty springs and shock absorbers, and to equip the car with front and rear tower bars, as well as anti-roll bars.