The torque arm is a suspension component that is mounted on a rear wheel drive car’s rear drive shaft. This arm allows the vehicle to accelerate in a straight line without rotating the rear axle. This torque arm also assists the vehicle’s brake by applying force to the braking system. The torque arm is used primarily in what the designers call a three-link suspension system.
The length and attachment point of the car’s torque arm are designed and constructed around the vehicle’s centerline. This is the point when the car’s suspension geometry intersects between front and rear. When mounting the torque arm so close to the center of the vehicle’s suspension, the greatest amount of rotational energy is transferred to acceleration energy.
Cyclists have been experimenting with vehicle suspension points for decades. By changing the mounting location at the smallest amount, the vehicle will respond to acceleration and braking much differently. In a racing-only suspension, the attachment points are adjustable to tune the suspension to change track conditions.
On a production vehicle, it is to be mounted, and the length of the suspension pieces constructed according to a compromise theory. The rector design is set up to achieve the best results over a given set of parameters. Considering all conditions in a street-driven vehicle, the suspension is designed to work well in a wide range of conditions.
This design practice is why some sports cars feel more like racing cars than any family sedan or pick-up trucks. The intended purpose of the car was investigated by the engineers and the suspension was designed accordingly. In designing the torque arm, engineers understand that street driven vehicles do not have to accelerate out like a drag-racing car and its design reflects real driving conditions.
Without a torque arm, the car’s suspension would bind as the rear axle tried to rotate around itself. The car would suffer from broken drive shaft and suspension pieces. Under the modest braking conditions, the rear axle would again attempt to rotate as the tires slowed rotation, and the suspension would again bind, causing the vehicle to slip out of control.
The torque arm is designed to provide adequate grip in wet weather as well as dry. Snow and mud are also taken into account so the car will work satisfactorily in all conditions. Race cars can be adjusted by pit crews during a race to improve the car’s driving characteristics. The street car must be adjusted on the design board and all performance features must be constructed at the time of manufacture.
- The torque arm of a racing car can be adjusted by pit crews during a race to improve the driving performance of the car.