A vehicle cannot place engine power onto the ground without several components. One of the most key components to a vehicle’s power transfer is its suspension system. A suspension system is responsible for keeping all of a vehicle’s wheels in contact with the surface that the vehicle is traveling on. Without adequate contact, a vehicle will not be able to maneuver properly.
A vehicle has many dynamic forces acting upon it as it moves across a surface. The vehicle’s suspension, which is comprised of several components, acts as a system to counteract the forces acting on the vehicle. There are three key principles to know in order to understand how the suspension system works in a vehicle.
1- Weight Transfer
As a vehicle accelerates, brakes and corners it experiences a dynamic force known as weight transfer. The amount of weight transfer that a vehicle experiences is determined by the vehicle’s center of gravity, the vehicle’s dimensions, the vehicle’s mass, and the acceleration of the vehicle. The three types of weight transfer are unsprung weight transfer, sprung weight transfer, and jacking forces. The types of weight transfer differ based on the components that support the transferred weight.
Dive and squat are the terms used to describe two of the most common types of weight transfer. Dive is the weight transfer that a vehicle experiences while a vehicle is under braking forces. Squat is the weight transfer that a vehicle experiences as it accelerates. Both of the terms attempt to depict the motion that a car makes under their respective forces.
The suspension systems of most vehicles are kept in equilibrium through the use of steel springs. Leaf springs are one of the oldest types of springs in history and are also one of the most commonly used spring setups on vehicles. Coil springs and torsion-bar suspensions are also commonly found on vehicles. All three of these spring geometries use steel springs.
Springs are governed by a force equation that relates the spring rate to the amount of travel in the spring. The spring rate is a measurement of a spring’s resistance to forces. Manufacturers obtain spring rates through tests performed within a spring testing machine.
Dampers are used to decrease the oscillations that occur within the unsettled suspension system of a vehicle. Dampers, also known as shock absorbers, are typically fluid-filled and utilize fluid properties in order to perform efficiently. Some manufacturers use gas, rubber bushings, or a combination of methods in order to create better dampers.
Dampers are mechanisms that are carefully engineered for their applications. In a case where a vehicle has insufficient damping, the vehicle will continue to bounce after it has traveled over a bump. A vehicle that has optimal damping will quickly return to a balanced state after traveling over a bump. The perfect damper settings depend on the comfort and performance that a manufacturer aims to achieve from a vehicle. These setting may also vary based on the conditions that a vehicle is expected to perform in.
There are many components that complete the suspension system of a vehicle. Springs and dampers are known as passive suspension components, but active components exist as well. The choice of which components to use within a vehicle’s suspension system depends on what the vehicle will be used for. The type of vehicle also plays a key role in deciding what components may work best.
Manufacturers often have to make sacrifices in order to optimize a vehicle for a specific application. As a result of these sacrifices, the suspension systems of vehicles provide varied levels of comfort. A vehicle that has a stiffer suspension system may not feel comfortable to ride in but may adhere to a road better. Contrary, a vehicle that has a softer suspension system will experience more body roll but will be more comfortable to its passengers.
No matter what factors go into creating the suspension system of a vehicle, as proved by numerous equations, the most important aspect is creating a suspension system that keeps a vehicle in equilibrium. Manufacturers aim to develop suspension systems that are both efficient and cost-effective.