Types of Springs
There are three types of springs that have been used during the evolution of suspension systems. They are coil springs, leaf springs, and torsion bar.
A coil spring is a continuous spiral wire that is coiled to achieve its progressive streng
Coil Springs
A coil spring is constructed from round bar stock wire that is wound or coiled either by a hot or cold procedure. Cold wound springs are formed by an ambient temperature winding method: A spring winding machine extrudes the wire in a spiral action and then is cut to length. The spring is then heat tempered in a furnace, shot-peened, end-ground, preset for fatigue resistance, phosphate treated, and finally powdercoated for corrosive protection. The thickness of the round bar stock and the amount of coils will determine its strength and rigidity of the coil spring.
Most coil springs are located between the front upper and lower control arms. The weight o
The coil winding is another important portion of the overall performance of the spring. The distance between coils will determine the spring rate. A progressive coil spring will have a shorter distance and tighter wind at the beginning of the spring. This is known as the transition portion that controls the static load, then, as the load increases into the active load and progressively becomes greater, the spring compresses and it becomes stiffer.
Referring to the spring load, we are talking about the amount of weight that will compress the spring to a specific height, which is translated into pounds. Spring rate is the amount of weight applied to the spring to compress it 1 inch, which is expressed in inch-pounds. When figuring these principals, we must remember the spring rate will not change during the spring's compression, but the spring load will change. Many times, we see cut coils from a spring as a method of lowering a truck's ride height, but cutting the coils will also affect the ride quality and coil action, increasing the spring frequency, in turn, causing the action to be choppy and bone-jarring.
The progressive action of a coil spring becomes more prevalent as it is compressed. By cutting one coil, the spring will eliminate its less progressive action or a smooth transition, creating quicker spring. This characteristic is demonstrated when we see a lowered vehicle traveling down the road. As it rolls across the highway, its suspension strips, making it oscillate to a choppy, bouncy ride, giving the driver and passengers blurred vision.