Car suspension systems components include shock absorbers, springs, and linkages. They are responsible for smoothing out the ride and keeping your car in control. In this post, we’re going to be looking at the springs used in 3 major suspension systems: leaf spring suspension, coil spring suspension, and torsion suspension. And check out VW Polo lowering spring if you’re interested in modifying your VW Polo.
Suspension Springs
Suspension springs are the links between the wheels and the car body. They are used to compensate for uneven/irregular road surfaces to provide a comfortable ride. They also maintain the suspension system at a pre-determined height while helping the vehicle sustain extra weight without excessive sagging.
In the modern car, each of the aforementioned functions of springs is crucial for delivering comfort, accurate handling, and load-bearing capacity. These are three crucial concerns that customers look for when evaluating car suspension systems today. Let’s evaluate each type independently:
3 Main Spring Types Explained
1). Leaf Spring
The steel multi-leaf spring is one of the earliest and most popular spring designs in suspension systems’ history. It has innumerable benefits because it not only serves as a spring but also connects the axle to the chassis directly. Besides that, you can adjust the widths, lengths, numbers, and thicknesses of the spring leaves to meet various load-bearing and ride-control needs.
Leaf springs tend to function as their own rebound dampener because of the friction created by the rubbing of the leaves. In rare circumstances, a typical steel spring can be swapped out for a plastic one that significantly decreases unsprung weight and withstands corrosion from factors like road salt.
When it comes to applications, some cars use a singular type of leaf spring called the “mono-leaf” spring. Others like performance road cars use transverse leaf springs to create a lightweight rear suspension system, even though such leaf springs are typically only used in truck applications with solid drive axles.
2). Torsion Springs
Such systems use a torsion bar; a long-spring steel element with a length of about four feet that is intended to twist as weight is applied to the suspension system. A torsion bar will only fit the side of the car for which it was designed because they are typically preloaded with a clockwise or counterclockwise twist built into them.
This kind of suspension system has been around for years, common in vehicles equipped with short-long-arm (SLA) suspension systems. One major benefit of this kind of suspension system is the compact and lightweight torsion bar.
Moreover, these torsion bars can be used to modify suspension height because the tension of the bar is regulated by a threaded screw adjustment. As if that’s not enough, the versatility of the design is further increased by the ability to attach torsion bars to either the upper or lower control arms.
3). Coil Spring
To understand how the coil spring works, it would beneficial to think of it as a long, thin torsion bar twisted into a coil shape. The coil spring works on the same principles as a torsion bar because the coiled wire twists throughout the spring’s compression/extension cycles.
A coil spring can be utilized in many different suspension designs because of how little space it takes up, such as:
- MacPherson strut
- Solid axle with trailing arms
- Independently sprung rear axle
- Any SLA suspension system employing a spring or coil-over shock absorber layout.
Most vehicles today however use the coil spring variation that is employed in the MacPherson strut design. In general, though, the features of a coil spring differ. They are determined by the number of coils, overall diameter, length, and wire gauge.
In some circumstances, a coil spring can be made to accommodate different load-bearing capacities that increase as it is compressed. Such variable-rate coil springs are frequently used in chassis arrangements that occasionally handle severe loads.
How Do Springs Work?
They work according to the principle of sprung-to-unsprung weight ratios to cushion a vehicle against road irregularities. That said, a vehicle with no springs represents 100% unsprung weight.
In this illustration, if the spring is placed between the axles and chassis, the ratio might be 90% for the weight of the chassis and 10% for the weight of the axles and wheels. As a car travels faster, the springs start to soften the blow of bumps and dips in the road.
Final Thoughts
Springs are the foundation of any suspension system. They reduce the impact of up and down movement on the chassis by absorbing any energy caused by irregularities. They are also primarily used to hold up the weight of the car and cargo, which makes them critical parts of any vehicle.
If you have any queries or would like to enquire more about springs or suspension systems, please reach out to us.
