What Are Air Suspension Systems and How Do They Work?

Air suspension systems have long been employed in the trucking industry, but they've only just made their way into the commercial sector. Suspension systems are used in motorcycles, all-terrain vehicles, custom vehicles, performance cars, and even regular commuter cars.

Due to various technological advancements, systems are no longer clumsy, sluggish, or inaccurate. Instead, they employ powerful electronics and rapid, precision-based technology to manage everything from ride height to bag pressure, resulting in a smooth, controlled ride.

It's about time, too, because the car's suspension system is frequently disregarded. Your car's suspension is crucial to how it drives in terms of comfort and safety. Shock absorbers and coil springs work together to absorb and direct road force, allowing wheel oscillation, jounce and rebound to be maintained.

However, every time you add or remove weight from a vehicle, accelerate or slow down, or turn left or right, the shock absorbers and springs are put to the test. Traditional factory shocks and springs are only designed and fitted to handle a specific set of scenarios.

Air suspension systems were pretty simple in the beginning. The coil springs were replaced with air bags. An outside compressor was used to inflate the bag to the right pressure or height through a valve on the bag. Changes in technology and usage introduced additional components to the system, as well as greater control. However, today's air suspension systems all share a common set of components that differ little from one manufacturer to the next. The key distinctions are in the controls and simplicity of installation.

The material used in air bags hasn't changed much over time. The bag is made of a rubber-polyurethane blend that provides structural integrity, airtightness, resistance to light abrasion from road debris and sand, and salt and chemical corrosion resistance.

The bags are available in three basic styles:

1. Double Convoluted Bag - This bag is designed like an hourglass and has two compartments. The design offers slightly more lateral flexibility than the others.

2. Tapered Sleeve - This air bag works the same as any other, but it's meant to fit into a smaller space and has a bit more ride height flexibility.

3. A Rolling Sleeve - This type of air bag that is designed for a specific use. The main differences between the two sleeves are ride height and spring control, as well as what works best for the vehicle and application.

An on-board compressor is currently standard on most air suspension systems. The compressor is an electric pump that feeds compressed air to the bags through compressed air lines. The compressor is usually located in the trunk or on the vehicle's frame. The majority of compressors include a built-in drier. The compressor draws outside air into the pump, compresses it, and transports it to the bags. Outside air is frequently damp, and moisture in a closed system may cause chaos. Before the air is delivered through the system, the drier utilises a desiccant to collect as much moisture as possible from the air.

Compressor systems with fewer components rely on the compressor to maintain, raise, or reduce pressure. An air tank is added to more modern systems to maintain pressure and offer a smooth transition between pressures. Compressors can be turned on manually or automatically, and they can be operated simply by the driver, automatically via an electronic system, or a combination of the two.

The suspension system is controlled by a set of valves that allow air to flow in and out.

Of course, an air suspension system is more than simply a basic bag. The components that make an air suspension system operate are listed below:

The compressed air is sent to the bags via lines that are identical to standard high-pressure air lines that run along the vehicle's frame. While most lines are made of rubber or polyurethane, they may be changed with bespoke steel lines, which have a cleaner appearance and are more durable.

These allow air to pass through to different portions of the system. Valves are essential in today's air suspension system for separating and regulating where and how air is channelled. Two-way air suspension systems were common in the early years of the industry. A connection connected each left and right air bag, and the air was shared. One air bag compressed its air and pushed it through the line to the second air bag, which was inflating, as the car turned. As a result, there was a lot of body roll, which contributed to the bad reputation that air suspension systems had. Systems now employ a set of valves to regulate this inclination and improve handling.

These are utilised to fill and vent each air bag in electronic-controlled systems. As the system reacts to changing conditions, each solenoid is instructed to open or close, affecting the volume of air in each bag. An electronic control module is used to manage electronic systems. The controlling software can be very basic, practically a digital replica of analogue on/off switches, or it can run more complex software that continuously monitors pressure and ride height. The modules collect data from a number of sources, including ride-height sensors, and turn on and off the compressor as needed. Most innovation has occurred on the electronic side of the system, and modifications will most likely occur in the future. The on-board components and communications of the vehicle are usually kept independent from these systems.

Set shock absorbers and coil springs are used in production vehicles and replacing them without affecting the car's ride or handling takes time, patience, and knowledge. And deciding on a suspension package may be difficult. A plethora of manufacturers and businesses supply a diverse variety of components in a befuddling mix of quantity and quality.

The fact that air suspension kits simply replace coil springs, and coil springs are part of a bigger suspension system, adds to the confusion. Given this, several firms provide whole suspension overhaul packages, in which everything from tie rods to control arms and shocks is replaced with high-end components that optimise the benefits of an air suspension system.

The most basic kits, on the other hand, often include air bags to replace a vehicle's coil springs, as well as a compressor and air lines. Most basic kits are two-way, which can cause a lot of body roll. Increasing the price of a product equals better components, which means greater control and variability, better components, and faster change.