Cars aren’t just about huge power numbers, blistering acceleration, and high top speeds. Unless you have the proper suspension setup, you won’t get to experience any of the fun.
The importance of suspension cannot be overstated. It allows the vehicle to accelerate in the first place, nulling any acceleration squat, provides stability when cornering, and increases safety when braking by keeping brake dive to a minimum. This relates to keeping the vehicle at the correct height in relation to the road, the tyres firmly planted, and the wheels aligned all the while supporting the weight of the car and the occupants inside. Of course, there’s a comfort to think about too.
Different systems do a different job when soaking up road imperfections and some are more refined than others. The good news is that there’s no shortage of suspension types meant for different vehicles and driving that fit in differentiated price brackets.
A newer trend is air suspension. It’s what luxury car makers consider as standard or optional equipment since it allows the car literally to glide over the road. Many new tech inventions are poured into this suspension type to improve drivability, handling and comfort. It builds on all these aspects compared to other setups that are often limited to the divide between better handling or better comfort levels.
What Is Air Suspension?
This type of suspension replaces the vehicle’s stock springs with a set of airbags or bellows. These are filled with air and pressurised and lift or lower the vehicles to get the right height.
This can be done manually with input from the driver or automatically by a series of sensors and related tech that scans the road in front and adjusts the bellows accordingly. The same system allows for micro-adjustments, so drivers get better all-around versatility and make changes to the suspension possible even when driving at speed.
While the popularity of air lift suspension on the market is recent, the concept of cars riding on air has existed as long as cars themselves. In fact, military vehicles have used this system before it moved into the commercial sphere, with buses, lorries and larger trailers now featuring some air-adjustable suspension to handle the higher loads.
For cars, the ride height can be tailored to specific needs either slamming the vehicle lower to the ground and bettering handling and performance or lifting it up for increased comfort. Different parts all have a role here.
Parts in Air Suspension Systems
A typical air ride kit consists of said airbags or springs, modified shocks, compressors and air tanks, valves and solenoids, sensors and management systems connected by air lines, fittings and valves. All vehicles with traditional springs, including hatchbacks, estate wagons, sedans, pickups, SUVs and people movers can have these kits. And this can be a basic kit going only on the rear axle to help with higher weight loads in lorries, vans and pickup trucks or fully-decked out systems on both front and rear axles.
Air Bags
This is the part that does the literal heavy lifting. An airbag is a heavy-duty vulcanised spring able to carry heavy loads (in excess of one ton over each wheel) and filled to very high air pressures of up to 100 psi.
There are different types to choose from, some being able to be used with the stock shock absorbers or kits that include calibrated shocks for a more balanced and tuned performance.
Designs also differ. You’ll find double-convoluted airbags, resembling two tyres on top of each other and tapered or rolling sleeve airbags. The latter is more common in rear axle setups in vans and pickups and helps with excess weight at the back, and traction in the front. Double convoluted systems are found in cars and have shorter suspension travel and progressive spring rates.
Tanks, Compressors, Valves and Solenoids
Tanks store the air needed to inflate the airbags to the required pressure. Since the air inside them is pressurised, this can be done in just a few seconds.
They differ in size and can take quite a bit of space if you’re planning on mounting it in the boot. Valves can open and close to regulate the amount of air getting into the airbags or being released when lowering the vehicle. Solenoids take some of the guesswork out of the process, as they do this electronically and are lined at the outlet end of tanks.
Compressors are simple air pumps supplying tanks with air. Controlling the air pressure between tanks and compressors is done manually with a pressure switch, or the entire affair is settled with the digital management unit so you can focus on driving.
Air Management Systems
These are the brains of the whole unit. And you’ll be paying for the privilege if you want everything controlled automatically. The cheapest systems are driver-controlled by way of a pair of paddle valves installed in the dash.
Digital management systems can be divided into a few types. The simplest are those that adjust the air pressure and include predefined settings. A step up is pressure-based systems that automatically adjust the pressure in the air springs as you drive.
However, complete control is achieved with systems working with pressure and height sensors, so you can keep the vehicle at a specific height but change the pressure based on the level of cabin comfort or performance you want out of the car. Creature comforts like auto-lifting on startup and changing ride height with a few clicks on your phone are what make auto air suspension worth every penny.
The system is connected with bespoke airlines made of hardened plastics in cheaper kits or braided metal in more costly options, each terminating in the appropriate fitting to seal the system. The diameter of the airline can impact the speed of airflow, and how fast the whole air lift suspension system lifts or lowers the vehicle.
Benefits
Adding such a system to your vehicle certainly has its benefits. There’s increased ride comfort, as the pressurised air springs do a better job at absorbing potholes, cracks and uneven surfaces than what you have in stock.
This is well suited for a smoother ride on the poor-quality roads the UK is known for and is particularly handy in cars designed to go off-road. Here air suspension is miles ahead of anything else and features in top-spec Range Rovers, Defenders and Discoveries among other high-end cars.
An air suspension kit will also reduce the strain of related suspension parts, meaning less wear. And this has the roll-on effect of reducing vibrations and noise through the cabin, with the car gliding over any nasties on the road or off it.
Then there’s the level of adjustability. The vehicle can be lowered or lifted to the preferred height, and ride quality won’t be affected as the car is slammed to the lowest possible position or sitting much higher up. Air suspension trumps traditional coilovers in this respect. And it offers much better handling, meaning the car is more responsive when cornering, with a more taut feel through the steering wheel providing better vehicle control. Vehicles can remain level at all times and this enhances grip in the tyres and improves road holding.
In this respect, the systems help with better weight distribution, which is something derived from lorries. When set at the highest position, the car is well suited to overcoming different off-road obstacles, and systems that can individually lift the vehicle above each wheel will perform best. In short, the high level of adjustment and versatility suits different driving styles and settings without forgoing comfort.
Lastly, consider that lowering the vehicle at speed just a few millimetres produces less drag, thereby cutting down on fuel use. Kits may be costly, but they will completely transform your car. Better handling, improved vehicle dynamics, the ability to adjust the suspension to the peculiarities of the road, lower fuel economy and vastly improved levels of comfort are all worth it.
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