The presence of air suspension in a car provides smoother and easier control compared to shock absorbers, but in order install air suspension yourself you need to know how the depreciation system in a car works and how it works. You also need to have basic car repair skills.
What is air suspension?
Air suspension is a shock absorption system with the ability to automatically adjust ride height without using physical force. It has a number of properties, due to which it is installed not only on trucks and trailers, but also, more recently, on cars.
These properties include:
- Ability to control ride height. This function allows you to improve ride quality in any road conditions for its class, without changing the springs to stiffer and shorter ones or longer and softer ones. The air suspension can be adjusted for any of these options.
- Smoothing out body vibrations on rough roads. Spring shock absorbers are more sensitive to uneven road surfaces, which in turn requires more careful driving on damaged roads. The air suspension compensates for these vibrations, thereby reducing vehicle vibration.
- Excellent handling. Again, it is worth noting the fact that with different springs, different controllability. Stiffer springs give good handling on paved roads, but poor handling on rough roads. On soft springs it’s the opposite. The air suspension compensates for these differences by simply adjusting the pressure.
- Preventing subsidence under heavy load. The air suspension makes it possible to adjust the stiffness and height at which the ride quality is constant, regardless of the amount of cargo or passengers in the car.
Disadvantages of air suspension
Despite the many advantages, it has several significant disadvantages that may affect the installation decision.
Firstly, they are much more expensive than conventional shock absorbers, since the initial costs include the purchase of air bags, a compressor that will inflate them, an air receiver that regulates low ground clearance without a compressor, as well as pneumatic lines, sensors and a control unit. As a result, the sum of the components turns out to be too expensive and not practical.
The second factor is the almost complete lack of maintainability. This means that if any part of the system fails, it will only need to be replaced, which entails additional costs.
Another important factor is poor resistance to frost and road agents, because of which the service life of the air suspension is significantly reduced. If in case of frost, it will be enough to pour a little alcohol or a composition used in pneumotomosis into the pillow, then only branded and high-quality pneumatic pillows have protection against reagents.
DIY air suspension installation
If you still decide to install air suspension, and do it yourself, then you will need to purchase the following components:
- A compressor that will pump air into the air bag;
- receiver, adjusts the clearance height without the participation of a compressor;
- air bags, which, in fact, act as shock absorbers;
- lines that combine all components into a single pneumatic system;
- sensors that allow you to control the tilt of the body and its position, pressure in the system;
- the suspension control unit automatically controls the entire installation and processes the signal coming from the sensors;
- fastening parts.
It is advisable to order a turner in advance for fastenings. To avoid unreliability of the design, it is advisable not to touch the factory mounting grooves that are already in the car, but to adjust the installation to them. In the future, this will make it possible, if necessary, to replace them back with springs without much difficulty.
To install the suspension, you need to put the car on jacks, then remove the wheels and springs.
Further actions depend on the type of installation: you can install a combined suspension, where the cushions are installed directly into the spring or a separate air cushion, which is structurally more complicated. In general, the installation consists of the following steps:
- removal of racks;
- preparing a site for installing fasteners;
- installation of pillows with valves in mountings;
- racks with installed air bags are secured in place;
- at the next stage, the main air supply system, sensors, control unit, compressor and receiver are installed.
It is worth mentioning separately the backbone system. If you plan to install air shock absorbers on both axles, then it is advisable to use a four-circuit suspension instead of a dual-circuit one. It includes four valves, while controlling each of them separately. This will allow you to more flexibly regulate the roll of the car, since each airbag will maintain a given pressure. The compressor and receiver are usually installed in the luggage compartment.
After installing and connecting the system to the compressor and receiver, it is necessary to display the control panel with sensor readings and suspension adjustment buttons.
The last step is to calibrate the pneumatic system by pumping a small amount of air into the system and checking the clearance and pressure when the vehicle is fully loaded. We also immediately diagnose possible leaks by hearing or using a soap solution. It is important to ensure that all the airbags are inflated evenly and the ground clearance is the same in both the front and rear of the car. It will also be necessary to re-adjust the camber.
Air suspension cost
The average cost of a complete set of air suspension parts is approximately 30,000 - 40,000 rubles. The most expensive part is the air struts with a cushion and cost around 20,000 rubles. for all. The price of a compressor ranges from 4,000 to 5,000 rubles. Solenoid valves – 500 rub. for one. The rest of the cost consists of a pressure gauge, hoses, wires and relays.
Based on the above, it is advisable to install air suspension only on foreign cars or in warmer climates. Installation, for example, on a VAZ is not cost-effective. If you purchase cheaper components, they will quickly fail. It can justify itself only if the air bags are made of frost-resistant rubber and are not exposed to chemicals, but these are quite expensive.
We bring to your attention another project for installing air suspension. The object of this project was the Ford Focus car.
Air suspension diagram
The air suspension is built according to a 4-circuit scheme, which allows you to control each air spring separately. Air supply/bleeding is carried out using solenoid valves. For the 4-circuit scheme, 8 pieces were needed, 2 pieces for each air spring.
Manufacturing of front air struts
To make air struts, we needed: a shock absorber strut, a support bearing, an upper strut support, an air spring, a flexible hose. For the air strut, the universal air spring Aero Sport, specially designed for MacPherson struts, was selected.
Additionally, turning parts were needed: a piece of pipe with an internal diameter equal to the diameter of the rack, upper and lower air spring mountings. The upper mount has a recess machined for the support bearing.
From the shock absorber strut, either with a hacksaw or carefully with a grinder, cut off the area for the spring.
Cut a ring from a piece of pipe. The height of this ring is chosen so that the air spring in a compressed state corresponds to the shock absorber in a compressed state.
We put on the ring, the lower mount of the air spring and weld it to the shock absorber strut.
We screw on the air spring, put on the bump stop (cut from a standard bump stop) and fasten the upper support of the air spring with countersunk bolts.
In the end, we got this pneumatic strut.
Installing front air struts
Installing air struts is practically no different from installing a conventional spring strut. To remove the spring shock absorber strut, unscrew 3 nuts from the upper strut support, one nut from the stabilizer bar and one bolt from the steering knuckle. Next, use zip ties to compress the spring and remove the strut from the fist.
We install the air spring in the reverse order, in this case it is necessary to position the hose leading to the air spring so that it does not touch or rub against the wheel.
Installing air bags on the rear suspension
For the rear suspension, there was plenty to choose from - for the Ford rear suspension, the appropriate sizes were Firestone 267c, Contitech 2500, SS-5 and RE-5, Air House 2 air springs. From all this variety, the choice was made in favor of inexpensive Contitech 2500 air springs
To remove the spring, use zip ties, after first removing the wheel and hanging the rear part.
To install the air spring, an upper support, a lower support and a disk for attaching the air spring to the lower arm were made.
The upper support is attached to the subframe with the same bolt that attaches the subframe to the body.
The lower support is installed inside the lever. From below, the air spring is bolted to the lower arm through a disk (which acts as a washer).
Air suspension layout
The main part of the air suspension elements is located in the trunk - this is the compressor, receiver, valves, pressure sensors.
For the Berkut R20 compressor, a shelf was made of 12 mm thick plywood in the left wing.
And a false floor was made for the valves. In addition to the valves, a spare tire, tools and a warning triangle were hidden there.
Covers are cut from sheets of plywood, coated with epoxy resin to protect them from moisture and covered with carpet. The receiver is located on the cover above the valves. The receiver had to be placed on blocks so that the excess pressure relief valve did not rest on the floor and it was possible to drain the condensate.
After assembling the entire system and covering it with carpet, the trunk began to look like this.
Digital air suspension pressure gauge
It was also decided to make a pressure gauge for the air suspension with our own hands. And although there are ready-made pressure gauges, for example, from Dakota Digital, I wanted to make my own for two main reasons: displaying pressure in bars and in the future making a fully automatic system with several programmable height levels.
The heart of the pressure gauge is the ATtiny26 microcontroller from Atmel, which includes an ADC with 11 inputs, of which 4 are used. It would also be possible to add a 5th sensor to the receiver, as in pressure gauges from Dakota Digital, but there is no great need for this. For the ADC of the microcontroller, an external reference voltage source is used on the TL431 chip, because the internal one turned out to be not very stable. Pressure sensors are powered by a voltage of 5 volts and have an output voltage ranging from 0.5 to 4.5 volts depending on the pressure. The information is displayed on a 2-line LCD display WH1602B from Winstar.
The pressure gauge is assembled on a breadboard and installed inside the car.
Air suspension price
The table below shows the list and cost (as of August 2011) of the parts required to install air suspension on a Ford Focus.
| № | Name | Qty | Price, rub |
| 1 |
Air suspension for a car is a suspension with which body height can be adjusted relative to the road, change the ground clearance for off-road travel.
What is air suspension?
Air suspension is used for trucks and various trailers. This suspension is also used on business class cars. It can be the basis of existing similar pendants.
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The main purpose of this device is ensuring higher road safety and comfort when moving. Some business class cars are equipped with pneumatic elements at the base of the adaptive suspension.
Air suspensions can be divided into three main types. This single-circuit, double-circuit and quadruple-circuit suspensions. Air suspension is often included in a ready-made vehicle package, and can also be installed independently. If you install the suspension yourself, you will have the ability to manually adjust the body height. What is the difference between all three types:
1. Single-circuit suspension is designed for one axis car (rear or front). Single-circuit suspension is often installed on trucks, where the emphasis is on adjusting the rear axle of the vehicle, depending on the load on the body.
2. Double-circuit air suspension can be installed on two axles or on one. This allows adjustment of two axes. But if a dual-circuit suspension is installed on only one axle, then each wheel can be adjusted independently.
3. Four-circuit air suspension is a complex system. In this mode All four wheels can be adjusted, a support system is provided. This pneumatic system is controlled using an electronic unit. The support pressure is regulated with the assistance of special sensors.
The basis of the air suspension design consists of a control unit, special sensors, a compressor for air supply, a receiver, pneumatic elements for each wheel and a control unit. When the suspension is operating automatically, body height is adjustable depending on speed, inclination etc. The operation of automatic and manual adjustment is somewhat different. But in general, the principle and purpose have the same meaning.
On what cars does it come from the factory?
It’s interesting to know that one of the first cars to be equipped with air suspension was Citroen DS in 1955. And imagine, in the very first days, this car model received a huge number of applications, a third of which were made literally within the first hour.
The serial production of the Citroen DS was the first to include air suspension. Today, the production of cars of this brand with this configuration also continues, as well as cars such as Toyota, Mercedes, etc. It is better to use air suspension together with the standard suspension. It will, as it were, take on part of the load, working as an auxiliary element.
To be able to adjust the height of the body relative to the road strip, you can install air suspension and use it together with the standard suspension. Vehicles that are designed to transport various loads, with large bodies and medium-sized trailers, are produced with an already built-in pneumatic system. For example, such as Mercedes, Renault Master, etc. Also various models of dump trucks, large-sized trucks for transporting large loads. In these types of vehicles, a pneumatic system is mandatory. It facilitates the movement of the car and makes driving easier and more comfortable.
On which machines can I install it myself?
How to make air suspension yourself and what car models can you install it on? In practice, manufacturing is not particularly difficult. Contrary to the popular belief that such an installation is unreliable, this process is quite effective and feasible.
You can design and install yourself air suspension for VAZ car. There are some important points to consider. The most difficult moment in the manufacture of suspension for a VAZ is replacing shock absorbers with air springs. It is better to use the original housing of the racks for support. It is necessary to take into account the features of a specific VAZ model and the type of pneumatic cylinders used.
To design an air suspension for a VAZ car, you will need a set of certain parts and mechanisms. No worries. There are no difficulties in this process.
What is needed for this:
1. Compressor.
2. Set of 4 air bags. When selecting pillows, specific models can be used specifically for VAZ, and there can also be others suitable from other car models.
3. Receiver for air injection. It should be cylindrical for a VAZ sedan. For hatchbacks, the receiver is shaped like a spare wheel.
4. You will need 4 pcs. solenoid valves.
5. Connecting tubes.
6. Two pressure gauges.
Directly during the manufacturing process, you may need to purchase other related parts, wires, fasteners, etc. Approximate the cost of all elements in general will be from 800 to 1200 dollars. This depends on the individual design parameters and car model.
Advantages and disadvantages
Like any device, air suspension also has advantages and disadvantages. One of the advantages of having a pneumatic system is the absence of noise and smooth running of the car. A big plus is automatic clearance adjustment and the rigidity of the racks during movement. These qualities are inherent in factory installation systems. Regarding the four-circuit pneumatic system, manual installation is not used at all with this model with automatic control. Because it is a very complex and costly process to do on your own.
The disadvantage is low probability of successful repair. For example, pneumatic struts, when they fail, are already cannot be repaired. Only parts need to be replaced.
Cost of the kit and installation itself
If we talk about the cost of a pneumatic system, it varies. Depends on the type (single-circuit, double-circuit, four-circuit). And also the price depends on the manufacturer and supplier. In the price range in Ukraine the cost of pneumatic elements and kits can be from 4,000 to 25,000 UAH. Depends again on the type of model.
Installation cost depends on needs. On average, it can be from 2,500 to 10,000 UAH. It depends on your goals and individual wishes. Before you begin installation, you need to clearly and in detail explain to the technician all the nuances. Because every modification is an additional price. It is not always necessary to buy all the parts to assemble a kit. To do this, it is advisable to seek advice from a specialist in this field. After this already sum up the entire cost of installation and related items workflow.
Do-it-yourself air suspension was conceived a long time ago. The obstacles to its installation were financial difficulties and technical issues. But they were finally overcome.
The air suspension was installed with my own hands on a 1986 model, in the SL configuration.
Air suspension diagram
The air suspension on the car is built according to a four-circuit design with 8 valves, 2 valves per cushion - one valve for air supply, the second for return. The scheme will allow you to effectively control each air spring: lower the left side, raise the right side or vice versa, lower the front of the car and raise the rear, etc.
Fig.1 Moskvich-2140
Fig.2
Air suspension components
Unfortunately, they do not produce ready-made air suspension kits for domestic cars, so I assembled the air suspension with my own hands. Main components of air suspension - air springs from America. Having studied the range of produced airbags, taking measurements with a ruler so that the air pillows would fit in place of the springs and not rub against the lower arms, an order was made.
Also, solenoid valves were delivered from America. In addition to all of the above, we purchased: fittings, tees, nipples, etc., a compressor - from a car store, an oxygen hose - from the construction market.
For the front suspension, RE-5 air springs from the American company Slam Specialties were chosen. The outer diameter, depending on the load and pressure, is 130-139 mm. If the diameter was larger, the air bags rubbed against the sides of the lower arm. In addition, the RE-5 has built-in bump stops, so the car's standard bump stops are not needed. For the rear suspension, Dominator 2500 cushions were purchased.
Fig.3 PP
The electromagnetic type valves for the air suspension were controlled under a voltage of 12 volts. The valves have a flow area of 15 mm and this allows them to pass a huge amount of air through themselves, which will make it possible to very quickly pump and bleed air from the air bag. With these valves, the Mosvich will rise and fall in one second. The valves are connected with 0.5 inch plumbing threaded fittings.
Fig.4 Air suspension components
At the very beginning, the Berkut R17 compressor was used for the air suspension, but its performance was rather weak. Therefore, it was replaced by the Berkut R20 compressor, which is half the price of a similar design Viair 400P.
Fig.5 Berkut R20
The receiver for the air suspension is an air cylinder with a volume of 20 liters from the brake system of a KAMAZ vehicle. Some modifications were made: the U-shaped supports were welded, cut from a channel and painted. It has 5 holes - two at each end, and one for draining condensate.
Fig.6 Receiver
Installing air springs on the front axle
The main feature of the front axle of cars from the 60s to the 80s is the placement of shock absorbers inside the springs. Therefore, we had to place the shock absorber differently. We also had to move the brake lines. The PP fastenings were made using metal pads 3 mm thick. The upper one is attached to the cross beam and the lower one to the lower arm.
Fig.7 Front axle
Fig.8 Disassembled front suspension
Fig.9 Air bags
Fig. 10 Shock absorber on a new mount
Fig. 11 Front axle with air spring
Fig.12 Front air suspension
Installing air springs on the rear axle
A 5 mm thick corner was attached to the spar, which served as an upper support for the Dominator 2500 PP. The lower mount of the PP was made of several plates, which were secured between the springs and spacers. Spacers were needed so that in the lower position the body would lower onto the bump stops. The spring leaves were reduced to 3 pieces, and the stepladders were replaced from IZH-2715, since they are longer.
Fig.13 Details
Fig.14 Rear inflated PP
Fig.15 Rear air suspension
Air suspension control
The air suspension is controlled by yourself using a wired remote control G1910 from Gainta with 8 buttons. You can control either one airbag or separately the front or rear suspension and left or right side.
Fig.17 Remote control
Fig. 18 PD diagram
Paying tribute to fashion, air suspension becomes one of the attributes of the car. The direction of stance is becoming more and more developed, in which, without having air suspension, but let’s say a coil suspension, using the car in everyday use becomes more difficult and uncomfortable.
Air suspension is installed not only by connoisseurs of new tuning trends, it can also be very useful in the everyday life of the average driver.
Let's look at the main ones pros air suspension:
- Ability to adjust ground clearance (you can improve the cross-country ability of your car despite its lower class)
- Handling and roll (it is worth noting that despite the smooth ride, unlike springs, you can change the behavior of your car in a matter of seconds by adjusting the pressure)
- Drawdown when loaded (you can adjust the height of the car regardless of how loaded it is)
The advantages include many more factors that satisfy the needs of the car owner.
To the main cons can be attributed:
- Initial installation costs (since your car was not previously equipped with this function, you will need to spend money on purchasing all the units)
- The service life of air suspension due to external factors (frost, reagents, etc.) is significantly less than that of springs.
Main types air suspension:
- Dual-circuit - the ability to separately adjust the height of the front and rear of the car.
- Four-circuit - control of each air spring separately, while they are connected to each other via an electronic controller for dynamic and static control (this is a more expensive option).
As for air bags, they also exist. several types:
Air suspension components
Manufacturing of air struts
Before manufacturing air struts, it is necessary to decide on the choice of pillows, based on the weight of the vehicle and the diameter of the springs.
It is also necessary take into account the location of the spring(separately from the shock absorber, or the shock absorber in the springs).
For passenger car The most common and universal are Rubena air springs 114x2, 114x3, 130x2 and 130x3. 
For heavier vehicles, the Dunlop 152x2, 152x3 and Rubena 170x2, 170x3 models are suitable.
To make air struts, we will need machined flanges and brackets to mount the air spring. 
Welding flange (for strut, shock absorber).
For sale on the websites there are ready-made flanges for the diameter of the air spring, as well as ready-made semi-kits. Flanges to match the diameter of your pillow and stand can be ordered from the dealer. 
The bracket can be a blind type (photo No. 1) (if the shock absorber is located separately from the air cushion), or with a hole in the center (photo No. 2) for the shock absorber shank (if the shock absorber is located inside the air cushion).
photo No. 1
photo No. 2
The platform for the spring is cut off from the rack and a flange is welded to mount the cushion. 
A brace is placed on the cushion. 
And it is tightened to the welded flange on the rack using bolts. A bracket is also put on the cushion from the top and bolted to the flange; a rubber seal is put on the rod from the top.
Ready air strut.
If the rear shock absorbers are installed in springs, then the manufacturing process is similar.
If the rear shock absorber is separate from the spring, the manufacturing process becomes simpler. You won't have to weld anything anymore. 
Ready rear air spring (provided the shock absorber is located separately).
After air struts are manufactured, they must be checked for air leaks before installation. After checking, all that remains is to remove the old suspension and install a new one, stretch the hoses, wires, and connect the control unit. 
Installing an air suspension in specialized centers will cost quite a bit of money; ready-made air suspension kits or components, and installation by yourself will save you at least half of the budget. 
