Why do you install an anti-spoiler on your car?

Why spoilers are installed on cars, how to choose or make them with your own hands

Almost every car owner devotes quite a lot of time to his vehicle. And we are talking not only about repairs, scheduled replacement of consumables and preventive measures. Also the motorist wants to give his car individuality, to make it more perfect, original and recognizable. And ideas are realized in different ways. For these purposes there is a range of solutions, among which often stand out the spoiler on the car. Once spoilers were the patrimony of only sports cars that competed on the tracks. But then they migrated to civilian cars, largely losing their original purpose. Previously it was an element of aerodynamics, directly affecting the behavior and characteristics of the car, but now the spoiler is more of a decoration, a decorative element for the vehicle. Much depends on the right choice and installation. If you choose the spoiler correctly, you can achieve noticeable changes in terms of safety, comfort and drivability of the car. But you should be careful, because mistakes in changing the aerodynamics of the car can lead to the opposite effect.

Why are they installed

Not everyone fully understands why spoilers are needed on the car. It depends directly on what kind of antifender will be used. If we talk strictly about real antifenders, rather than decorative overlays, such structures are able to perform several functions simultaneously.

1. The aerodynamic characteristics are improved and the vehicle speed increases. Due to the creation of more downforce at high speed the car is able to go faster without losing stability. The winglets can qualitatively change the aerodynamics of the body, making it more streamlined, and reduce the resistance of the oncoming air flows.
2. Another reason why we need spoilers is to increase the stability of the car when it is moving at a high speed. This is again achieved by the downforce. Air streams passing through the wings as if press the car to the ground, maintaining the necessary contact patch of wheels with the road. Figuratively speaking, the spoiler prevents the car from taking off, as the strong air currents passing under the car create a wing effect. This explains the other name of the spoiler, i.e. antifender.
3. The handling is improved. The actual reason why the car needs a spoiler at the back and sides. Installation of a rear and side antifender allows improving the quality of vehicle handling, the car becomes more obedient. Side antifenders create downforce, which makes braking more effective. The front winglets reduce front loading, while the rear spoiler creates a downforce effect. Altogether, this helps ensure good handling.
4. The swirling air currents are created. This is rather an additional bonus, because it prevents the active ingress of various debris and water on the windows.
5. Visual effect. Far from always the motorist wants to achieve some improvements in terms of functionality and performance. This is logical, since all these effects are manifested when driving at high speed. At low speeds, there is no need in antifenders. Therefore, the owners of civilian cars prefer to use the spoiler purely as a decorative element for the external tuning of their car.

Each motorist must decide for himself which specific spoiler he needs and for what purposes it will be used.

Characteristic disadvantages

Although antifenders have a number of objective advantages, you should not forget about the presence of the same objective disadvantages. They can be decisive in the final decision regarding the choice and installation of spoilers on the trunk lid, the front end and other elements of the vehicle. Let’s consider the main disadvantages that the motorist may face while using the antifender on his car.

• Additional problems during washing. Here, it is necessary to clean the elements of the antifender more carefully and carefully by hand. It is not always possible to direct a powerful stream of water on them at the car wash, as it will break or damage the construction. To a greater extent, this applies to decorative antifenders. Sports real aerodynamics elements are more resistant to mechanical damage. But it is still difficult to wash all components;
• Driving in reverse. If the antifender is massive and high, it will noticeably complicate the issue of driving in reverse gear. Visibility will be impaired, you will have to be more attentive and careful. As a solution to the problem you can install a rearview camera and parktronic with the image output to the screen inside the cabin;
• Vandals. In almost every city there are unscrupulous people who want, for one reason or another, to spoil someone else’s property. In this case, spoilers become an extremely vulnerable element of the car, because it is easy to break, and not always responds to such actions car alarms;
• The possibility of a sudden breakdown. This happens when the installation is carried out by dubious professionals, the installation is carried out by a crude method or banal use of unsuitable mounts. As a result, while driving the spoiler can suddenly break and fly off. It is a direct threat to the driver and other traffic participants;
• Corrosion. Installation of full-fledged antifenders involves drilling holes in the car’s body for the subsequent reliable fixation. It is very important to use qualitative fasteners and to treat the holes with anticorrosive compositions. Otherwise, the fixing place will become a hotbed for further active corrosion spreading with all the ensuing consequences;
• The opposite effect. Every car, every car model has certain aerodynamics and characteristics. Under them, spoilers should be selected individually, to some places to increase downforce or reduce lift capacity. For this reason, it is recommended to install antifenders in complete packages, where each element will have its place and perform the correct functions. Different homemade methods of installation and the wrong choice of designs lead to exactly the opposite effect.

Whether a car owner needs a spoiler or not is largely an individual question. No one prevents and prohibits installing a decorative wing, which will not affect the aerodynamics of the car, and serve purely as a decoration of the vehicle. But if we are talking about real antifenders, it is necessary to approach the question as responsibly and competently as possible. If you want to improve aerodynamics, you can by no means economize. Otherwise, it will result in additional costs and real problems. You should buy only verified, certified constructions, and trust the installation to professionals. As for the decorative elements, then you should also think about the expediency of such transformation of your car. Some cars are very beautiful by themselves, and the installation of antifender can only spoil the appearance of the car. There are many other ways to decorate and highlight the car, in addition to the installation of spoilers.

Recommendations for selection

There is no definite classification of spoilers designed for cars. Manufacturers offer all sorts of varieties of designs that allow you to install them on your vehicle. But in fact, you can distinguish the following types:

• Those designed to actually change the performance of the car. These are spoilers and antifenders, allowing to achieve better downforce, reduce swirls, reduce wind resistance and positively affect the aerodynamic parameters of the vehicle. Since such constructions are installed on sports and powerful cars, and their capabilities are shown only at speeds over 100 kilometers per hour, they are not necessary for most motorists. But for certain cases and high-speed cars a good spoiler will not hurt;
• Decorative. This is the most common type of spoilers for cars, which are used purely as an element of external tuning. They do not affect aerodynamics, and are used as a decoration. But with the right choice you can achieve a great effect, because the car looks more interesting, original and aggressive.

Having decided what kind of spoiler you need, you can go over the basic criteria for selection. Experts and experienced motorists give some advice and recommendations on this matter.

1. Material. The first thing you should pay attention to is the material from which the construction is made. Most of them are made on the basis of plastic and polymer compositions. Adequate price, decent features and ease of installation play in favor of plastic. If finances allow, it is worth looking at carbon fiber. The quality is higher, better strength and reliability. But also the price is appropriate. Optimal in terms of price to quality ratio is ABS plastic. But it is better to refuse fiberglass, as it is mainly used to make the cheapest spoilers.
2. Affordable budget. If you decide to invest in tuning, in the case of spoilers, it is not recommended to save much money. You do not have to buy the most expensive models for your inexpensive car. Look for the golden mean so that the purchase does not greatly hit the pocket, but the low price does not manifest itself in the form of low quality and short-lived design.
3. Conformity to the car. You can also classify spoilers according to whether they are universal, or designed for a particular model of a particular car brand. There are a number of cars that are in demand among fans of tuning. And especially for them to create a unique model spoilers and other aerodynamic elements. There are also universal models. They are in theory suitable for all cars, but in practice it is better to make sure they correspond to the size of the car and the possibility of installation on the body. Model models are usually more expensive, but their purchase is fully justified.
4. Color. Some people choose the spoiler by eye, not paying much attention to exactly what color the car itself is. Because of this, there is an unpleasant visual contrast, when the tone of antifender differs from the shade of the body. It is better to know in advance the exact color of your body, what you can look in service books or on sites of manufacturers, and also by VIN-code. Already on it will be more correct and easier to determine the color palette of the spoiler.
5. Method of attachment. There are two main options how you can install the aerodynamic element on the car. It is worth talking about this separately.

These are the main points, which is really important to pay attention to when choosing an element of aerodynamics for your vehicle. We cannot say that the spoiler is a mandatory and necessary element. Aerodynamics is thought over even at the design stage of the car model, the body is subjected to various tests. The spoiler only allows you to slightly change the behavior of the car at high speeds, as well as change the external perception of the car.

Installation nuances

Having decided on the design that suits you, it’s time for installation. As mentioned above, installation is divided into 2 main types:

If you want to apply a rigid mount, the installation procedure should be treated very carefully, as well as the choice itself. After all, such installation involves drilling the body. Making a mistake when choosing, as a result, the car will be left with holes, which are unlikely to please the motorist. To begin with, let’s analyze the peculiarities of the rigid bolted connection. Here the procedure looks approximately as follows:

• It is required to take a drill with a drill bit, sandpaper and a good anti-corrosion agent for metal;
• The spoiler itself is placed at the place of installation, make marks for the mounting holes. Do this carefully so as not to drill several times in different places;
• Make the holes. Sand them with emery cloth, and then treat them with an anti-corrosion agent. This step is very important, because untreated hole will be a hotbed for the development of corrosion;
• On the inside of the trunk lid is mounted bolt connection. Everything is tightened firmly.

This completes the procedure. Accuracy and precision is important, but there is nothing particularly difficult in the work. Now regarding how and what to glue the spoiler to your car, using the soft method of installation. Mounting glue, where the main mounting material is the glue, is relevant primarily for decorative spoilers that do not carry in themselves a practical load in the form of improved aerodynamic performance. Such installation looks approximately as follows:

• First you need to prepare the materials and tools. Here you will need degreaser, wipes and a person who is ready to help you. Mostly you need a helper to level the spoiler before gluing it;
• Some spoilers already come with double-sided adhesive tape, on which the element is mounted. Glue can be an alternative. But when dismantling it can severely damage the paint layer. Double sided tape is preferable in this regard;
• Try the spoiler on the place of future installation. Make appropriate marks to ensure that the construction stood perfectly flat;
• The surface should be carefully degreased and treated with dry wipes. It is strongly not recommended to glue on a dirty body;
• If there is no tape on the spoiler, you need to take a double-sided tape, one protective film removed and glued to the bottom of the spoiler, by which it will be placed on the body;
• Next, remove the second protective film, and already on the prepared surface is pressed firmly;
• Having pressed, wait a few minutes so that the adhesive can harden well.

That’s it, the work is complete. The main attention should be paid to the accuracy and evenness of the installation. Any deviation will adversely affect the appearance of the vehicle. It is better to accurately measure and mark everything beforehand than try to install the spoiler straight by eye. Do not take chances. Take a little more time, but do it accurately.

Homemade spoiler

Despite the availability of an impressive range of ready-made spoilers and the possibility to make a custom-made spoiler, many people still think about how you can make an original spoiler on your car with your own hands. In fact, such a design can be created from improvised means. There are many options and a guide for assembling spoilers. But it is not recommended without appropriate experience and professional equipment to try to make aerodynamic designs that can affect the behavior of the car. The production of such elements requires following strict rules and obligatory tests in wind tunnels. Therefore, when creating spoilers with their own hands, we are mainly talking about simple decorative structures. For their manufacture use:

• plaster;
• foam plastic;
• metal;
• installation foam.

This will be the basis for the production of homemade antifender or spoiler. But it will be necessary to take some additional materials and tools. The motorist in the process of work may need:

• fiberglass cloth;
• fasteners;
• welding machine;
• brushes;
• primer;
• paint;
• sandpaper;
• reinforcing mesh;
• spatulas;
• epoxy adhesive, etc.

The entire procedure is divided into several basic steps. It is important to follow the sequence, and carefully perform each process provided. It all looks approximately as follows.

1. The shape of the future spoiler is set. To do this, use foam, installation foam or plaster. The plaster can be molded and some existing spoilers can be copied. The foam is easy to work with, and the metal frame allows you to create a base, and later trim it.
2. When the base is created, it must be necessarily strengthened. For this purpose, glass fabric, reinforcing mesh and epoxy adhesive are used. It is better to apply these materials in several layers, so that the construction is as strong and resistant to mechanical influences as possible. Just glue the painted foam is not possible. Wind resistance will simply destroy it at the first acceleration.
3. After reinforcing, you need to treat the construction with putty. Choose high-quality compositions that can withstand the weather loads. That is, the putty must be resistant to temperature changes and precipitation.
4. Complete the fabrication process by painting. Don’t forget to use a primer before applying the paint to make it better. Choose the color carefully, unless you want to intentionally make the spoiler different from the main color of the body.
5. It remains only to install the homemade spoiler. As an attachment it is better to use double sided adhesive tape, or a special moisture-resistant adhesive. To use bolt connection is actual only if you use heavy metal frame. It definitely will not be able to hold on the glue. Then you have to drill holes, process with rust-preventive compound and tighten with bolts and nuts.

If you have the desire, every motorist can create your own spoiler. It is only necessary to choose good materials and competently use the tools. But think twice before making it yourself and in general install such a design on your car. Spoilers do not suit everyone, plus you need to be very careful in choosing the design element of aerodynamics, even purely decorative type. Many cars even without them look great. If you want to install a spoiler, it is better to use quality products from the leading manufacturers, designed specifically for your car. And the installation should be entrusted to professionals in this business. Then the result is certain you will not be disappointed, and you will not want to get rid of the spoiler in a week.

What is the purpose of a spoiler on a car?

Many cars, from sports cars to simple sedans have various aerodynamic elements on the back of the car. Any element that is installed on the trunk lid, rear door or on the edge of the roof, commonly used to be called a “spoiler”. In fact, there are two different devices that have a different device. Let’s understand why you need a spoiler on the car and what else is called a spoiler.

Spoiler and antifender

A spoiler is a part that changes the free flow of air. A rear spoiler is a body element that is installed on the back of the car (on the trunk lid, or roof). The spoiler has no gap with the body. If there is a gap, it is already an antifender. As the name suggests (spoiler – obstruction), the rear spoiler interferes with the flow of air, changes the fast, smooth flow coming from the roof. By obstructing the airflow, the spoiler changes it, reduces the speed of the airflow and creates pressure on the rear end, preventing it from lifting. This is one of the functions of the spoiler. Also, designed specifically for specific cars, spoilers can reduce the overall air resistance created by the car.

Left – antifender, right – spoiler

The antifender creates downforce at the rear of the car. The antifender is essentially an inverted airplane wing. The wings of an airplane generate the lift force that helps it take off. The antifender works the same way, but because it is an inverted wing, it generates downforce. Hence the name (wing for takeoff, antifender for downforce). The airplane wing and the antifender have different angles of attack. The antifender has a negative angle of attack. To put it simply, the air flow puts more pressure on the top of the antifender, and the airplane wing has more pressure on the bottom.

In English, where, in fact, the word “spoiler” came from, there is no name “antifender”. There, such an element of the body is called a “wing” (wing). It is also commonly known as all tuning elements, installed at the back of the car (and not only) spoiler. Although, the word “antifender” itself reveals the meaning of this device and does not give any confusion. The antifender is a wing on the contrary (inverted wing).

What is the difference between an antifender and a spoiler?

Broadly speaking, an antifender is also a spoiler, but with a special configuration and with a specialized function. The antifender, like all spoilers, interferes with and modifies the free flow of air. The only function of the antifender is to generate downforce.

The function of the spoiler can be different, depending on where the spoiler is mounted and what shape it is shaped into. One of the functions of a rear spoiler is to prevent the rear of the body from lifting. It accomplishes this function by creating a barrier to free flow. The air presses on the spoiler and the rear end is pressed down. The spoiler can also reshape the bodywork, improving aerodynamics.

On bodies where the roof ends and there is no smooth continuation further in the form of glass and trunk lid (on hatchbacks, minivans, etc.) turbulence is created. This increases the overall drag and brakes the car. A properly designed spoiler (see illustration) can reduce this effect, which will subsequently affect fuel consumption as well. But this can only be noticed during long, high-speed driving on the highway. At 120 km/h and above, 50% of the fuel is spent on overcoming air resistance. So, by reducing drag, it’s possible to achieve tangible fuel savings. Unlike the antifender, the spoiler does not require fine adjustment during installation.

It begs the question, why press the car to the road

At high speeds (over 120 km/h), the air blown under the car begins to lift it (starting from the rear), like a giant wing. Because of this, the steering is impaired, especially when cornering. So, if you try to turn the car at high speed, the car can fly off the road. The only way to reduce the car’s lift at speed is to increase its weight. The problem with increasing weight to improve traction is that it doesn’t help in corners, when you need the most traction. The extra weight has inertia to overcome in order to turn. Plus, because of the extra weight, fuel consumption increases. Thus, adding weight to the car for better traction is a failure.

The antifender is precisely the device that helps press the car against the road at high speeds.

Its advantage is obvious. Instead of a heavy, clumsy car, you can drive a lightweight car that is easy to control and the higher the speed, the more force it has on the road. But there’s a catch. Every time the antifender generates downforce, it also generates air resistance. The air resistance brakes the car. So, extra downforce is good, and too much downforce, generating a lot of drag, is bad. Very powerful sports cars that compete in Formula 1 have an indicator called the L/D-coefficient. Car designers try to increase this coefficient so that the car would stick to the road well enough and not slow down at the same time.

Examples of the application of antifenders by manufacturers of high-powered cars

For example, you can take Koenigsegg ccx. It is a car with the 4.8 liter engine that produces more than 750 horsepower. Weight of this car does not exceed 1 ton. This is not a bad car, but it has gained the reputation of being undriveable at high speeds. The lack of a rear spoiler, with its light weight, made this supercar unstable at speed and cornering at speed turned into a horror. After much criticism, the company released a new model with a spoiler already installed.

Here’s another example. When the first versions of the Audi TT were launched, there were a series of accidents due to lack of grip during cornering at speed, including in the wet. There was also an incident with a famous German racing driver who died in an Audi TT . After these incidents, a recall was issued for every Audi TT sold, and each was fitted with an antifender. Subsequent models of this car already had an electronically controlled antifender that extended when reaching high speed.

An example of rear stabilization with a spoiler was the Ford GT40, the LeMans winner. Initial testing at high speed showed the rear end to be unstable, wobbly. The higher the speed, the more badly this “wobble” could end. The problem was solved by installing a small spoiler on the back of the trunk.

Formula 1 race car at 300 km/h due to the antifender generates downforce equal to the weight of a small car. Too much downforce is not good either. For this reason, the Bugatti Veyron and the McLaren P1 have retractable antifenders. They extend when the supercars reach speeds of 120 km/h so as not to fly off the road and they slide back slightly when the car reaches speeds of 250 km/h so that the huge downforce doesn’t take out the rear suspension. In order to generate downforce, the antifender has to be tilted (angle of attack). The flow of speed coming off the roof towards the rear of the car will be blocked by the antifender which in turn generates downforce.

The vertical flat elements on the sides of the antifender prevent the air from “spreading” out on the sides and, in some cases, can increase the efficiency of the antifender by up to 30%.

If the antifender is not designed correctly, it can give excessive drag and still not “press” the car. Usually, spoiler and antifender manufacturers design their products for specific car models. Many are more concerned not about the steering stability and traction at high speeds, but the sporty look that these tuning elements create.

It is important that the antifender is installed at the correct angle.

Proper, professional installation of an antifender requires about 3 hours of testing and adjustment in a wind tunnel. An improperly installed antifender can harm the car’s aerodynamics and increase air resistance. Also, too much downforce from the rear of the car can be generated, which is also bad and will impair handling.

Front bumper liner (“lip”, “skirt”)

In addition to a spoiler or antifender, it is advisable to install a front bumper overlay. It reduces the gap between the bumper and the road, thereby reducing airflow under the car. It also reduces lift at high speeds.