Air vents are pieces whose primary function is to improve the supply and circulation of air in a part of a vehicle, such as the engine bay or the passenger compartment. These vents may be installed on sports cars as standard or retrofitted for recreational use or racing. There are different types, whether they are mounted on the bonnet, roof or bumper, and they have different uses. We take a look at these accessories, which are very popular with customisation and motorsport enthusiasts!
Summary:
1. Air vents and scoops: definition
When it comes to car accessories designed to improve air flow, there are air vents and roof scoops. These relatively inexpensive, sporty-looking parts each have their own function:
Air vent
It is mainly used to optimise air circulation and allow better heat dissipation under the engine bonnet. This air vent or scoop is effective in hot weather or when the car is used intensively and for long periods. Mounted on the bonnet, it prevents the engine from overheating by guaranteeing good ventilation of the block and its peripherals. The reliability and lifespan of parts can be improved thanks to more efficient ventilation than stock.
Although it is not generally useful for increasing engine power, the bonnet vent can, if placed in a high-pressure area and connected to the intake system, increase the volume of air drawn in by the engine as the speed increases and thus provide a fresher, denser flow. This is known as dynamic intake, and the result is increased performance.
Roof scoop
Used in competition, roof scoops improve the ventilation of the passenger compartment for the comfort of the driver and co-driver. In fact, in motorsports such as rallying, where the presence of air conditioning would cause weight gain, loss of power and a larger footprint in the engine bay, the roof hatch is essential to bring fresh, dust-free air to the occupants.
The cabin temperature is lowered and the air in the cockpit is slightly pressurised to prevent dust from entering through the car’s other openings. The design of the roof scoop also ensures that the aerodynamics of the vehicle are not overly affected. In order to be used in rallying, this type of part must comply with current legislation (WRC, F2000, etc.).
2. The various types of air vents
Air vents differ in terms of shape, size, material… To help you see more clearly among all the available models, here are the main types of car air vents:
Standard bonnet vent
This is the most common air vent on the market. It is low in height, can be square or more streamlined and, depending on the direction of its fins, can draw air in to feed the engine bay or discharge it to remove heat more quickly. There are bonnet vents in FRP, carbon, ABS… They are most often universal air vents.
Raised bonnet air intake
This type of air vent can be found on standard or racing models. They are often used to supply fresh air to a top mount intercooler on turbocharged engines in order to optimise their cooling capacity. Often specific, these air scoops are integrated as standard into the bonnet of models such as the Subaru Impreza GT Turbo/WRX or Nissan Sunny GTI-R.
NACA bonnet duct
Originally developed for the aeronautical industry, the NACA (National Advisory Committee for Aeronautics) duct is a flush-fitting part to the bonnet which offers the advantage of generating low drag to minimise flow disturbance. While universal parts are available, they can also be fitted as standard to cars such as the Ferrari F40, Dodge Viper GTS and Nissan Skyline GT-R V-spec II.
Front or side air vent
These air vents are fixed on the front bumper or on the side of the vehicle and make it possible to supply fresh air to the intake system, an oil cooler, the passenger compartment or the brakes. These scoops are often associated with boa-type ducts in order to route the air flow to the part to be cooled. There are also air intakes that replace a headlight for increased performance on the circuit, for example.
Roof scoop
Riveted or welded, roof hatches can come in different designs and typically offer two configurations: open or closed. Some roof vents have a separate channel between left and right as well as diffusers to direct the airflow according to the needs of the driver and co-driver. A hose can be integrated to facilitate the evacuation of water in case of rain.
3. American air vents
Regarding air vents, American cars have been equipped throughout their history with original and innovative systems, especially muscle cars. Fitted with large carburettors, these large-displacement engines actually required a substantial air supply. This is how many of these now iconic cars have been equipped with air intakes of all kinds. Here is a selection of the most ingenious:
Air Grabber & Ramcharger
This system, mounted in particular on the Plymouth Road Runner or GTX under the name Air Grabber and as a Ramcharger on the Dodge Super Bee or R/T, was in the form of a shutter operable by the driver from the passenger compartment. It allowed more fresh air to enter the carburettors.
Ram Air
These intakes provide a kind of dynamic intake by bringing cooler air to the engine. The narrow shape of the inlet, which widens, also increases the pressure of the air sucked in. The Ford Mustang Mach 1, Pontiac GTO or Firebird Trans Am have notably benefited from this type of air intake.
Shaker Scoop
These intakes provide a kind of dynamic intake by bringing cooler air to the engine. The narrow shape of the inlet, which widens, also increases the pressure of the air sucked in. The Ford Mustang Mach 1, Pontiac GTO or Firebird Trans Am have notably benefited from this type of air intake.
Cowl Induction
Unlike a conventional air vent, the Cowl intake has its opening facing the windshield, allowing a large supply of pressurized fresh air without the risk of the engine sucking up stones and other debris. This system was installed in the Chevrolet Camaro Z/28 or Corvette Stingray, among others.
Photo sources: Autoworks Magazine / Speedhunters / DR