There are many types of aftermarket air intake systems that range from simple and inexpensive to elaborate. In the scope of this article, we'll examine the different types of air intakes, what they do, and look at a few specific product examples of each. But in short, performance air intake setups increase airflow into your engine - boosting combustion and creating more horsepower and torque that you can actually feel. Their relatively low cost and easy installation (bolt-on in most cases) keeps them in popular demand by car enthusiasts that own everything from 1.5-liter turbo motors to big block V8 engines.
Packing more air into your engine allows more fuel to be burned without altering the optimum air-to-fuel mixture that produces peak power. Known as the stoichiometric air/fuel ratio, the actual ratio at which an engine operates most efficiently is 14.7 parts air to one part fuel. Keeping air and fuel at this ratio as supplies of both are increased means more forceful explosions in the pistons and more power to the wheels. If more fuel were pumped into an engine without a corresponding increase in air, you might actually experience a loss of power – along with the smell of extra fuel going out the exhaust pipe unburned.
The easiest way to improve airflow to your engine is to replace your stock air filter with a performance air filter. Such filters usually use cloth or synthetic material instead of paper to trap particulates. These materials may be more expensive, but the payoff comes as they allow air to pass through easier, without compromising filtration effectiveness that's critical to long engine life. Airflow can also be increased by using a larger air filter, but the size of replacement air filters is inherently limited by the amount of room inside the OEM factory air box.
An easy solution to this is to remove your vehicle's stock air intake tube and replace it with a freer-flowing air intake assembly that features a larger-diameter tube connected to an air filter that's conical in shape. Most factory air intake tubes are compromised by awkward bends and internal sound baffles created to reduce noise under the hood. While this contributes to a quieter-sounding engine, airflow and power are also suppressed.
Aftermarket air intake tubes rectify these issues with smoother interior surfaces, less restrictive bends, larger overall tube diameters, and air filters with filtering material that's not as restrictive to airflow. In the scope of this article, we'll discuss the basic types of performance-enhancing air intake assemblies: "Cold Air", "Ram Air", and "Short Ram" styles. We'll also reference examples of each in order to help you make a more informed purchase.
Cold Air Intake Systems
Cold air intake assemblies feature a longer tube with an air filter positioned on the front end. Because this filter is mounted further away from the engine block itself, it can draw air that's actually cooler in temperature. The filter is often positioned near the front corner of the vehicle or even directly behind a bumper or grille. Many cold air intakes feature heat shields that completely surround the air filter, or partially surround it and seal more completely against the hood when it's closed. The benefit of drawing in cooler air is that it's denser and packed with more oxygen - allowing more fuel to be burned for increased power. In fact, engineers estimate that every 10 degree F drop in intake air temperature increases power by one percent.
Because positioning an air filter behind a grille or below a bumper makes it vulnerable to water during extremely wet weather, many cold air systems are available with an extra "pre filter" (found in Product Options) that's designed to provide extra protection against splash-up from the road. When used in dusty conditions, it can also extend the filter cleaning or replacement interval by blocking much of the dirt from entering the main air filter.
In our section, you'll find a huge selection of cold air intakes for a variety of cars and trucks. For owners of Jeep Wranglers and classic 1984-2001 Cherokees, Jeep specialist Rugged Ridge offers the aluminum Air Intake Kit with heat shield. Owners of Subaru-powered vehicles (including the Scion FR-S) may appreciate the choices of powder coat finish on Perrin Performance's aluminum Cold Air Intake along with sound tuning designed to accentuate boxer engine exhaust notes.
And if you've got an older GM muscle car from 1967-72, AirAid's Performance Airbox allows you to build a custom airbox in the right or left corner of your engine compartment. It includes a conical filter and specially-shaped mounting bracket that serves as a heat shield/air dam. For Hondas, Acuras, and other imports, AEM's aluminum Dual Chamber Air Intake System features tubing that abruptly changes diameter halfway. This design creates multiple-frequency sound waves that charge the system with more air than conventional setups.
We've got cold air intakes where the air filter is completely sealed in its own box to keep dirt and hot air even more isolated. For pickups that see use in areas of heavy dust, Voltant's Cold Air Intake System features a patented style of air filter (licensed by Donaldson) with a fluted internal design that catches more dust without being restrictive to airflow. There's also aFe's plastic Magnum Force Stage 2 Si Cold Air Intake, K&N's aluminum 77 Series Hi-Flow Performance Air Intake Kit in larger sizes for 4x4s with big engines and more room under the hood, and Corsa's plastic Closed Box Air Intake System for performance cars.
If you prefer a cold air intake with a replacement air box that has a green-yellow-red needle gauge to tell you the condition of the air filter, take a look at the Injen plastic Evo Series Cold Air Rotomolded Induction System or the AEM Brute Force HD Diesel Air Intake System for diesel-powered vehicles. AEM also offers an aluminum Brute Force cold air intake without airbox that's geared toward larger gasoline engines found in 4x4s and late model fuel-injected muscle cars. aFe's plastic Momentum GT Cold Air Intake System features a clear window to view the filter, but eliminates the gauge for those seeking a lower overall price.
If you've got an older Honda dating back to 1988 and have swapped a more powerful Honda or Acura engine into it, AEM has created the aluminum Hybrid Intake System just for you. It's custom-designed so you don't need to cut up a system for a stock vehicle in order to fabricate one that will fit yours. In the Product Options page, you'll be asked which one of many possible engine codes you've swapped into your Honda. Then, you'll receive a custom-crafted intake system that fits like OEM equipment - with all the performance enhancements cold air intakes are known for.
And when it comes to high-tech, AEM's aluminum Electronically Tuned Air Intake System offers the unique distinction of having a built-in electronic module that adjusts your vehicle's mass airflow (MAF) sensor. This way, the MAF sensor will correctly read the greater amount of air flowing through the larger-diameter intake instead of becoming confused and triggering a check engine light on.
Short Ram Air Intakes
Like cold air assemblies, "short ram" air intake systems also replace the factory intake tube, air filter, and air filter box (sometimes) with larger-diameter tubing and freer-flowing filtration. However, they feature shorter air tubes that keep the filter closer to the engine. The air they draw in won't be as cool as cold air intakes, but they do offer the advantage of fitting in tighter spaces in cramped engine compartments.
For fans of Asian and American compact performance cars, we've got the Injen aluminum IS Series Intake System, Agency Power aluminum Short Ram Air Intake Kit, and the DC Sports aluminum Short Ram Intake System. And if you've got a turbo-engine Subaru, check out Perrin Performance's aluminum Short Ram Air Intake that's available in red or black textured powdercoat finish. Or if you've got a Honda or Toyota from the 1990s or later, take a look at HPS's Short Ram Air Intake.
For these vehicles as well as other makes and models, we've got the Weapon-R aluminum Secret Weapon Short Ram Air Intake System, Injen aluminum SP Series Short Ram Intake System, and the AEM aluminum Short Ram Air Intake System that's available for select 4x4 models.
Ram Air Intakes
Another method of channeling cooler air into the engine is the "ram air" intake design. In this setup, a longer tube scoops up air from high-pressure areas at the front of the vehicle. But unlike cold air intakes which have the air filter positioned at the front of the tube, ram air assemblies have air filters mounted in a traditional location back by the engine. Ram air intakes may be equipped with additional pre-filters at the front for protection against splash-up and dust from the road.
Examples we offer are the Weapon-R aluminum Dragon Intake which can be configured to a ram air setup with an optional flexible tubing section that lets you run it wherever you need to in order to reach behind the vehicle's grille, behind an air scoop in the front bumper, or other location. The Banks polyethylene Ram Air Intake System features an air filter that's completely encased in a protective housing that replaces your factory airbox. A window in the housing allows easy inspection of the air filter's condition.
Throttle Body Spacers
Finally, while not an air intake system, another way to improve engine airflow is with a throttle body spacer that installs between the throttle body and intake manifold. Once in place, interior baffles create turbulence as incoming air passes through the throttle body. As this turbulent air arrives inside engine cylinders, it serves to atomize the fuel charge more completely - improving combustion and increasing engine efficiency. We've got throttle body spacers from aFe, AIRAID, and Jet.
Custom Air Intake Systems
Everyone, regardless of vehicle, can benefit from an aftermarket air intake system. Even if you've got a hot rod, custom car, or a rare model that no one makes air intake components for, we've still got you covered. For example, AIRAID's universal U-Build It Airbox includes a performance air filter, an air intake tube you cut to fit, and all the necessary hardware and connectors to create a custom system that will fit any engine like a glove.
Since we offer too many air intake kits to mention every one in this article, we recommend looking through the Performance Air Intake section of our website when you have a block of time to enjoy comparing different offerings that are available. As you'll see in the picture above, it's possible to enter the year, make, and model of your vehicle in the beginning of your search so that our website automatically does the work of narrowing down which kits are offered for your ride.
We speak from personal experience when we say that a performance air intake system is one of the most cost effective and easy-to-install accessories you can bolt to your engine. The improvement in power, sound, and looks will blow you away. We can't tell you which performance air intake system will make you happiest, but we can say virtually all the feedback we receive from our customers after installation is positive. We feel strongly you'll be just as satisfied!