In the early 1980s, automobile manufacturers began to ditch the round, paper air filter elements typically used on carbureted engines in favor of flat filters funneling air to fuel-injected engines. Often, factory air boxes reduce power. The air inlet passages provide the engine with enough air for stock output but are not performance-oriented.
*note- Please check local laws before modifying your vehicle. Vehicle modifications may void manufacturers’ warranties and may be illegal for use on roads and highways depending on where you live. Many modifications can cause failed smog tests.
Aftermarket Solution for Inefficient Stock Air Filters
A simple solution for many choked-up fuel-injected vehicles is to replace the factory air filter and box with an aftermarket piece called a cold air intake.
A rigid pipe routes air to the air inlet at the manifold from an open area near the radiator air inlet. Most cold air inlet systems feature an exposed conical filter. Air filters can be bare paper, cellular foam, or oil-bathed and are intended to draw more air from cooler places than the factory air filter.
How Cold Air Intakes Work
In theory, a cold air intake can add horsepower and improve gas mileage. The added performance is a result of a colder, denser charge of air. The free-flowing inlet pipe allows less turbulent air that is moving faster and contains more oxygen than stock systems. Well-built systems can increase both horsepower and torque and can improve fuel mileage as well. A cold air intake usually makes an engine louder because the larger volume of air is less restricted.
Things to Be Aware of Before Installing a Cold Air Intake
With most aftermarket car parts, you get what you pay for, and cold air intakes are the same. Dozens of online sellers offer really nice looking kits for cheap, and they claim some eye-popping power numbers, too. The reality is that most of these types of kits are inferior to the stock system, and may even cause idle issues, stalling, surging, and check engine light illumination.
Cold air intakes can increase the risk of water flooding an engine. High-performance filters can allow water to be sucked into the engine. This can result in a condition called hydro-locking. Hydro-locking is caused when water enters a cylinder. Unlike air, water does not compress. Hydro-locking can literally cause the engine to stop in mid-rotation, destroying itself in the process.
How To Spot A Good Cold Air Intake System
Several highly popular companies sell aftermarket cold air intake systems that are better than stock filters, but they are not cheap. A good first step is to research the filters for the particular vehicle that have been popular with owners. Try to find enthusiasts online for advice on the particular make and model of the vehicle.
Look for intake pipes that are as straight as possible. Some vehicles have issues with cold air intake pipes that have a 90-degree angle. These types of intake kits can make the air “roll” and confuse the Mass Air Flow Sensor.
A cold air intake is practically useless without a really good air filter. Cheap intake systems often include a paper filter element that is more restrictive than stock.
Air Filters for Cold Air Intake
Many companies sell performance air filters with claims of massive horsepower and torque gains. Most of this is marketing. A good system with a high-quality air filter will give most cars a 1-8 horsepower gain and about 1.5 miles per gallon extra under normal driving.
An inferior air filter makes the whole thing worthless. Spend the money on a good filter. Oil-bathed filters like those sold by K&N and AIRAID are exceptional in dusty, dry places. In severely filthy places, open-cell foam can help prevent clogging an oil-bathed filter.
The Easiest Upgrade
The average car owner can install a cold air intake on almost any vehicle in a matter of minutes using common hand tools. Removing the stock airbox is the most difficult part. Consult a repair manual that includes information on how to properly remove the air box without damaging it should you need to reuse it at a later time. Do not throw your stock system away.
Generally, cold air intakes will attach to the air inlet of the mass airflow sensor with a band-type hose clamp. A bracket typically fastens the other end to a solid part of the vehicle and directs the inlet toward a source of fresh air. The filter attaches with a band-type clamp to the inlet. Installation is complete.
Start the car and let it idle for a few minutes to ensure no check engine light comes on. If one does get a dash light, the airflow might be too high, or the air/fuel mixture may have exceeded specifications.
A good vehicle workshop manual will give instructions to do-it-yourself mechanics for correcting issues caused by high-flow filters that confuse vehicle computers. This situation is pretty rare when using one of the higher-end products because the companies have extensively tested the setups for proper performance. Generally, a good system will come from a company that has a helpful customer service line.
The engine is likely to produce more noise with a cold air intake system. A good cold air intake will make the engine sound more powerful. If for nothing else, a cold air intake can be worth the sound. If the noise is too much, consider using a high-quality sound barrier under the hood.
It is important to pay close attention to the emissions laws in your area. Many localities will not test or will automatically fail vehicles with aftermarket cold air intake systems. I hope you saved your stock equipment. Some states ban most aftermarket parts that don’t carry a certification.
The First Performance Step Any Driver Should Make
High-end systems can cost several hundred dollars U.S. It is possible to spend even more than that, too. A full custom cold air intake may run into the thousands. Performance air filters alone can cost $150 or more. Drivers must use a special oil to periodically clean oil-bathed air filters. Oil-bathed filters last longer than paper filters because drivers can clean and reuse oil-bathed filters indefinitely.
Buy the best quality system you can afford. A good cold air intake is the first step to really opening the performance possibilities of an engine. No modifications to the exhaust, timing, or other engine controls matter unless the engine can get more air.