SHOWnGOplus - Air Intake Systems

Ask any gearhead and they will tell you that one of the main keys to better engine performance is efficiency.

Most drivers tend to pay little attention to their automotive air intakes. It's understandable considering that people tend to think air is air, and anything that gets sufficient volume into the combustion chamber has to be good enough. As long as the gasoline is burning and the car goes where you want, there seems little reason to look for a different system, right?

In fact, the air intake system you choose can make a substantial difference in the life and performance of the car you drive. More than just a matter of meeting minimums, vehicle intake systems determine nearly everything about the way the car handles, accelerates and responds. Look closely at the top-rated cars on the market today and you will notice each of them carries a sophisticated intake system designed to meet the demands of higher performance.

First things first. Cars run not just on gasoline, but on a combination of gasoline and air. Boost the purity of either and you will quickly discover the equal role they play in governing your car's power output. Buying good gasoline is really only part of the larger picture, which is why those who know tend to prize better air intake systems over nearly every other replacement part when it comes to overhauling the feel of the vehicle.

How can you improve the air stream when you are limited by the exigencies of the atmosphere itself? Engineers attacked the problem years ago by focusing on filtering--removing the pollution, toxins and unwanted dust from the air to guarantee a cleaner burn. But there is a far subtler way to get better results, one which rarely rises above the radar for those of us who may not thumb through engineering texts for a living.

Now, you've hopefully taken a look at your stock airbox, which leaves a lot of room for improvement... Its big, its ugly, it harnesses the all mightiness of a paper air filter, and worst of all restricts you from hearing the sweet symphony produced by your factory equipped under hood sound system. Now that I've flattered your air box let me introduce to you to its angelic replacement.

Cold Rush
Dial back to high school chemistry for a moment and you may recall a basic fact about gases: they get denser as they get colder. The name of the game with air intake systems is maximizing oxygen in the combustion chamber, which is why there is so much emphasis placed on getting cooler air which carries more of this essential element than warmer air. So-called "cold air intakes" are designed to send cold air down the intake pipe to ensure your gasoline burns longer, brighter and more powerfully than it ever could on an anemic trickle of thin, heated air.

Good intake systems distinguish themselves with heat shielding, insulation and wide-diameter piping. Because pressure is the other great contributor to gas temperature, ensuring your jet stream enjoys a wide berth means the air can flow cool and fast without undue obstruction. Studies have shown truly dramatic effects from this dual emphasis on insulation and pressure--as much as a 10 percent boost in horsepower from a single replacement part.

Taking the step of removing your factory air intake system has an excellent bang for the buck ratio and as a result is often the first modification enthusiasts do to their new projects. Your new intake will allow colder air in larger amounts into your engine. For reference think of drinking soda with a stir straw vs. a regular straw, larger diameter equals more flow.

Smarter Ways
There is a noticeable difference between cars that merely reach the right speed and those that accelerate with a kick. Sometimes the simplest way to change the character of your automobile is to let it breathe deep for the first time in its lifetime. The best automotive air intakes not only improve the power profile of your fuel injection, they also keep the engine running cleaner for years to come.

Look around the Web for good prices on top names like AEM, Airaid, Iceman and others. Your engine works hard enough without having to contend with avoidable airflow problems that can quickly grow chronic or fatal. A good website will explain the different products and help you make an informed decision on some of the most competitive names in the industry.

The key to improving engine performance is the intake system. As an internal- combustion engine requires approximately 14.7 parts of air for each part of gasoline in the combustion chamber, getting enough quality air to the engine is essential. By quality air, we mean the big three: cool, clean, and compact. Here are some modifications you can do to give your heavy breathing engine all the quality air it needs.

The short-ram air intake provides enhanced fuel-air mix. Combined with a high-flow exhaust system and new computerized engine-control unit, the increased airflow helps boost horsepower. For even more power, you might consider a turbocharger and intercooler.

As any chemist knows, the colder that air is, the more dense it is, and denser air will provide more oxygen in any given volume (i.e. inside the engine cylinder), allowing your engine to burn more fuel and generate more power. A common rule of thumb is that decreasing the air intake temperature by 10 degrees F will increase horsepower and torque by 1%. The converse is also true. The problem with most stock engine intake systems is that they consist of just a box with a filter located somewhere in the engine bay where it fit. This box only draws in the hot air from under the car's hood and is probably not in the best place to draw cooler air. Furthermore, they tend to be quite restrictive, in an attempt to reduce underhood noise. Aftermarket "short ram" air intakes (that look like a cone on a pipe) are less restrictive and might provide a few more extra horsepower. However, they suffer from the same problem as stock systems in that they draw in the underhood air. Therefore, they work nicely after the car has been sitting overnight, but actually decrease in performance once the engine (and thus under-hood temperature) heats up. The better aftermarket systems try to locate their intake tip in an area under the engine bay that might have cooler air, such as near the bottom of the car or by the grille. This arrangement helps out by drawing slightly cooler air than that generally found under the hood and thus results in more of a power gain.

Depending on your budget there are 2 routes you can take; Short Ram Intake or Cold Air Intake.

A Short Ram Intake which is often referred to as a warm air intake, positions the filter still inside the engine bay, but at a point as far away as room allows.. Although this Intake setup still takes in hot air, a short ram intake has less restrictions and uses a higher flowing filter allowing air to flow much more freely into your engine. The result? Depending on what you buy, about a 4-8 peak hp gain depending on car and other modifications. It may not sound like much but take into account that you will be gaining power from 2000 rpm until redline, meaning your car will be quicker everywhere in the powerband.

A cold air intake (aka CAI) typically has a longer pipe and its filter is positioned low in the engine bay, close to the ground where it can suck in the rushing air that has not been heated by underhood operating temps. Cold air intakes provide significantly larger gains then a short ram, on some applications gains of up to 15 peak hp have been recorded although this wont be the case for every car out there.

When driving on dirt or other dusty roads, dust particles are drawn through the radiator and find their way into the engine if it is not filtered and cleaned. Dust and other foreign materials in the engine will cause excessive wear and operating problems. Air cleaners are made to separate dust and other particles in the incoming air before it enters the carburetor. Thousands of cubic feet of air are drawn from within the car hood and passed through the engine cylinders, so it is important that the air is clean. One of the easiest and cheapest modification is to replace your stock paper air filter element with a high performance one. Available from K&N and other companies for around $100, these performance filters are often made of cotton and provide less restrictive air flow while still filtering out particles in the air. Hot Rod magazine tested a K&N air filter and found a 5 bhp increase at the wheels on a 1996 Ford Mustang. Most of the horsepower gains is at higher RPMs when the engine really benefits from the less-restrictive air flow. While not a tremendous power gain, the filters' relatively low cost and ease of installation (about 5 minutes) more than make up for it. Plus, performance air filters last longer than cheap paper ones so you might actually come out ahead in the long run.

So how hard is it to install? This is a relatively easy do-it-yourself job--I rate it a 2. The vast majority are plug and play so don't worry about having to modify your engine bay any more then swapping intakes. There are a couple of things you should keep in mind when shopping for an air intake. If where you live gets a lot of rain and you plan on getting a cold air intake, consider also getting a bypass valve. The purpose of a bypass valve is simple, SAVE YOUR ENGINE! Referring back to Mrs. Johnson's physics class it's quite simple. Water is heavier then air, when you start to bring water into your intake system through your filter, air will take the path of least resistance and come in through your secondary system Aka your Bypass Valve. The bypass valve costs under 50 dollars and if it saves your motor just once it will have more then paid for itself.

Brand can make somewhat of a difference in performance. Each manufacturer claims to have the ultimate solution, but our dyno tests have consistently shown that Injen Air Intakes produce a bit more horsepower than AEM intakes, even though AEM is the most recognized name in performance intakes. Currently, AEM is the only company that offers a bypass valve. Injen offers a heat/splash shield, simply and effectively protecting the filter from water splashes. An important factor to consider when selecting an air intake is to make sure it meets your states smog control requirements.

THE POINT: Air intakes and filters make for a great first mod--they're easy to install, relatively cheap, and make a noticeable improvement in your engine's efficiency.