Everyone would like to get a little more power out of their car. Keep this simple idea in mind: cold in and hot out, and you are on your way to achieving this goal, and you take the right steps to increase your horsepower.
First let's look at the idea of Cold In. Inside your engine fuel and oxygen combine and burn and produce power. Air contains the oxygen ingredient necessary for burning. The more oxygen the air can carry the more power you can derive. Since cold air is denser than hot air, you want to bring cold air into your engine and as much as you can supply. Restrictions in standard stock air intake paths result in less air getting into your engine. So you want to eliminate these restrictions in the air path.
Several aftermarket devices are available to help you do this. The simplest is a Ram Air Intake. This is a pipe and air filter that replaces your stock air intake parts. It speeds the air entering your engine, which means more air and oxygen and therefore more power. It may have a heat shield to reduce the engine heating up the air entering the air filter. Companies like, K&N, Injen, AEM, Fujitso, and Weapon R produce these devices.
Next is a Cold Air Intake. It extends the inlet pipe into typically the wheel well or behind the front bumper. Cooler air is found outside the engine compartment, so this device usually produces a little more power than a Short Ram Intake. It is a little more expensive and takes a little longer to install. All of the companies mentioned above also make Cold Air Intake products.
Last is a special filter that sits on a Short Ram like device. The filter has several tubes of different sizes inside and the company, Weapon R, claims the increased air flow because of this unique design, will give the horsepower of a Cold Air Intake with the size of a Short Ram Intake.
So for incoming air you want it to be as cold as possible and you also want as much air entering the engine as you can get. This will produce the maximum amount of horsepower. However, on the exhaust side you want the opposite.
The hotter the exhaust gas is, the faster it will exit the engine and the exhaust system into the outside air. This lets the engine run more efficiently. Any restrictions in the exhaust exit path, cause back pressure to develop and the engine must work harder to expel the burned gasses.
Some common techniques to achieve this are first, using mufflers that are designed to offer less restrictions than the stock mufflers found on cars. These are usually a little louder, but help you regain lost horsepower. Companies like Magnaflow, APEXi, Buddy Club, Skunk2 and Greedy make mufflers and the more complete cat-back systems to replace the stock pipes and mufflers.
Another step is to replace the stock exhaust manifold which captures the engine exhaust flow and directs it into pipes leading to the muffler. Again the stock system has restrictions in it. To improve the exhaust speed and keep some extra heat in it, you can add a Header System. This is series of low restriction pipes, cut to a particular length, that replace the stock exhaust manifold. Agency Power, DC Sports, Weapon R and Buddy Club make Header Systems.
A final step used by only a few people, is to wrap as much of the exhaust system in heat resistant materials as you can. This helps retain the heat in the exhaust pipes, which does two things. It speeds up the exhaust flow and keeps the air in the engine compartment cooler.
So we come back to the initial idea, cold in and hot out for maximum power.
