What is a Cold Air Intake?
Cold air intakes are a fairly inexpensive and a great "bang for your buck" modification. No, they won't add quite as much power as a turbo or supercharger, but they will help your engine in many ways. Think of a factory air intake system as like breathing through a straw, now go for a jog. A cold air intake lets the engine remove that "breathing straw" to allow it to finally breathe freely on its own. Cold air intakes relocate the air filter outside of the engine compartment. That way the air can be supplied into the engine for combustion at a cooler temperature, in turn, providing more dense air, which means more power for your engine. The cold air intake filters are usually relocated to the upper wheel well area or near a fender where there is more access to cool free flowing air.
Not only does a cold air intake reduce the air temperature, but it also increases airflow. Aftermarket intakes remove the need for a box surrounding the air filter and instead use large diameter intake tubes that are smoother, have less bends and are often wider than the original factory ones. Removing the air box and using smoother tubes gives the engine uninterrupted airflow.
Does a cold air intake really make a difference? The good news is that although claims of actual horsepower and even increased fuel efficiency may vary, cold air intakes will in fact help increase your car's power and performance.
By itself, you'll probably notice an increase in power when the throttle is fully open. Some manufacturers claim as much as a 5 to 25 horsepower increase for their system. But if you team up the cold air intake with other engine modifications, like a new exhaust, you will create a much more effective flowing system. So think of it as just one part of many to increase your engine's ability to breath and exhale, to increase its performance.
There are a few drawbacks to consider when installing a cold air intake though. If the air filter is too exposed and sucks up water, it'll go straight into your engine which can cause hydro lock. Adding a bypass valve will keep the engine safe from this event.
Short ram intakes (SRI) are another option over the manufactures intake system. Short ram intakes look to increase power by reducing the amount of restriction on the intake air. In many vehicles, the intake air passes through a resonator and silencer box to help reduce the induction noise. This restriction can limit airflow. A short ram eliminates the resonator and filter box, giving the air a short travel distance and hopefully increasing power. That said, it’s pulling air from the engine bay, thus the intake air will be warmer than by using a cold air intake.
Breakdown of Intake to RPM Performance
Stock: Best performance at low rpm, which is where your engine will spend most of its time if it’s a daily driver. If you don’t want increased induction noise, this option will offer the quietest ride. This is recommended for those who use their car as a daily driver, which is ideal for city driving.
Short Ram Intake: Adds some benefit over the stock system, but the intake remains in the engine bay therefor it is only able to access warm air. This also increases induction noise. Power seems to taper as the engine bay heats up. This is a budget-friendly option for cars which frequently visit the track, and also reduces the risk of pulling in water via the filter versus a CAI.
Cold Air Intake: For overall performance, cold air intakes are the best option when the engine is revved to higher rpm. Induction noise is increased. A downside is that the location of the filter could potentially hydro lock the engine by pulling in water, as it is often located close to the ground. Yet this can be avoided by adding a bypass valve. This is recommended for track or drag vehicles which keep the engine revs at higher rpm.