What's The Difference Between A Cold Air Intake And A Short Ram Intake?

A cold air intake (CAI) and short ram intake (SRI) are both common aftermarket mods that replace the stock, restrictive air box, tubing, and air filter in a bid to add horsepower, sharpen throttle response, provide a more aggressive intake note, and possibly open the door to other mods that could make your ride go quicker. Cold air intakes and short ram intakes may look the same, but the tubing length, the type of air filter (usually dry or oiled varieties), the type of intake assembly (open or sealed compartment), and filter location set them apart.

Cold air intakes are designed to draw cooler air into the engine. To do that, a proper cold air intake should be placed as far away from the engine or other heat sources under the hood, which should typically be behind the front bumper, ahead of the wheel well, or any other spot that's not prone to heat soak. With that in mind, a CAI kit will typically come with longer tubes, more accessories, and in some cases, an enclosed filter box, in some cases. All of this also means they tend to cost more than short ram intakes, depending on the brand.

A short ram intake, on the other hand, consists of shorter tubing and a more basic, cost-effective setup, making it ideal for tighter budgets and vehicles with tight engine bays. While the shorter tube increases the airflow and offers a more direct path into the throttle body, a short ram intake sits exposed in the engine bay, which limits its ability to draw cooler air and deliver big power gains.

Yes, they can — but it all boils down to the product design. MotorTrend installed a short ram intake into an Infiniti G37 in 2010 and found out that the engine produced nearly 15 fewer horsepower with the mod versus with a factory air intake. It's one of a few cases where a mod could make your car slower instead of making it go quicker. But when done right, both cold air intakes and short ram intakes could produce horsepower gains, performance improvements, and could even make your car's engine sound better.

Jason Fenske of the Engineering Explained YouTube channel installed a short ram intake and cold air intake into a 1999 Acura Integra GS, tested the car, and compiled the data to determine whether the mods produced better results than a stock air box. As it turns out, the SRI managed to squeeze gains in low RPM and high RPM acceleration, with the only downside being in the midrange (3,000 to 4,000 rpm), where the car pulled roughly 3% worse compared to when equipped with the stock intake. 

Meanwhile, the CAI enabled the same engine to pull harder above 3,000 rpm, with a 4.64% increase between 4,000 and 5,000 rpm and a 3% bump when the rev needle hit 5,000 to 6,000 rpm. It's not all rainbows and sunshine, since the cold air intake made the car feel slower between 2,000 and 3,000 rpm.

Choosing between a cold air and a short ram intake boils down to the type of car you're driving, the intended application, and budget constraints. A cold air intake could potentially unleash more performance, especially when combined with other mods such as headers, less-restrictive mufflers, and an engine tune. However, CAI kits are more expensive and more laborious to install. And due to the filter's location, it could also suck water into the engine, causing it to hydrolock when exposed to water, heavy rain, or flooding.

Short ram intakes are cheaper, simpler, and easier to install. The horsepower and performance gains are generally not as noticeable as with a CAI, but SRIs are known for improving the throttle response while making your engine sound sportier as you mash the go pedal. Moreover, SRIs have fewer parts and can fit into tight spaces under the hood.

Overall, both a cold air or a short ram intake can yield significant improvements to engine sound, acceleration, and efficiency. Plus, they look utterly cool under the hood, and that alone may be enough reason for some to ditch the factory intake.