Hood vents, hood scoops, and bonnets are all part of the same vehicular structure. When they’re incorporated into the front (or rear) of a car, truck, SUV, or van, the cold air from the outside infuses the combustion mixture with oxygen to create powerful movement exchanges.
It is sometimes called an air dam in non-American markets.
The purpose of the hood vent is to allow for a direct air flow to the engine. That’s why it is necessary for it to be upraised.
You can also install decorative or closed vents that don’t serve this purpose, but still offer the aesthetic benefits of this design element.
Hood Vents Pros and Cons
Hood vents help an internal combustion engine to breathe. It takes air from the front bumper, routes it through tubing, and controls the temperatures inside the area. To be effective, the scoop must be in a high-pressure area on the hood, which is why some are placed near the cowl.
The scoop is usually most effective when it is higher than the boundary layer or serving as a NACA duct. When the vent only accesses the slow-moving air that clings to the surfaces of moving objects, there isn’t enough movement to create a desirable temperature change for acceleration and power.
When the hood vent is underneath, an effective design must funnel the air into the intake in direct, short paths to be effective. That’s why channels or tubes are used to create these benefits.
It is possible for the scoop to be part of the hood. The OEM or aftermarket product can also be part of the cleaner assembly or protrude through holes cut into the bonnet. Since the vent shakes while the engine is running, this style is often called a “shaker.”
◼️ What Is a NACA Duct for Cars?
A NACA duct, inlet, or scoop receives its name from the organization that originally invented the concept. It was initially developed in 1945 by the National Advisory Committee for Aeronautics.
When the vent design is correctly implemented, air can flow into an internal duct to cool the area without disturbance. It was originally considered a submerged inlet since it uses a shallow ramp and curved walls that get recessed to a streamline body.
The first applications of a NACA duct were for airplanes. The Ford Mustang used it for a few model years in the 1970s, along with Porsche, Ferrari, and Nissan over the years.
Most notably, the NACA ducts are on the 1973 Pontiac GTO.
What Are the Benefits of Hood Vents?
If you want to shift away from an airbox design or a standard fan in a sealed container, a hood vent is a reasonable alteration to consider. That’s why you’ll want to evaluate the different benefits that come with this investment. Does the cash equate to the performance you hope to achieve?
1. It increases the engine power.
Internal combustion vehicles need cold air collected through the hood vent to improve engine power and performance. The equipment requires oxygen since the fuel won’t burn without its presence. How much is needed, and the overall maximum output, depends on the ambient pressure and local static atmosphere.
Dry air that stays dense and cool tends to work better than when it is warmer and thinner. By installing channels with hood vents to deliver cold air to the engine, a vehicles performance can improve by at least 5% easily.
2. This tech can introduce compressed air.
Most air intake systems are dependent on local atmospheric conditions. If you compress this resource, it can be delivered in its enhanced state to deliver an improved performance. By supercharging the motion to force air into the engine, hood vents can act like a RAM scoop that delivers a massive intake that hits 10 times the power of a conventional design.
3. It creates intercooler exposure.
The temperature inside a car’s bonnet can increase quickly. This issue occurs because the engine works hard, continuously creating combustion to deliver power. There’s no place for the hot air to go, and turbos create an even bigger problem.
When you have hood vents available, the intercooler can function correctly. It keeps getting the cold air so that it reduces the air temps inside the bonnet. This set of circumstances works together to ensure the vehicle’s performance is up to standards.
4. Performance increases happen with hood vents.
Most of the hood vent benefits involve some sort of performance enhancement. Once installed, this part is known to boost the overall performance because cold air can flow into the engine compartment. Customizing the vents can deliver filtering benefits that prevent dirt, dust, and other problems from fouling the environment. You’ll see smoother operations that encourage more durability.
5. It makes the vehicle look fantastic.
You can choose to install hood vents for performance needs, but it is also an appealing aesthetic upgrade with this option. This part is responsible for several advantages, including adding to the overall resale value. If you don’t want to have a custom install performed, several companies provide aftermarket products that fit with your make and model. You don’t need to have a sports car to benefit from having more cold air flood the compartment.
What Are the Disadvantages of Hood Vents?
1. Rain can enter the engine compartment.
Although it isn’t a bad thing for the engine area to get wet (it happens with the spray from a rain-soaked highway all the time), you do need to prevent the water from entering the engine bay. In most circumstances, the moisture that reaches the area evaporates before touching the hot metal because of the heat in the area. Some manufacturers have set up “umbrellas” to let in the air without the moisture reaching it to prevent this disadvantage.
2. Dust can still enter the engine bay.
Even though modern hood vents use filtration to prevent dust and debris from entering the engine compartment, the design cannot stop everything. You can also pick up material from underneath, and even a little brake dust can sometimes filter through there to cause a few problems. That means you’ll need to spend more time cleaning the area outside of your regular maintenance routine to ensure things stay in working order.
3. Installation can be a problem for some cars.
Since hood vents can be an aftermarket modification, it isn’t always easy to finish the work on some vehicles. If the engine sits in an unusual spot, the mod might not even be useful. That’s why it helps to review all the potential specs before starting this project. Since the setup needs to happen in specific ways, some items might not even work unless extensive changes happen to the vehicle’s structure.
4. You need to make sure they are in the correct place.
It isn’t helpful to throw hood vents into any single location. Every make and model is a little different, which means you must think about placement and what it looks like for your overall needs. That’s why it is usually better to look at your vehicle for data instead of relying on the information from an aftermarket generic hood design.
Does the Hood Vent Need to Be on the Top of the Hood?
If you don’t like the idea of a hood vent standing tall on your vehicle, here is some good news! It doesn’t need to be installed there unless that’s the only place where a hotspot exists. Most vehicles can perform better whenever there is a new spot that lets hot air escape.
The goal is to allow the engine to work more efficiently in those circumstances instead of receiving a physically cooling mechanism. That lets you prevent overheating.
If you use side vents on most vehicles, you’ll end up with a lower temperature and cumulative benefits for other parts.
The disadvantage of installing hood vents is that you can damage the paint on your vehicle with an improper placement. If you create homemade ports on the side, you can weaken the strength of the panel or risk water coming in when washing the vehicle.
The best solution in this circumstance is to keep the vent position away from any fuse boxes, batteries, or other electronics. Louvres work better than vents in some instances.
You also have the option to wrap your intake tube with header wrap or insulated foil. Depending on how hot you’re running, the change could be as much as 50 degrees.
A Final Thought About Hood Vents
As much as it would be nice to experiment with different hood vent designs, you don’t have that luxury on a budget. What you need is a straightforward methodology that helps you achieve the goal of a cooler engine compartment without causing your vehicle to look like trash.
That’s why I highly recommend investing in an infrared temperature reader. This tool can help you pick out the different hot zones around your engine so that you can be strategic about where to place the hood vents.
It also helps to study how the air moves around the engine compartment to find ways to improve the intake.
When I need to check on this information, I love using the Fluke 62 Max infrared thermometer.
It has a 954 degree range (in Fahrenheit) so that you know you’re getting an accurate reading. It displays the minimum and maximum temps it picks up while giving you the range between what it detects. The item is certified IP54 for protection against splashing liquid and dust, while the lightweight clip lets you keep it right on your belt loop or tool carrier. The accuracy is within a degree.
What I like the most about the Fluke 62 Max infrared thermometer is that it has a 10:1 distance-to-spot ratio with its laser sighting. You know the exact place where you’re taking temps with this item.
Once you’ve found the hot spots, you can start thinking about the vent style and structure to incorporate.
You also have the option to keep things the same after evaluating the hood vents pros and cons that apply to your situation.
