Universal Hood Scoop Types and Installation Guide

Airflow plays a crucial role in a car's performance, and hood scoops are designed to optimize it. They direct cool air into the engine bay or air intake system. Hood scoops are commonly found on high-performance vehicles, muscle cars, and race builds, and come in various designs tailored to specific intakes, such as ram air or turbocharged systems.

Functions of Hood Scoops

Hood scoops serve multiple purposes, enhancing both performance and aesthetics:

Cooling: By channeling cool air directly to the engine, the hood scoop can reduce the atmospheric temperature under the hood. They may also work as vents, allowing hot air to escape the engine bay.
Air Intake: Functional scoops serve as inlets to your intake system. They help feed more cool, dense air into the engine, whether through a ram air setup or standard intakes. The result?
Aerodynamics: Controlling how the vehicle interacts with wind resistance can improve handling and acceleration.

Types of Hood Scoops

There are several styles of scoops, and choosing the right one depends on your car, your goals, and your budget.

Ram Air Scoops: These are designed to force air into the intake system at high speeds, effectively pressurizing the air before it reaches the engine.
Shaker Scoops: Mounted directly onto the engine, shaker scoops move with engine vibration and protrude through the hood. They’re popular on muscle cars for both aesthetic and performance reasons.
Cowl Induction Hood Scoops: These are wide, raised scoops located at the rear of the hood near the windshield. Cowl induction hood scoops are some of the most iconic, especially in terms of muscle cars.

Materials and Finishes

If your hood doesn’t already come with a scoop, you can install universal or fit-specific models made from plastic, fiberglass, or carbon fiber. These options vary in price, width, length, and finish (such as gloss black or matte black).

Installation Process

Installing a hood scoop correctly is crucial-especially if it’s functional. Here’s a step-by-step guide based on expert advice from professionals at Cars. Truck & Concepts, Fiberglass Trends, and Mahood's Auto Body:

Preparation

Measurements: If you’re cutting into your hood to create an opening, double-check all measurements. Consider the length, width, and position in relation to the intake or engine components. Locating the scoop means careful measuring to center it on the hood, but the fore and aft positions depend on taste and carb location. If the back of the scoop overhangs the rear of the hood, make sure it doesn't hit the windshield when it's open or the wipers when it's closed.
Material Selection: Look for scoops made from durable materials like plastic composites, fiberglass, or carbon fiber.
Sealing: To maximize performance, ensure the scoop seals properly with your intake system. This helps deliver consistent air flow and prevent leaks.
Aesthetics: If you’re painting your scoop, match it to your hood color or go for contrast with a black or carbon fiber look.
Shaping: Universal scoops may require shaping with sandpaper or a die grinder. The rear lip of the Harwood Z/28 scoop needed to be removed to fit the '82 El Camino used in this story. Mike Paradis also reshaped the rear radius of the scoop for a cleaner look.

Fiberglass Scoop Installation on a Steel Hood

This method involves bonding a fiberglass scoop to a steel hood for a seamless look.

Forming the Scoop: Once the scoop is close to the proper fit, use a heat gun to soften the 'glass and form it with a wooden block for a closer match to the curve of the hood. Heat the whole area to be formed and start shaping just as it starts to get pliable. Cool the scoop with water from a spray bottle while holding it in place.
Flange Trimming: Next, trim the scoop flange to about 1 to 11 inches wide.
Marking the Hood: 'Once the flange is cut, reposition the scoop and trace it with a grease pencil (a marker might bleed through the paint). Then remove the scoop and draw the shape of the hole you're going to cut in the hood, leaving 11 inches of metal for the scoop to bond to. Paradis warns that the hole will show from the underside, so make it a clean shape. Leave as much of the hood bracing as possible, especially at the rear.
Cutting the Hood: Cover the windshield to prevent pitting from sparks, then use a saber saw or cutoff wheel to cut the hole. Be careful not to cut anything under the hood if it is still installed on the car. Paradis trimmed only as deep as the sheetmetal so he could later decide what bracing to leave in place. If you do cut the braces out, tack-weld the edges back to the sheetmetal to keep the hood stiff.
Preparing the Bonding Surface: Once the hole is cut, use a 24- or 36-grit wheel to remove the paint and body filler and leave a coarse surface for the scoop to bond to. When using a disc sander, make sure that the rotation of the wheel is toward the opening (so the sparks fly away from you) or it could catch the edge and kick the sanding wheel back into you.
Prepping the Scoop: To prep the scoop, bevel the flange to a thin edge for a nice transition with the body filler from the scoop to the hood. Sand the underside of the flange to rough it up and to remove high spots. Now you're ready to position the scoop back on the hood. Use screws to locate the scoop and clamps to hold it firmly while the bonding agent dries. Thoroughly clean the scoop and hood with acetone because the adhesive will stick to the dust instead of the 'glass, causing the scoop to come off.
Applying Adhesive: The super-trick goo for bonding 'glass to steel is SMC Panel Adhesive #3 from Evercoat Plastic Works, available in quarts from most body-shop suppliers. After adding hardener, liberally apply the adhesive to the scoop flange.
Positioning and Clamping: Have a friend handy to quickly position the scoop before using the clamps and screws to hold it in place. Get it right, because it's never coming off. Don't bother wiping off the excess glue that squeezes out of the edges.
Sanding and Finishing: You can sand the adhesive with I v40-grit the next morning before finishing it with body filler. Paradis had a few more tips: First, ask the manufacturer how much prep the 'glass needs before you buy it; the Harwood unit was trick right out of the box. While the Harwood Z/28 cowl induction scoop is nearly perfect, some scoops aren't symmetrical. If that is the case, eyeball it until it looks best.

Fiberglass Scoop Installation on a Fiberglass Hood

This process involves bonding a fiberglass scoop to a fiberglass hood, often used on lightweight builds.

Initial Prep: The initial prep is the same as described above: Position the scoop on the hood, trace the inside and outside of the bonding flange as a guideline to rough up the gelcoat on the hood with sandpaper, bevel the edge of the scoop flange, then sand and clean the underside of the hoodscoop. Use screws to hold the scoop in place while it's bonding. This time we elected to cut the hole in the hood after the scoop was installed.
Applying Fiberglass Patch Kit: The installation kit for 'glass to 'glass is a fiberglass patch kit available from most hardware or marine stores. The kit should include 3-ounce mat material and a two-part polyester laminating resin. George Crabtree began by cutting the mat into strips as wide as the bonding area on the scoop and laying them into place.
Resin Application: Next, mix the resin and apply it to the mat liberally with a brush. Before the resin dries, install the hoodscoop in its final position and hold it in place with screws.
Finishing: Once the resin is dry, use a disc sander to grind the flange and excess mat, then finish the transition area with plastic body filler and sand it smooth. Crabtree uses a tongue depressor to make a nice radius in the body filler.

Bolt-On Scoop Installation

This is the simplest method, involving bolting the scoop onto the hood.

Positioning: If the hood has any ridges in it, simply clearance the scoop with a die grinder so you can position it on the hood.
Marking and Drilling: After drilling two locating holes, Mark Mahood affixed the scoop to the hood and traced around the inside edge of the attaching flange as a guideline to cut the hole in the hood. He left plenty of material at the rear of the hood so that the stock bracing could be left intact.
Securing the Scoop: Once the hole was cut, Wendall Pigman reattached the Unlimited scoop with the locating screws, and then he drilled the bolt holes from the underside.

Aesthetic Considerations

Unless you're revealing a 6-71 lung, a hole in the hood is a styling faux pas. Today's trend is to use a hoodscoop rather than leaving carbs flapping in the breeze. Fortunately, fiberglass manufacturers will bond a scoop and hood together for a reasonable fee. But if your hood isn't available in 'glass, if you want to keep a steel hood, or if you want to save some coin, you'll need to do it yourself.

Pricing

Hood scoops often vary in price as much as they do in style. Prices typically depend on the material, function, and brand.

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