Rushing up in the rearview mirror, a 2018 Dodge Challenger SRT Hellcat looks like it’s fixing to inhale your license plate through its wide-mouth hood scoop. Inspired by jet aircraft and race cars, Detroit has been slapping hood scoops on cars going back to the 1950s, including faux air breathers on the Packard Caribbean and Ford Thunderbird. When the 1964 Pontiac GTO debuted with a pair of dummy scoops, the feature became essential to muscle-car identity, although many remained purely ornamental.
Today, the big scoop on the Hellcat (and dual snorkels on the 2019) helps satisfy the supercharged Hemi’s voracious appetite for air, according to Mark Trostle, a head exterior designer for performance vehicles at Fiat Chrysler. He explains that the various Challenger hood scoop designs, along with the driver’s side “air catcher” inner headlight, are functional, either ventilating the engine bay or directing air to the intake. Dodge offers a nonspecific performance claim for the scoops that supply the intake, and Trostle says: “The more air you can feed into the engine, the more fuel you can use, meaning more horsepower.”
Of course, looks are part of the deal, too, and Trostle acknowledges the scoops are critical to the Challenger’s unabashedly retro image. “The hood and air scoop options respect the brand’s design heritage,” he says.
You won’t find scoops on new Camaros or Mustangs, though. Even their top engines inhale through underhood intakes. What’s more, science and history suggest that any potential performance benefits from hood scoops would likely come only at high speeds. So what gives?
“There’s a basic concept of getting cooler, fresher air forced into the carburetor. With a regular air cleaner, the engine is breathing a lot of hotter air,” says Martyn Schorr, cofounder of Baldwin-Motion, the famous New York–based muscle car performance shop. In the 1960s and early ’70s, Schorr was also the editor of Hi-Performance Cars magazine, known for its bluntly honest muscle car tests.
“On the street, for the kind of driving that even enthusiasts do, you’re never going fast enough for a long enough period of time to boost engine performance by bringing air in,” Schorr says. “On the drag strip, there may be a small difference.”
Seeking a touch of authenticity and maybe a small performance boost, Pontiac offered an accessory kit to open the 1965 GTO’s scoop. In late ’66, the factory Ram Air engine option combined an open hood scoop with internal tweaks. Other brands followed suit, but did “ramming” air to the intake really lift power?
Given the many individual factors contributing to track performance, along with any factory engine upgrades packaged with a forced-air system, that difference would have been difficult to pinpoint. What’s more, some scoops, especially those with low-profile designs, might not have worked as advertised. As a car travels, a boundary layer of slow-moving air forms near the hood’s surface, potentially mitigating any “ram” effect. In an era before wind tunnel testing and advanced computer simulation honed the art of automotive aerodynamics, designing taller scoops or moving their openings closer to the hood’s front edge was thought to compensate. Such gimmicks abounded.
“Shaker” hood scoops on Mustangs, ’Cudas, and Challengers were attached directly to the air cleaner assembly and rose up through a hole in the hood, shaking along with the engine. The optional “air grabber” hood for the 1970–72 Plymouth Road Runner and 1971–72 Dodge Charger used a driver-activated switch to raise and lower a hidden air scoop festooned with cartoon shark teeth.
“The extra weight of the ‘air grabber’ was not made up by any power increase,” says Schorr, “but we all thought it was cool.”
The rear-facing cowl induction option for the 1970–72 Chevelle SS wasn’t a “scoop” at all. Under heavy throttle, a flap at the rear of the domed hood snapped open to draw outside air. The idea was based on a principle applied in NASCAR that race car intakes pulled air through a duct connected to the cowl vent, taking advantage of the high-pressure area at the windshield’s base.
“On superspeedways at 150-plus mph, that worked,” says Schorr. He agrees that if hood scoops didn’t boost muscle car street performance, they at least added “visual” horsepower at stoplights and drive-ins.
“Ram Air or fresh air induction was a race-car-driven product that caught on as a marketing tool,” he says. “It was done mostly for show, and it probably helped sell cars.” No matter what hood scoops did or did not do, Schorr’s conclusion is universal: The cars that wear them look bad-ass.