Back in middle school science class, we learned that in order to make fire, you need three ingredients: fuel, ignition and air- or, more specifically, oxygen. You’ll also remember that cold air is denser than hot air, putting more oxygen in the same amount of volume. While the modern internal combustion engine does a fine job of delivering fuel and ignition, that cold air part becomes tricky as you try to route fresh air from outside through a hot engine compartment. In response, in the late 1960s/early 1970s a fantastic variety of air scoops, in every shape, size and composition appeared on muscle cars- NACA ducts, single and dual ram air intakes and cowl-induction hoods.
Engineers realized that, to be effective, a hood scoop must be either mounted high enough to clear the boundary layer (the slow-moving air that clings to the surface of a moving object) or, if it is a NACA “low-drag” duct, mounted below the surface and designed to draw the faster moving air outside of the boundary layer into the duct. Other scoops are located at the rear of the hood, near the vehicle's cowl, where the curvature of the windshield creates such a high-pressure zone, and may be placed so that their opening faces the windshield.
All of these hood scoops looked very cool and helped sell muscle cars. They were also effective at providing cooler denser air for their engines (The high operating temperatures in the engine compartment result in intake air that is 82°F or warmer than the ambient temperature, and consequently less dense), but not a “ram air” effect. “Ram-air,” typically, would only occur at very high speeds, making ram air primarily useful for racing and not street performance.
1969 Dodge Super Bee- 440 Six-Pack (fiberglass lift-off hood)
1969 Shelby Cobra (NACA hood scoop)
1969 Chevrolet Z-28 Camaro (Cowl induction)
1970 Chevelle SS 454 (Cowl induction)
Another approach taken was the shaker hood that was seen on such high performance cars such as the ‘Cuda, Challenger, Mustang Mach 1/Boss 302, Torino GT and Firebird Trans Am. This type of hood scoop is bolted on top of the carburetor and protrudes from a massive hole in the middle of the hood. (Note- A little known fact was that the MOPAR shaker was also known as the I.Q.E.C.A.G- the Incredible Quivering Exposed Cold Air Grabber).
1970 Challenger R/T Hemi (Shaker hood scoop)
1969 Mustang Mach 1 428 Cobra Jet (Shaker hood)
1970 Ford Torino SCJ 429 (shaker)
1970 Pontiac Trans-Am (Shaker hood)
One of the first street cars to feature a hood scoop was the 1963 Shelby Mustang. This was followed by the 1964 Chevrolet Corvette. Hood scoops became an integral design feature on almost every muscle car starting in the late 1960s. They reached their zenith in 1970, with an astounding and exciting array of scoops- from sleek (1971 Mach 1) to outrageous (1969 Rambler Scrambler). Unfortunately, when the muscle cars died off in the early 1970s, due to high gasoline prices, exorbitant insurance premiums and emission regulations, most hood scoops disappeared with them.
1963 Shelby Cobra
1964 Corvette Stingray
1969 Boss 429 Mustang
1971 MustangMach 1
1969 Rambler Scrambler
1970 Hurst Olds HO 455
But, luckily, we now we find ourselves in the middle of an exciting new muscle car era, where cars with 485 horsepower and 797 horsepower Hemi engines can be purchased from the factory with full warranties. For Dodge, this new revival started in 2005 when the Charger was resurrected. This was followed, three years later, by the production of the Challenger SRT. Both of these muscle cars were equipped with “functional” hood scoops to complement their aggressive designs. These hood scoops, although not directly connected to the air intake, effectively reduced engine bay temperatures by 20-30F degrees. Since 2008, Dodge has produced no less than 8 different hood scoops for the Challenger, including the heritage-inspired T/A and shaker hoods! Also, very popular, are the cold-air induction Demon, Hellcat and Redeye hood scoops.
2005 Charger SRT
2008 Challenger SRT
2010 Challenger T/A
2015 Challenger Shaker
2015 Challenger R/T
2015 Challenger Hellcat
2017 Challenger Scat Pack 392
2018 Challenger Demon
2019 Hellcat Redeye
We are truly in a new “golden age” of muscle cars!