336. The Yellow Banana
For the second season in a row, car manufacturers had tried to win their battles in the NASCAR rulebook instead of on the track. In 1965, Chrysler succeeded in its boycott and NASCAR caved on the Hemi. The next season, Ford tried the same trick with its OverHead Cam engine. Ford’s only problem was that they couldn’t produce one. Actually, NASCAR avoided the appearance of surrendering to the demands of the automakers. The engine, carburetion, wheelbase, brakes and weight rules were allegedly dictated by ACCUS, the Automobile Competition Committee of the US. The US version of FIA made stock car rules for NASCAR, USAC and SCCA, but NASCAR controlled the Committee. For 1967, both the OHC and the Hemi were allowed, but carburetor and weight penalties handicapped the big engines pretty well.
The main reason that speeds continued to climb was that Detroit, and Grand National mechanics, were learning about aerodynamics. In 1963, the “fastback” roof was introduced on the Ford Galaxie. The gently tapering roofline introduced less drag on the rear. For years, racers had used suspension tricks to lower the front end during a race. Most of these schemes were as simple as wedges stuffed in coil springs, but Smokey Yunick allegedly designed a hydraulic suspension that could be adjusted by the driver. Junior Johnson’s ride height adjustment was, supposedly, controlled by a cable.
'63 Galaxie Fastback
This creativity probably came to a head in 1966. The Pettys complained that the Fords were modifying body panels to redistribute weight and modify aerodynamics. A cursory examination of Petty’s Plymouth Satellite demonstrates that the Pettys were also master choppers of the era. The most blatant examples were Johnson’s “Yellow Banana,” which bore little resemblance to the original Ford, and Yunick’s “Chevelle,” a handbuilt, one of a kind, concept car.
NASCAR not only allowed, but encouraged some components that were judged not “standard,” but “high performance,” if the resulting car was more reliable, safer, or just plain fast. When the Hudson Hornet lowered the body on its postwar frame, engineers discovered a competitive advantage. Racecar constructors made advances in strengthening the frame, largely because of the tendency of vehicles to roll in a crash. Ralph Moody was experimenting with dropping the main frame rails altogether, using an aerodynamic floor pan integrated with the tubular frame. Very thin body panels were welded directly to the frame. While the Pettys complained this construction wasn’t strong enough in a wreck, the argument advanced was that it wasn’t production. It was, however, the forerunner of today’s NASCAR “stock cars.”
Johnson's Yellow Banana
For the 1967 season, the NASCAR rulebook doubled in volume, and inspections got more complicated. NASCAR backpedaled regarding production requirements, allowing the Hemi and the OHC, as well as performance chassis, suspension and drivetrain construction. To police the countless variations in makes and models, for the first time “templates,” rigid mechanical outlines of body contours were used to ensure (approximately) stock dimensions. The compact car class Javelin, Camaro, Dart, Mustang, etc) broke off to become the “Grand Touring Division.”
Although some of the “stock” was gone from NASCAR, the five hundred-piece production requirement for the Hemis and the OHCs led to the “muscle cars” of the late ‘60s and early ‘70s. Unlike the Corvette and Thunderbird, which were essentially lightweight sports cars, the muscle cars featured performance engines, transmissions, and suspensions, for straight line acceleration due to horsepower.
Although GM, publicly, still sat on the sidelines, Bill France must have found some satisfaction in Ford and Chrysler’s desire to “Win on Sunday.” Disappointed that Ford might be able to campaign the OHC, Chrysler threatened to ruin the 1967 season with another boycott, starting with the Atlanta race, right after April Fools Day.