Steve Magnante's 1001 Corvette Facts - Steve Magnante

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In these days of exotic hydro-formed frame rails, forged-aluminum suspension control arms, carbon-ceramic brake rotors, and plastic-based leaf springs, it’s shocking to learn that Chevrolet relied on simple metal shims to revise the Corvette’s front-suspension geometry in 1956. Positioned between the front control arms and their mounting points on the front frame rails, these simple stamped-steel shims added much-needed caster for improved handling.

      220 In 1957, Chevrolet used another basic device, a simple, flat, steel steering adapter, to improve steering response. The same steering box and pitman arm remained, but an extension was clamped to the center steering arm at the frame crossmember. The altered pivot points changed the steering ratio from 21:1 to 16.6:1. Only 3.7 turns were needed to go lock to lock, but the setup increased steering effort during parking maneuvers so much that General Motors restricted installation only to cars ordered with the RPO 684 heavy-duty brake and suspension option.

      221 The first wheel-cover redesign in three years was in 1959. Although it was almost identical to the pressed stainless-steel units used since 1956, the flat span between each of the 10 “spokes” was pierced with a 2.0 × .5-inch rectangular vent. It may sound laughable in our modern world of aluminum and even carbon-fiber wheels, but the 10 vents eliminated the heat-trapping effect of previous non-pierced, full-sized wheel covers. Working with the four air gaps formed by the union of the wheel spyder and hoop, the heat generated by the brake drums finally had free passage to the outer face of each wheel. That said, the big-brake and 15 × 5.5-inch wheel options continued using the small passenger-car center caps, which provided unrestricted airflow to carry away brake heat.

      222 One iconic sports-car detail that Corvette never pursued was wire wheels. Installed as original equipment on many British and Italian icons such as the Jaguar XK120, MG TC, and Ferrari 250GT, wire wheels lacked the brute strength to handle the Corvette’s torque-rich V-8 engines. Although the extra spokes bolstered strength, the added mass quickly neutralized any benefit in unsprung mass. Although several Corvette show cars were fitted with wire wheels, they were never offered as a factory option.

      223 German sports-car manufacturers Porsche and Mercedes-Benz also largely ignored wire wheels on their production offerings, as well as on their factory-sponsored race cars from the 1946–1962 era. Instead, their sports cars (550 Spyder, 356, 300SL, etc.) used wheels made of steel, aluminum, or magnesium. And while Corvette hesitated until 1963 before offering optional aluminum wheels (with the controversial P48 knock-off wheel option; see Chapter 3), Corvette racers seeking improved power-to-weight ratios turned to aftermarket wheel makers such as Halibrand. In fact, Arkus-Duntov himself turned to Halibrand magnesium wheels for the 1957 Corvette SS race car (aka the XP-64).

      224 The 1957 Corvette SS factory race car marked the first appearance of the SS nomenclature on any Chevrolet vehicle. Destined to be immortalized on subsequent, and beloved, offerings such as the Chevelle SS396, Impala Super Sport, Monte Carlo SS, Camaro SS, and many others, it is surprising that Chevrolet never offered the Corvette with the fabled Super Sport script and performance-/image-boosting items. The Corvette SS was strictly an in-house engineering mule that competed in professional race events before the implementation of the June 1957 AMA performance ban.

      225 Posi-Traction was a controversial option when it first appeared in 1957 amid the murky clouds of the AMA performance and racing ban. Although it was meant to deliver power to both rear tires, the resulting tail-happy burnouts weren’t conducive to the anti-racing theme of the day. To soften the message, Chevrolet took pains to suggest that Posi-Traction was aimed at making travel safer during snowy winter weather. Although Corvettes and snow went together like submarines and screen doors, buyers quickly registered the Posi-Traction message. Ever-growing buyer take rates completed the story: 1957 = 2,099 out of 6,339 cars, 1958 = 4,011 out of 9,168 cars, 1959 = 4,170 out of 9,670 cars, 1960 = 5,231 out of 10,261 cars, 1961 = 6,915 out of 10,939 cars, and 1962 = 14,232 out of 14,531 cars.

      226 The May 1955 issue of Motor Trend set tongues wagging with this Rumor Mill column nugget: “The Chevrolet Corvette may drop fiberglass for 1956 production. The excellent quality of current Corvette bodies is achieved at too high a price (not passed on to consumers). Hand finishing of the plastic coupled with a high parts-rejection rate are the trouble-causers. Corvette is in the sports-car field to stay, so steel is the next big step.” Needless to say, it was not to be.

      227 In the October 1956 issue of Hot Rod, writer Racer Brown evaluated an early-production 1957 Corvette equipped with the optional metallic brake linings and wrote, “You just stand on ’em and they bring the car down to smooth, straight-line, nonskid stops from high speeds. We tried this with our test car more than 20 times in a row without any appreciable fade.”

      228 Despite a few cooling-off periods where General Motors voluntarily chose not to publicize Corvette’s winning ways on racetracks across the globe, the very first magazine ad that blatantly depicted a Corvette in sanctioned competition was the famed “Real McCoy” ad of mid-1956. Celebrating Corvette’s first-ever entry in world-class SCCA competition, the ad took aim at the Ford Thunderbird: “Other people make a luxury car that has much the same dimensions as this. That’s not so tough. And the Europeans make some real rugged competition sports cars, and that’s considerably tougher. But nobody but Chevrolet makes a luxury car that’s also a genuine 100-proof sports car. It’s a wicked combination to work out, and we didn’t hit it overnight.” The ad’s main image showed a stripped-down Vette with a grill-less gaping maw, auxiliary driving lights, and racing stripes that forever changed the way Corvette was seen and marketed.

There’s no doubt...

       There’s no doubt that the appearance of Ford’s 1955 Thunderbird halted plans to discontinue the Corvette despite a disastrous 1954 retail showing. That said, the only place for the T-Bird in the SCCA realm was in the spectator parking lot.

      230 Showcasing automobile-accident trends and statistics since 1931 (except during World War II), The Travelers Insurance Companies of Hartford, Connecticut, published an annual booklet titled Heedless Horsepower. The 1957 edition of this 30-page study appeared at the height of Detroit’s infatuation with advertised power ratings and just in time for Corvette’s historic shattering of the 1-hp-per-cubic-inch barrier with the Ram-Jet 283. Heedless Horsepower was packed with grim statistics citing the predictable linkage between youth, speed, powerful cars, and accidents.

      231 Blending fear-mongering propaganda with tragic facts, the 1957 edition of Heedless Horsepower warned, “In the year 1956, [when] the Age of the Automobile came into its own, automobile manufacturers fashioned dreams of steel: powerful, sleek, multicolored models with push-button

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