Not Exactly a Webster’s Definition – A History Lesson
© Janos Wimpffen

Prior to the 51st running of the Sebring 12 Hours, Janos Wimpffen explains the multitude of post war changes that have brought us to where we are now, with the two prototype classes running under the ACO’s regulations.

We have come to take for granted that when the start of the major sports car season rolls around—now almost universally accepted to be Sebring, there are immediate discussions about the entries and prospects for first the Prototypes and then the GTs. We’ve come to realize that the cars are quite different. But how did it come to be this way?

To paraphrase a certain well-read book in the public domain, in the beginning there was only sports car racing. Our favorite branch of motor sport has always been distinct from other disciplines, such as single-seaters and oval track racing, in that sports car races nearly always include more than one class of car, resulting in competition for both the overall and category awards. But those class systems were much more basic in the past.

The modern era of sports car racing began once the dust of WWII was cleared. Nearly always, the only differentiation was between relative engine displacements. The popular class breaks during the late 40s and early 50s came at 5000, 3000, 2000, 1500, 1100, and 750 cc limits. Some sanctioning bodies, like the SCCA, attempted to lump cars together based on a cocktail of performance characteristics. However, there was seldom consideration given to the number of cars produced or the relationship between the racers and their cousins on the road. Remember, this was an era when even at Le Mans most teams drove their entries cross-country on public roads, before the driver simply strapped on a helmet and took his place on the starting grid. The ethos had always been that sports car racing was merely a competition for road going high performance autos.

This began to change as small, but growing, constructors such as Ferrari and Porsche, as well as then well-established companies such as Mercedes and Jaguar, became more and more involved. Similarly, there were new marques appearing such as Cunningham and Allard. It became exceedingly clear that the examples brought to the track by factory teams and well-heeled privateers had decreasing resemblance to the garden variety 356s, 300SLs, and XK120s that you or I could buy at our nearby dealership.

This evolved into a distinction between a category for “Sports Cars” and another for “Series Sports Cars.” The latter category would soon come to be known as Grand Touring, in deference to the Italian invention of the Gran Turismo, applied to production versions of 1950s three-liter Ferraris and Lancias. The 1957 edition of the 12 Hours was the first time that the Sports / GT split applied to Sebring, although interestingly it was not used officially at Le Mans before 1959.

The premier category was recognized as a haven for thoroughbred race cars, while the latter was for road cars modified (lightly) for competition. Today’s LMP 900 and LMP 675 classes are direct descendants of the 1950s “Sports Cars.” Of course, the details of the rules have changed constantly, as has the technology. Throughout much of the 1950s and 1960s there was an ongoing debate about whether the Sports Car category should be allowed to stretch further away from any pretense at having connections to road cars. They were required to come from recognized manufacturers and for many years they had to carry a spare tire and a luggage compartment. One constant has been that sports cars by definition must be full-bodied and have space for a passenger.

Sebring had been part of the World Championship of Sports Cars since 1953. Until 1958 there was no displacement limit placed on the main Sports class. This was the era of the big Cunninghams, D-type Jaguars, Ferrari 375s, and the Maserati 450S. Cost and safety concerns brought about a three-liter limit from 1958 through 1961. There was increasing concern that the cars were evolving too far from road machines and various rules were introduced, such as a minimum windshield height. This generated oddities such as the Maserati Birdcage.

By the early 1960s, GT cars had become increasingly prominent at most rounds of the series. The FIA had grown tired of tweaking the rules for the Sports class and decided that from 1962 forward the world championship would revert to the Grand Touring class. The organizers of the principal races in the series revolted and formed their own Challenge Mondial. This would include the classic endurance rounds of the era, the Sebring 12 Hours, Sicily’s Targa Florio, the Nürburgring 1000 Kms. and the 24 Hours of Le Mans.

While these races also included GT cars, the move to retain the more pure race cars was fortuitous, as it coincided with the dawn of such concepts as rear-engined designs and sleeker aerodynamic approaches. The Chaparral, Ferrari TRs and P series, Cooper Monaco, Lola GT (right), and others came about during the early 60s.

It also a time when a subtle distinction was made between the Sports category and a new one originally called “Experimental Prototype”, then “Prototype GT” and finally simply Prototype. The Sports class, later Sports-Racing, referred to cars built purely for racing with no pretense as a road car. This is where the one-off constructors were placed. Major manufacturers were classified into the Prototype class. Now, if you check your dictionary, the definition for prototype discusses the notion that it should be the first test example of an item intended for mass production. However, such a direct linkage was, and has, never been clearly enunciated in the rules of sports car racing. The Prototype category simply became a haven for the furthest expression of the sports car art.

Small displacement classes of Sports-Racing and Prototypes were also very popular throughout the 1960s. The fields were filled initially by various Porsches, Alfa Romeos, and Abarths, and in later years by Lolas and Chevrons.

The two-year period of 1966-1967 was one of the apogees of Prototypes, as once more the displacement limits were removed. The seven-liter Ford Mk IV that conquered Sebring and Le Mans was the result. The Le Mans organizers, the ACO, lobbied for an engine size cap for the championship, with the thinly veiled purpose of hoping that French manufacturers would have a better shot at the title. Ironically, the 1968-1975 period marked an era when the Prototype class was intentionally made to consist of pure race cars. A three-liter limit was introduced, making the engines and chassis nearly identical to those in use in Formula 1. The Ferrari 312, Matra, and Alfa Romeo 33/3 were the key competitors under those rules.

Almost as an aside, the FIA included a separate Sports class for 1968-1971. This would have a five-liter limit and was intended simply as a field filler, since there were a host of Ford GT40s and other cars with American V8s available. The Prototype class never had a minimum production requirement, but again with the road car pretense, the Sports category called for 25 identical units to be built. There was nothing to preclude producing a new car and Porsche responded by building the awesome twelve-cylinder 917 and Ferrari introduced the 512. Both cars featured prominently at Sebring during what is regarded as sports car racing’s golden era.

Sebring lost its World Championship status after 1972 and was picked up by the fledgling International Motor Sports Association, as the premier round in its GT championship. It would be open only to Grand Touring (and some Touring) cars from 1973 to 1977, before the race, and IMSA, regained international standing in 1978. This coincided with the introduction of the GTX (GT Experimental) class that was IMSA’s answer to Group 5 which had been the norm in the sports car world for several years. These were silhouette versions of supposedly production-based cars. The Porsche 935 was the dominant car of this period.

True prototypes returned to the forefront in 1982 when both the FIA (with Group C) and IMSA (with GTP) introduced the new coupe-bodied ground effects cars that captured the imagination for a decade. The Porsche 962, the Jaguar XJR series, Nissan GTPs, and Eagle-Toyotas were the most successful of the new breed of prototypes. This was also a period of a very strong “baby” class with the GTP Lights in North America and Group C2 versions in Europe.

Increased costs and dwindling entries led to the replacement of GTP with the World Sports category of 1994. Bodies were now open topped and the undertrays were required to be flat, doing away with ground effects. Engines were supposed to be production based, but as a measure to increase the class’ stature, a not yet readily available twelve-cylinder Ferrari was allowed to participate, ushering in the famous 333SP.

The LMP class of today was introduced in 1999 and is mostly an evolutionary development of WSC. There were slight changes in rules that made the older WSCs less competitive and in some cases obsolete, while the growing participation of major manufacturers such as BMW and Audi raised the bar with ever more sophisticated designs.

That has been the nature of the game throughout the post-war history of sports car racing. Whether you call them Sports, Sports-Racing, Experimental, or Prototype, they have always been pushing the envelope of two-seater racing.

Some brief historical facts about Prototypes at Sebring; as noted, 1957 was the first year that the Sports vs. GT distinction was applied at the 12 Hours. Since then there have been 2858 starters up through last year’s edition. Of those, 1023 or 36 percent were Prototypes / Sports-Racers / WSC, or some other “premier” class such as the GTX cars of the late 1970s. There were 1974 starters (69 %) in the GT classes, and 125 (5 %) from Touring categories allowed during a handful of years. Sports / Prototype cars won each edition from 1957 through 1972. GTs won, of course, from 1973-1977 when they were effectively the only contestants. GTX, GTP, WSC, and LMP cars won during their respective periods, except for 1983 and the WSC’s initial season of 1994 when GT cars again won overall.