Porsche served as the common denominator for winning cars in the endurance classics at Daytona and Sebring through the 1970s.
The 2014 Rolex 24 At Daytona will feature the debut of the Porsche 911 GT America, the latest edition in a legacy dating back to 1973 when Hurley Haywood and Peter Gregg drove a Porsche 911 RSR to victory in the Rolex 24 At Daytona and Mobil 1 Twelve Hours of Sebring Fueled by Fresh From Florida.
The Daytona victory was the first international triumph for a 911-based Porsche – beginning a long and successful legacy.
From 1970 through 1984, the 917s and models inspired by the 911 accounted for 21 of the 26 overall victories in the two Florida classics. "The 911 was – and is – a great car to drive," said Haywood, who scored four of his five overall Rolex 24 victories in that production-based car. "Back then, it was the car to drive because of its reliability. It was a really strong car, while the competition was not quite as reliable. The Porsche was not necessarily the fastest car on the race track, but it was certainly the most reliable."
The decade began in the aftermath of the scintillating Ford vs. Ferrari battles of the 1960s. While those exciting prototypes were eventually legislated out of competition, Porsche offered its 917K. John Wyer prepared winning cars for Pedro Rodriguez in both the 1970 and 1971 Daytona races, while Vic Elford and Gerard Larrousse won the 1971 Sebring event in a Martini & Rossi entry. Ferrari continued the heritage of the Sixties in the 1970 Sebring event, won by a team led by Mario Andretti in a 512S.
Both of the Florida races had the same winners in the GTU class for smaller displacement production-based cars – Gregg and Haywood in a Porsche 911. That was no surprise – Porsche 911s won in class in the four 24-hour races at Daytona from 1966 through 1969.
Five prototypes dominated the field for the 1973 Rolex 24, but it was a pair of Porsche 911 RSRs that dominated the race. Gregg and Haywood took the overall checkered flag for Brumos Racing when a similar RSR fielded by Penske Racing had a mechanical problem. Haywood and Gregg backed up their victory at Sebring, in a different RSR fielded and co-driven by Dr. Dave Helmick.
After both races were skipped in 1974 due to the international fuel crisis, Gregg and Haywood repeated at Daytona in a Brumos RSR. BMW briefly took the limelight at Sebring in 1975 and Daytona in 1976, but Porsches dominated both classics for the remainder of the decade – driven by either Haywood or Gregg in many cases.
Haywood co-drove a former Brumos RSR owned by Helmick in 1977. Gregg and Brumos won the following year in a 935, while Haywood took the 1979 race in a 935 co-driven by Ted Field and Danny Ongais. Sebring had RSRs win in 1976 (Al Holbert and Michael Keyser) and 1977 (Brad Frisselle and George Dyer), while the 935s began a five-year run at Sebring in 1978. The 1977 race saw Porsches sweep the top 10 positions in 1977, while the marque had a top-12 sweep there in 1979.
Porsche's reliability trumped tough competition throughout the decade. John Greenwood captured the pole and turned the fastest race lap at Daytona in 1975 in his Corvette, a showroom car that he rebuilt with plastic and space age materials. It led throughout the opening hour, only to succumb to a series of overheating issues eventually traced to the failure of a $3 part that could have been replaced in two minutes. Greenwood's Corvette also took third overall in the 1973 Sebring 12 Hours.
A Ferrari 365GTB Daytona took second overall in the 1979 Rolex 24. The car was driven by John Morton and Tony Adamowicz in honor of car owner Otto Zipper, who died suddenly the day before the race. An all-women team of Janet Guthrie, Lyn St. James and Bonnie Henn finished 17th in the 1979 Sebring race in a Ferrari Daytona.
At the end of the decade, Yojiro Terada led a factory lineup that finished fifth overall and first in GTU in a rotary-powered Mazda RX-7, setting the stage for that car's success in the following decade.
The Seventies had a few odd moments. The aforementioned 1974 fuel crises cancelled both races – although thousands of fans still went to Sebring for their annual celebration. The 1976 Daytona race was red-flagged for nearly four hours due to contaminated fuel, then turned back the clock one hour upon restarting the race. The race was still 24 hours in duration, though.
The 1976 Daytona race also included a number of NASCAR stock cars, part of the "Grand International" class added to that year's races at Daytona and Le Mans. Porsche swept the top-five positions in the 1977 Daytona race, with the streak broken by a Ferrari co-driven by famed actor Paul Newman.
Porsche's dominance didn't end with the close of the decade. Variations of the 935 won at Daytona through 1983 and at Sebring through 1984 (including a 934 in 1983). Mauricio DeNarvaez's victory at Sebring in 1984 was not the end of Porsche's domination – it was merely a changing of the guard.