The interruption of Porsche's Sebring supremacy proved brief, as 1976 brought the first of three straight wins for the 911. Once again BMW and promoter Greenwood led the anti-Porsche challenge, the latter's Corvette taking pole with a new track record and leading the early stages before slipping back. David Hobbs and NASCAR's Benny Parsons then took over the lead with their BMW, but were thwarted by mechanical troubles, leaving Al Holbert and Michael Keyser to cruise to a two-lap triumph with their Carrera. Next year's win went to the similar car of George Dyer and Brad Frisselle, after the new – and much faster – Porsche 934 turbos that dominated the early going retired.
The bigger news came off the track as Greenwood – increasingly frustrated with the thankless task of operating the race under constant pressure from the aviation authorities and complaints about the track's crumbling infrastructure – ended his involvement. But another competitor, Charles Mendez, stepped in to take over promotion of the race and launched a series of track improvements for 1978, including repaving and upgraded safety barriers. A new era was ready for launch – and Porsche was ready to provide one in the shape of its new 935, which would eventually surpass the record of the Ferrari 250TR for Sebring domination.
Eight of the new Porsches were on hand for the '78 race, although they were bested in qualifying by the McLaren-run BMW 320i, which broke the track record by 8mph (!). The race, though, was an all-935 battle, with Dick Barbour's entry driven by Brian Redman, Bob Garretson and race promoter Mendez (LEFT), taking the win.
Incredibly, Porsches would rule the roost at Sebring for the 13 years, with a string of triumphs by the 935 broken only by a GTO-class 934 scoring the overall win in 1983, driven by Wayne Baker, Jim Mullen and Kees Nierop, before Porsche's take on the new generation of IMSA's Camel GT prototypes – the mighty 962 – moved to the fore.
Prototypes had been gradually expanding their footprint in IMSA competition since 1981, although the more reliable Porsche GT cars continued to dominate the enduro events like Sebring. But by the middle part of the decade, the GTPs had taken over, and dominated the front at Sebring. Despite massive attrition for the 1985 race – nearly half the field had dropped out by the halfway mark – the Porsche 962s maintained their grip. Preston Henn's Swap Shop entry, driven by Bob Wollek and A.J. Foyt, had not been among the quickest 962s, starting only 13th, but surged forward as the race progressed, picking up the lead at the seventh hour and the withstanding gearbox problems to take the win. Foyt's victory made the Indy 500 legend one of only five drivers to win Le Mans, Sebring and Daytona, and would also prove to be the last major race win of his amazing career.
For 1986, Whitney Ganz made it one for the books by shattering the lap record in his March-Buick GTP, setting a pole-winning lap of 133.134mph. In the race, though, it was left to Porsche 962 runners to fight for the win. Three 962s battled up front before two were shaken apart by the rough runways. The last Porsche standing – driven by Bob Akin, Hans Stuck and Jo Gartner – had a fright of its own when it lost its left-front wheel on the last lap, but with the luxury of an eight-lap lead they were able to limp home to victory. It was a fitting “walking wounded” send-off to Sebring's unforgiving runways.
The following year, as the Federal authorities were again demanding that Sebring end racing on active airport runways, a substantially revised Sebring circuit dispensed with most of the World War II concrete in favor of a shortened (4.11-mile) layout running primarily on asphalt. (It would be shortened again in 1991 to its present 3.7 miles via tweaks that opened up the whole track to spectators). Although speeds were down, the new track was easier (or, rather, less hard) on equipment. The winning car – a 962 again, of course – of Bobby Rahal and Jochen Mass averaged 102mph for the 12 hours, some 13mph slower than the previous year's winner.
Porsche's domination at Sebring lasted one more year, as the 962 model withstood the new challenge of Tom Walkinshaw's Jaguar team, with Hans Stuck and Klaus Ludwig scoring a nine-lap victory (RIGHT) in the same car that had won the previous 12 Hours. For 1989, however, they had a new challenge in the form of the Electramotive Nissan GTP.