Disappointed by the poor results of the 917 in 1969, and facing new competition, Porsche concluded an agreement with John Wyer and his JWA Gulf Team, which became the official Porsche team, and also the official development partner. During tests at Zeltweg, where the car had won its only race at that time, Wyer’s engineer John Horsmann had the idea to increase downforce at the expense of drag. A new wedge-shaped tail was molded with aluminium sheets taped together. This new short tail gave the 917 much needed stability. The plastic engine intake cover had already been removed. The new version was called 917K (Kurzheck).

In addition to the 917, the lightweight and compact Porsche 908/3 were developed for the slow and twisty tracks of Nürburgring and Targa Florio, providing wins while the factory-backed 917 remained in the garages. The 908/3 was built to the FIA’s 3 litre Group 6 Prototype regulations whereas the 917 was now officially a Group 5 Sports Car following another FIA review of its racing classes, applicable from 1970.

Wyer was surprised to discover that another team was carefully preparing for the 1970 24 Hours of Le Mans with close support from Porsche. As in 1969, the Porsche Salzburg team was a de facto second works team under control of members of the Porsche family. The Martini Racing team also gained some support from Porsche AG; obviously Porsche made efforts to win the race by supporting more than one team.

Also, a new low drag version of the 917 was developed for Le Mans with support from the external consultant Robert Choulet. The 917LH (Langheck) featured a spectacular new “Long Tail” body including partially covered rear wheel arches which had very low drag, yet better stability than the 1969 version. A few 4.9 litre engines, introduced at 1000km Monza, were available for some cars, but these proved to put too much strain on the gearboxes.

The favorite team to win, Gulf-backed John Wyer Automotive, lined up three 917Ks, two with the 4.9 litre engine and one with the 4.5 litre unit.

Two 917 LH were entered in Le Mans, one in white and red trim by Porsche Salzburg. Driven by Vic Elford and Kurt Ahrens, the pole sitter’s 4.9 litre engine failed after 225 laps. Both drivers had also been entered on the team’s other car, a red and white 917 K with the standard 4.5 litre engine, qualified by Hans Herrmann and Richard Attwood on rather low 15th spot, but they did not drive after their own car failed.

The other LH was entered by Martini Racing, qualified by Willy Kauhsen and Gérard Larrousse on 12th position. The spectacular livery of this car was an elaborate whirls and swoops of light green on a dark blue background. The car with the regular engine gained the nickname of the Hippie Car or the Psychedelic Porsche from the team and media.

Early in the race, most of the works Ferrari 512 entrants eliminated each other in a shunt. The two Porsche factory teams, Gulf-Wyer and Porsche Salzburg, continued to battle each other, but all Wyer cars were out after 12 hours. At the end it was the red and white #23 917K of Porsche Salzburg, with the standard 4.5 litre engine, carefully driven by Stuttgart’s own Hans Herrmann and Englishman Richard Attwood through the pouring rain, that finally scored the first overall win at Le Mans, in a wet race that saw only 7 ranked finishers. Martini’s blue 917LH with a green “psychedelic Hippie” design came in 2nd. Both cars were later paraded across Stuttgart. To complete Porsche’s triumph, a 908 came third, a 914 sixth, and a 911S seventh, beaten only by two Ferrari 512.

Towards the end of the 1970 season, Ferrari entered some races with a new version of the 512, the 512M (Modificata). The 512M had a new bodywork built on the same aerodynamic doctrine as the Porsche 917K. At the end of 1970 the 512M was faster than the 917s.

During the 1970 season the FIA announced that Group 5 Sports Cars would be limited to a 3 litre engine capacity maximum for the newly renamed World Championship of Makes in 1972, so the big 917s and 512s would have to retire from the championship at the end 1971. Surprisingly, Ferrari decided to give up any official effort with the 512 in order to prepare for the 1972 season. A new prototype, the 312 PB, was presented and entered by the factory in several races. But many 512s were still raced by private teams, most of them converted to M specification.

Having still some of their 25 cars remaining unsold, Ferrari offered them as a bargain for customers at the end of 1970 – a consolation that had hardly been imaginable less than two years previously, when a 917 was offered for 140.000 DM. The original series of 25 flat-12 could not satisfy demand, and over 50 chassis were built in total. Porsche, an underdog for 20 years, had turned itself into the new superpower of sports car racing with the 917.

Notable technology includes a pure carbon fiber monocoque and subframe, dry sump lubrication and inboard suspension. The carbon fiber monocoque and subframe were produced and assembled by ATR Composites Group of Italy. The spoiler of the Carrera GT extends into the air when the car reaches about 70 miles (110 km) an hour and evens out the air flow, which causes less drag. The Carrera GT radiator is about five times the size of a 911 Turbo’s. Front and rear suspension consist of pushrod activated shock absorbers and dampers with front and rear anti-roll bars.