Porsche 919 Hybrid
Porsche revealed an evolution of the 919 Hybrid on 11 April 2018, as it broke the lap record in Circuit de Spa-Francorchamps with a lap time of 1:41.77, with Neel Jani behind the wheel. The lap time was 0.783 seconds faster than Lewis Hamilton's flying qualification lap in 2017, previously posting a 1:42.553 in his Mercedes AMG F1 W08, a Formula One car. Jani was also over 12 seconds faster than the standard 919 Hybrid's 2017 pole position lap time of 1:54.097. During the lap, Jani's speed trap was at the Kemmel Straight, with an average speed of .
Porsche 917
The 917K was an evolution of the original 1969 car. After the first 917s were run in 1969, it was clear the car's aerodynamics made it nearly undriveable at higher speeds. After the 1969 championship season had finished, John Wyer requested a 3-day test session at the Austrian Österreichring (Zeltweg) course. The Porsche technical team turned out ready to do some serious panelwork on the coupe and in order to make a comparison, brought along the Can-Am 917PA Spyder. The drivers present instantly preferred the PA and together, the JW and Porsche engineers came up with the idea of a more upswept tail (as on the 917PA). The JW team had had similar high speed handling problems with the early Ford GT40 models. With gaffer tape and aluminium sheet a completely new short tail was evolved at the racetrack. This was quickly converted into a 'production' design back at Porsche and the 917K (Kurzheck) made its public debut at the 1970 season opening Daytona 24 Hours. Such was the improvement in the stability of the car at high speed, the 917K became the standard configuration for all races except Le Mans. This car was raced at every event by the two factory-supported teams (John Wyer Automotive and Porsche Salzburg) in the 1970 season except the Targa Florio and the Nürburgring 1000 km. The smaller, more nimble and generally better suited 908/03s were used for those races. The 917K won 7 out of 10 races; all the races it competed in. Later on in the 1970 season, the 4.5 liter flat-12 was bored out to 4.9 liters, then 5 liters.