In 1976, the Porsche engineers developed a race car based on the 911 Turbo, which was set to dominate the long-distance races of the FIA Group 5 Manufacturers' World Championship: the Porsche 935. The highlight of this development project was the legendary Porsche 935/78 from 1978 – the most powerful 911 of all time. The differences between this powerhouse - named "Moby Dick" on account of its wide, long-tailed body - and previous models were a modified frame, aerodynamically enhanced body and right-hand drive, among other things. With the aim of improving the performance and durability of the engine, the Weissach engineers developed a power unit that was destined to leave the competition standing. As previous models had encountered problems with cylinder head maintenance, these were now simply welded together. A compromise also had to be found for the cooling. So water cooled the heads, and air cooled the cylinders. With the newly-introduced four-valve technology, the six-cylinder horizontally opposed engine relied on two intercooled turbochargers. Increasing the displacement to 3,211 cm³ resulted in brute power of 845 hp. Due to its continued dominance, Porsche withdrew from the long-distance World Championship in 1978, meaning that "Moby Dick" saw only a handful of outings. At Le Mans, the race car managed an incredible 366 km/h on the Mulsanne Straight, but in the end its drivers, Manfred Schurti and Rolf Stommelen, only finished in eighth place, due to technical problems. The great successes of the Porsche 935/78 were not achieved until 1978 onwards, as part of the private Kremer team.