Moby Dick: Porsche 935/78
The tale of a beast.
In 1976, the FIA introduced a new category allowing production-based vehicles to compete in the prototype class. The new class is called Group 5 "Special Production Car" category. Basically, the category is a precursor to the Group B rally cars. A race category with lenient rules creating the perfect circumstance for insanely fast, fire-spitting turbocharged monsters with wild bodywork design. The biggest difference is Group 5 competed mostly on tarmac circuits. The lenient rules consist of homologation requirements and aerodynamic limits where the entries must have a stock production body with various parts such as the hood and windscreen also derive from a production model. The category brought back the interest of both manufacturers and privateer teams alike.
In 1978, one engineer at Porsche pushed the Group 5 rules to the absolute limit and turning their already potent 935 into a monster.
That engineer is Norbert Singer, a genius on aerodynamics who played a fundamental role in many of Porsche's motorsport success since 1970 and a master at finding loopholes in the FIA rulebook.
For example, the FIA Group 5 rule allowed the door sills to be cut so front-engine layout cars can accommodate side-exiting exhausts. But the rule didn't specify to only front-engine layout cars nor how much of the door sill can be changed. Singer and Porsche took advantage of this by removing the door sills on the 911 entirely to lower the body by 8 cm for a better center of gravity. The Group 5 regulation also given full reign on designing the fenders to teams to accommodate the wider tracks. So Singer redesigned the fenders of the 911 to match the slope of the hood and relocating the headlights down to the bumper which helped improve the aerodynamic and downforce of the car. The rear fender was extended to obscene proportions in the name of streamlining. Pretty much any part of the stock 911 body Singer can stretch out while remaining in the boundaries of the regulation Singer did. It was one of the mechanics working on the car before race day commented it looks like "Moby Dick" the rest was history.
On the mechanic side, the new 935 switched to a right-hand drive configuration not only improved weight distribution but also driver’s sight as is more suitable for the clockwise direction of European circuits. Lesson learned from the previous iteration of the 935 plagued with gearbox reliability, the gearbox is now mounted upside down to reduce the angle of the drive shafts to improve durability. The flat-six engine got bored out from 2.8 to 3.2 allowing turbo boost to be raised as high as 25psi. The improvements to the engine for the 935/78 also introduced new water-cooled cylinder heads, a first for Porsche that significantly improved engine efficiency and doing away with a head gasket as the heads were welded directly to the cylinders. The engine can produce 845hp at maximum boost.
With that kind of flame-shooting power propelling such a streamlined machine only weighing in at 1000kg, the 935/78 was a force to be reckoned with. It can hit 60mph from standstill in 2.6 seconds, an impressive figure even in today's term. It clocked a top speed of 226mph down the Mulsanne Straight at LeMans, which is as fast if not faster than the Group 6 prototype at the time. With over 150 victories of various events under its belt and over 20 of those are class wins. It won both the 24 Hours of Daytona and 12 Hours of Sebring 6 times and also won the 24 Hours of Le Mans in 1979.
The Porsche 935/78 truly was as legendary as the mythical beast it got its name from.