Porsche is returning to the top category of the famous endurance race classic at Le Mans and the World Endurance Championships (WEC) with its newly developed 919 Hybrid. The LMP1 prototype, designed for extreme efficiency, is said to be the most complex race car that Porsche has ever built.
The 919 Hybrid serves as a research platform for fundamental technology to be used in future production models, with its combination of two different energy recovery systems and a downsized turbo engine.
The drive system is based on a compact and lightweight 2.0 litre four-cylinder engine. It performs load-bearing functions within the chassis based on its V-construction, which also offers thermodynamic advantages. The petrol engine, which reaches a maximum speed of around 9,000 rpm, features direct injection and a single turbo.
There are also two different energy recovery systems at play. Fundamentally new is the recovery of thermal energy from exhaust gases. An electric generator is used here, powered by the exhaust gas stream.
The second hybrid system is similar to that in the Porsche 918 Spyder road car. Here, a generator on the front axle utilises braking phases to convert kinetic energy into electric energy, which is stored in water-cooled lithium-ion battery packs.
During acceleration, the front generator is operated as a single electric motor and drives the front wheels via a differential. This gives the 919 Hybrid a temporary AWD system of sorts, because the ICE directs its power to the rear axle.
The WEC enters a new era this season. LMP1-H prototypes will now be rated in direct relationship to energy efficiency. Permitted fuel quantity per lap is down by around 30%, while the amount of energy from the obligatory hybrid systems has been significantly increased.
This shifts technology into the limelight, tech that can be useful for future production vehicles. This relevancy is the reason for Porsche’s return to the pinnacle of sports car racing.
But can Porsche’s rookie race car beat the formidable Audi R18 e-tron quattro? It’s a tough ask, but anything is possible in this season of change. WEC 2014 starts on April 20 at Silverstone.