A rally is often more than just the days of…
First win for the Porsche 919 Hybrid: driving the innovative Le Mans prototype, works drivers Romain Dumas (France), Neel Jani (Switzerland) and Marc Lieb (Germany) won the São Paulo six-hour race on Sunday. It was the eighth and final round of the FIA 2014 World Endurance Championship (WEC). After being away for 16 years, it was only at the start of this season that Porsche returned to the top category of endurance racing.
A high tempo had already been a feature of the development process – the period between taking the decision to return to the top level of the sports car world championship in 2011 and the Porsche 919 Hybrid appearing for the first time on the company’s in-house test track on 12 June 2013 was less than two years. During this period, a new office building and a workshop for the class 1 Le Mans prototypes (LMP1) were built at the Porsche Development Centre in Weissach.
The team grew from zero to 230 motor racing experts, around 150 of them engineers. Machines, materials and components were procured, ranging from high-voltage equipment to a driving simulator. The most complex racing car that Porsche has ever built was produced in record time. Leading the Porsche team are Fritz Enzinger (LMP1 Project Leader), Alexander Hitzinger (Technical Director) and Andreas Seidl (Team Principal).
On its race debut at Silverstone (England), the team immediately achieved a first podium finish. That was followed at the second six-hour race in May at Spa-Francorchamps (Belgium) by a first pole position. At the 24 Hours of Le Mans (France) a 919 Hybrid had been leading for a total of 37 laps, but then – lying in second place a good two hours from the finishing line – retired with an engine problem. After a long stop for repairs, the team’s other car came home in eleventh place overall and fifth in its class.
In the chaotic weather conditions of the race in Austin, Texas (USA), in September a 919 Hybrid was once again on course to take the race win when a technical problem led to a loss of power. In Fuji (Japan) in October, as well as in Shanghai (China) in November, the team enjoyed two straightforward six-hour races and was rewarded with two more third place finishes, while the 919’s second pole position in Shanghai was another reason to celebrate. The seventh outing for the newly developed prototype in Bahrain brought the next step forward: pole position number three was followed by having both car crews on the podium for the first time. At the finale in São Paulo, with the maiden win Porsche ultimately climbed up to the highest step of the podium. Interlagos also saw both Porsche 919 Hybrids locking out the front row of the grid for the first time.
Breakthrough for pioneering hybrid drive system
No other prototype in the starting field for the 2014 World Endurance Championship has a hybrid system as efficient or complex as that of the Porsche 919 Hybrid. The race car is pioneering new technologies for future sustainable drive systems to be developed by the sports car manufacturer. The World Endurance Championship’s new efficiency rules, which prescribe a set amount of energy per lap, offered for Porsche the decisive technological challenge to prompt a return. Developing and implementing appropriate solutions in house was a logical consequence.
Everything on the Porsche 919 Hybrid is dedicated to the dictat of extreme efficiency with maximum performance. This includes both the aerodynamics and the selection of materials for the lightweight construction. The most spectacular aspect, however, is the powertrain concept with its extremely compact two-litre, four-cylinder turbo engine and two energy recovery systems. The drive systems of LMP1 vehicles entered by car manufacturers must as of this year be hybrid in design. The rules, however, do not specify ‘how’ this is to be achieved. Number of cylinders, cubic capacity, diesel or petrol – are all left up to the teams. The limiting factor is the amount of power available per lap. That applies both to the amount of fuel and to the electrical power that can be drawn from the storage systems.
On the 919 Hybrid these consist of liquid-cooled lithium-ion battery cells, which are fed from two systems: during braking, kinetic energy gets converted at the front axle into electric current, while at the back usable electric power is gained from exhaust energy. This recuperation of thermodynamic exhaust energy is unique in the starting field for the sports car world championship. In this approach an additional turbine generator set practically replaces the wastegate. Porsche makes use of this excess exhaust gas: it drives a second turbine and thus also a generator that produces electric power. Previously lost energy is put to good use. Thanks to the exhaust gas energy recovery system the Porsche 919 Hybrid is the only car in the field that regenerates energy not only when braking, but when accelerating as well.
The objective for the FIA rules of reducing the fuel consumption of the prototypes year-on-year by 30 percent has been achieved. En route to its first victory the Porsche 919 Hybrid clocked up 2,323 kilometres as the race leader. Over the eight races the two prototypes completed 23,232 kilometres in total. In the process they produced and used approximately 3,592 kWh of electric energy. That is enough to cover the electricity requirements of an average German household for 373 days or more than a year.