For 2016, Porsche's goal is to continue reigning in the World Endurance Championship (WEC) and for that it made some important modifications to the already reliable 919 Hybrid that allowed it to win the specialty title last year and triumph in the 24 Hours of Le Mans, the most important date on the calendar.
The evolution of the hybrid for its third season in the WEC is based on a combination of well-proven factors and also various innovations.
Its base remains unchanged so that the chassis structure and hybrid drive concept with the 2-liter 90-degree V-turbo petrol engine and two energy recovery systems (from front axle braking and exhaust) remain. . However, the mechanics were adapted to comply with the new regulation that stipulates a reduction in fuel consumption to prevent the prototypes from becoming faster and faster cars.
In the last tournament, the output of the combustion engine was well above 500 hp. The 2016 regulations stipulate an even lower amount of fuel energy per lap and reduce the maximum fuel flow rate for all prototypes. For the 919 this means around 8 percent less fuel and power, or 10 megajoules less power per lap at Le Mans. That costs about four seconds for every 13.629 kilometers on the Le Mans circuit.
In energy recovery systems, Porsche was the first and only manufacturer in 2015 to be able to select the highest category of electrical energy, that of 8 megajoules per lap at Le Mans.
For 2016, the electrical components are more powerful and efficient. This is valid for the optimized electric motor on the front axle, the power electronics and the new generation of lithium-ion cells in the self-developed battery.
The kinetic energy produced in the front axle when braking is converted into electrical energy. The second recovery system is installed in the exhaust section, where the exhaust gas stream drives a second turbine, practically in parallel with the turbocharger.
The electricity produced, along with that generated by the kinetic energy recovery system (KERS) on the front axle, is temporarily stored in lithium-ion battery cells, available to the driver, who can activate the power when needed to complement the power of the combustion engine.
This power is applied to the front axle by the electric motor, and the hybrid 919 is temporarily transformed into a four-wheel drive car with a power system of around 900 horsepower.
Another critical decision for the 919 Hybrid was 800-volt high-voltage, a technology that series developers are embracing the Mission E, an advanced four-seater sports car.
The FIA regulations distinguish between four levels ranging from 2 to 8 megajoules (MJ) of deployment energy. The calculation formula is based on the 13.629 kilometer lap of the Le Mans circuit and the calculation is adjusted accordingly for the rest of the calendar.
If a team wants to use the 8 megajoules per lap that is allowable in the highest recovery category, an FIA flow meter device will limit the allowable amount of fuel per lap to 4.31 liters of gasoline (3,33 liters in diesel). In comparison, 4,70 liters of fuel (3,70 liters in diesel) can be used per lap in the 2 megajoule category. Engineers also have to take into account the fact that the most powerful energy storage and recovery systems are larger and heavier.
To improve driving dynamics, balance, traction, grip and configuration options, the 919 has received a new front axle and an optimized rear axle. This should make the car more forgiving and offer better handling overall. The brakes have also undergone improvements and the team expects an increase in performance from Michelin tires.
From an aerodynamic point of view, Porsche will start the season with a high load configuration, another for Le Mans with an extremely low load configuration and a third high load configuration for the remainder of the season. Regulations prohibit more than three aerodynamic settings per year.
While most of the enhancements to the 919 Hybrid are barely visible from the outside, the new headlights give the 919 a new look. The four-eye optics that distinguish it as a member of the Porsche Turbo family were retained for the most part, but the headlights are already equipped with significantly more LEDs, to ensure better illumination during nighttime periods at Le Mans, Austin. and Bahrain.
Three drivers share each vehicle in the World Endurance Championship, with Timo Bernhard, Brendon Hartley and Mark Webber driving the No. 1 prototype. The No. 2 prototype will be in the hands of Romain Dumas, Neel Jani and Marc Lieb.