MONZA, Italy – Porsche revealed the new 919 Hybrid that the manufacturer will campaign in the FIA World Endurance Championship this year on Friday at Autodromo Nazionale di Monza.
“Each and every one of the nine endurance races presents a challenge,” said Fritz Enzinger, vice president LMP for Porsche. “Reliability is the basic requirement; six hours of navigating around the many cars in the different categories, each driving at different speeds, makes each race unpredictable – and ultimately it is often only seconds that separate the winner from the rest of the field. At four times the duration of the other races, Le Mans forms the pinnacle of the series. This 24-hour race pushes both men and machine to their absolute limits. Toyota is set to be a very strong contender in the top-tier LMP1 category for the 2017 season. We will face up to them with a meticulously enhanced Porsche 919 Hybrid and a team of six first-class drivers.”
The newmodel of the Porsche 919 Hybrid deploys a range of new innovations, particularly in the vehicle’s aerodynamics, the chassis and the combustion engine.
“For the 2017 season, 60 to 70 per cent of the vehicle is newly developed,” said Team Principal Andreas Seidl, who also currently serves as the technical director. The basic concept of the 919 Hybrid still offers scope to optimise the finer details and further boost efficiency. The monocoque has remained unchanged since 2016, but the optimisation potential of all other components was analysed and, in most cases, adjustments made accordingly.”
The technical regulations for the FIA World Endurance Championship introduced further limitations in terms of the dimensions of some body components that affect aerodynamics. In an effort to increase safety, the new measurements reduce the downforce of the LMP1 prototypes, which in turn lowers the vehicle’s cornering speed for safety reasons.
Based on the new specifications and developmental findings, the Porsche engineers devised two brand-new aerodynamics packages for the 919 Hybrid – driven, of course, by a desire to compensate for the increased lap times resulting from the regulatory requirements.
In 2016, Porsche delivered three aerodynamics packages for the season, but the new regulations have also imposed limits on numbers.
“Limiting teams to two aerodynamics packages per season is a sensible cost-control measure,” said Seidl.
One of the new aerodynamics packages is specifically designed for the high-speed track at Le Mans. To achieve maximum top speeds on the extremely long straight sections, the package focuses on minimising air resistance. The second aerodynamics package compensates for a higher level of drag with greater downforce for tracks with twists and turns.
A key focus for the engineers was to design the front end of the vehicle to be less aerodynamically sensitive.
“In 2016, the front end of the vehicle was accumulating small amounts of abraded rubber from the track surface. This rubber built up and upset the balance of the vehicle. We analysed this phenomenon and optimised the relevant bodywork components,” said Seidl.
As part of the package of enhancement measures, the Porsche engineers have boosted the efficiency and performance of the drivetrain. The transmission on the front and rear axle, the combustion engine, the electric motor and the energy recovery systems have all been optimised, but the basic principle behind the drive system is unchanged.
The rear axle of the 919 is driven by an extremely compact two-litre V4 combustion engine. The engine combines downsizing turbo technology with efficient direct fuel injection; it delivers just under 500 hp (368 kW) and is the most efficient combustion engine in the history of Porsche to date. Two different energy recovery systems – a braking energy recovery system on the front axle plus an exhaust energy recovery system – feed a lithium-ion battery, which in turn powers an electric motor capable of supplying additional power of over 400 hp (294 kW) to the front axle on demand.
The 919 Hybrid is the only prototype to recover energy during acceleration as well as braking. It achieves a system power of more than 900 hp (662 kW), profiting from the enormous traction generated when the car accelerates out of bends with a further 400 hp of power on the front axle, transforming the 919 into an all-wheel drive.
Approximately 60 per cent of the recovered energy comes from the KERS (Kinetic Energy Recovery System) on the front-axle brakes. The remaining 40 per cent is generated by the exhaust energy recovery system.
An average of 80 per cent of the braking energy recovered from the front axle is immediately converted to drive energy. If the combustion engine was required to supply this electrical power, it would need to boost its output by over 100 hp (74 kW), which would increase the fuel consumption of the 919 by more than 20 per cent.
At Le Mans, this would equate to an extra litre of fuel per lap. A further advantage of the highly efficient recuperation system is that it enables the 919 to perform with smaller and lighter brakes – a characteristic that not only reduces weight, but also air resistance, as smaller brakes require less cooling air.