Porsche unveils the new Porsche 919 Hybrid for 2017
Fritz Enzinger, Vice President LMP, faces the season with a great deal of respect: “Each and every one of the nine endurance races presents a challenge. 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 technology of the Le Mans prototype
The 2017 model of the Porsche 919 Hybrid deploys a range of new innovations, particularly in the vehicle’s aerodynamics, the chassis and the combustion engine. Team Principal Andreas Seidl, who continues to serve as acting technical director, reports: “For the 2017 season, 60 to 70 per cent of the vehicle is newly developed. The basic concept of the 919 Hybrid still offers scope to optimize the finer details and further boost efficiency. The monocoque has remained unchanged since 2016, but the optimization potential of all other components was analyzed and, in most cases, adjustments made accordingly.” As in Formula 1, the monocoque is made from a carbon-fiber compound using a sandwich design.
In 2016, Porsche delivered three aerodynamics packages for the season, but the new regulations have also imposed limits on numbers. Andreas Seidl: “Limiting teams to two aerodynamics packages per season is a sensible cost-control measure”.
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 design focuses on minimizing air resistance. The second aerodynamics package compensates for a higher level of drag with greater downforce for tracks with twists and turns. Track-specific fine-tuning is still permitted, but in general, 2017 will involve a higher level of compromise than was the case with the three aerodynamics packages of the previous year.
A key focus for the engineers was to design the front end of the vehicle to be less aerodynamically sensitive. Seidl continues: “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 analyzed this phenomenon and optimized the relevant bodywork components.”
When comparing a front view of this year’s 919 to the previous year’s model, the higher, wider and longer wheel arches immediately catch the eye. To the side, the new channel from the monocoque to the wheel arch is visible, along with the redesigned rear air intakes for the radiators.
“As a result of the aerodynamic losses we will incur due to the new regulations, we are expecting to see a three to four-second increase in lap times at Le Mans,” explains Seidl. “We will have to wait and see how well the various enhancements we have made will compensate for these losses.”
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 liter 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.
Seidl: “Our aim was to ensure that the vehicle weight did not exceed that of the previous year’s vehicle, in spite of the innovative new technologies we added – from chassis and body elements to the powertrain updates.”
The 919 will start again in the highest energy efficiency class prescribed by the regulations. This means that the car can use 8 megajoules of recovered energy over the 13.629-kilometre (8.4 mile) track in Le Mans, subject to the restriction that it may only consume a maximum of 4.31 liters of fuel to do so. Both consumption values are closely monitored and totaled up after each lap.
Driving quality and tires
Alongside the mechanical enhancements made to the chassis, a number of software innovations have helped to further improve the driving quality of the 919, particularly in terms of traction control and hybrid management. Both of these factors have a significant impact on the service life of the tires, and this consideration is set to take on even greater importance in 2017. LMP1 teams will now have three sets of tires fewer available to them for each race weekend and car, so tire sets will need to withstand double stints of racing on a more frequent basis – lasting the equivalent of two tanks of fuel, or a driving time of around one and a half hours. Andreas Seidl: “Working together with our partner Michelin, we have prepared intensively so that we are able to keep up the pace right through to the end of the race, even when we’re driving in double stints. All the races, whether six hours or 24 hours in duration, will be real sprints to the finish this year, too.” During the night at Le Mans, when temperatures are cooler, even quadruple stints on one set of tires are possible.
WEC – the ideal platform for technological pioneers
With its unique efficiency regulations for Class 1 Le Mans prototypes (LMP1), the WEC represents an ideal platform for Porsche – and it was these regulations that fueled the company's return to elite motorsport in 2014. The regulations provide engineers with an unusual degree of freedom to introduce different drive concepts and require forward-looking technologies such as hybridization, highly efficient engine downsizing and consistent use of lightweight construction. As a result, the WEC provides the perfect platform for Porsche to develop and test innovations for road-going sportscars.
Prologue: the first meeting with the competition
From tomorrow, the first meeting of the WEC contenders is on. At the WEC’s so-called Prologue, there will be a total of 14 hours joint testing. On Saturday this also goes on for two hours after sunset. The Porsche LMP Team will run both cars on both days.
The hybrid racing car with starting number 1 will be driven by Neel Jani (33, Switzerland), André Lotterer (35, Germany) and Nick Tandy (32, Great Britain). Jani is currently joint WEC World Champion and 2016 Le Mans winner. Lotterer claimed the title of World Champion in 2012 behind the wheel of an Audi and brings with him the experience gained from three overall victories at Le Mans, while Tandy formed part of the winning 2015 Porsche team in Le Mans. The sister car with starting number 2 will be shared between 2015 World Champion Timo Bernhard (36, Germany) and the two New Zealanders Earl Bamber (26) and Brendon Hartley (27). Bamber claimed joint victory with Tandy at Le Mans in 2015, while the same year saw Hartley share the title of World Endurance Champion with Bernhard.
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