How Porsche Beat F1
The Story of The Porsche 919 Hybrid Evo
Porsche, one of the most famous automobile manufacturers in the world, has a rich history of racing, particularly endurance racing. With 19 wins at the 24 Hours of Le Mans, the German marque has cemented its place in motorsport history as the most successful constructor in the history of the iconic race. They have produced legendary cars like the 917, 911 and 944LM. With a stable full of Le Mans winners, they didn't need to build more. However, when Porsche announced their return to the World Endurance Championship after a 16 year absence in 2014, they decided to build an entirely new beast, the 919 Hybrid.
Porsche 919 Hybrid. Photo: Porsche
After a disappointing debut season where only one car finished at Le Mans, Porsche came back strong and dominated the race as well as the Championship for the next 3 years. Having had such a long string of success, Porsche decided to pull out of WEC at the end of the 2017 season and with it, retire the 919 Hybrid. However, before putting it under covers in Weissach, Porsche wanted to give their beloved car a fitting farewell and from there, the 919 Hybrid Evo was born.
The Concept
Once Porsche decided that they wanted to give the 919 a tribute, discussions on the best possible way to do that began in Weissach. The idea which was eventually agreed upon was to build an open-regulation version of the 919 and see what it could do. They decided to use the 2017 version of the 919 as a base for an LMP-1 car built without the restrictive regulations of WEC, a car aimed to go around the fastest tracks in Europe at an unprecedented speed and break lap records left, right and centre. The result was the 919 Evo.
Let's take a look at the details that made the Evo so special.
The Powertrain
The Evo had the same powertrain as the 919 since Porsche trusted their 2L V4 Hybrid power unit to be good enough to achieve the aim of the programme. There were some other changes to boost power from the 3-time Le Mans-winning engine. Porsche removed the fuel flow limit mandated by WEC to increase the output from the engine massively from 500 HP to 720 HP just from injecting fuel into the engine at a faster rate.
The engine of the Evo. Photo: Car Throttle
The 919 was the only hybrid LMP-1 car on the WEC grid. Porsche had created a very innovative system for energy recovery. The 919 and the Evo had one recovery mechanism to convert heat energy into electrical energy from the front end under braking and another system to recover energy while accelerating. However, a limit on the amount of power stored meant that the battery added only 400 HP. Removal of this limit enabled the battery to produce another 40 HP, adding an additional 440 HP to the 720 from the engine and taking the output of the powertrain to a massive 1060 HP.
The Energy Recovery System of the Evo. Photo: Porsche
Aerodynamics
At first glance, the aerodynamic structures on the Evo are very similar to the 919. However, on closer inspection, one can find many subtle but highly important improvements. At the front of the car, the nose was the same as the 919 but the bodywork around it was completely new. The side pods had bigger overhangs to reduce drag from the wheels. It had an active drag reduction system at the front as well as an F1-style DRS at the rear. Porsche also added skirts on the side, which are outlawed in every form of motorsport, to seal airflow beneath the car and increase downforce by a significant amount.
Porsche 919 vs The Evo, Aerodynamics. Photo: http://www.connectingrod.it/stampa_news.asp?id_news=229&lingua=en
The Evo has a much larger diffuser and a much bigger rear wing that is placed further behind from the one on the 919. This helps increase the performance of the diffuser. which was also opened up, and helps the rear end generate much more downforce as a whole. Porsche estimates that all these changes together help produce 53% more downforce on the Evo. Further, the active drag reduction apparatus helps reduce drag down the straights while increasing cornering speeds by producing greater downforce.
The shape of the rear wing was designed using AI. Photo: Porsche
An interesting thing about the Evo's aerodynamics is that it has been developed using machine learning. Porsche had to develop lots of new designs for the wings and other downforce generating structures, especially to use the DRS on the rear wing. To do this, they used machine learning models to design various aerofoil shapes based on different 'genes' or parameters. Once they had a few feasible designs, they used multiple algorithms to choose the best wing shapes for the Evo.
Hydraulics
There were quite a few additions to the hydraulic system of the car. As mentioned above, the DRS on the rear wing as well as the moveable trailing edge on the front splitter of the Evo were major upgrades made possible by the hydraulic system. Porsche engineers also managed to include a 4-wheel brake-by-wire system (or BBW). The BBW controls braking via the ECU of the car. When the brakes are applied, the ECU takes into account pedal position and pressure applied to determine the amount of braking required. Once this is determined, an electric pump pushes the required hydraulic fluid in the brake lines and produces braking.
Brake by Wire. Photo: https://www.semanticscholar.org/paper/Simulation-of-brake-by-wire-system-with-dynamic-Abeysiriwardhana-Abeykoon/55ac65d1fed89dcebb1f60a954f00e8a6682434b
The BBW system also enabled Porsche to use torque vectoring. Through torque vectoring, the amount of power reaching each wheel can be controlled and by optimising power delivery during different situations, Porsche achieved greater stability and better handling through the increased grip. Torque vectoring also helps control the amount of braking from each calliper. The power steering system was also updated to increase responsiveness and reduce issues while turn-in.
Weight Reduction
To save weight, Porsche removed things that it considered useless from the 919. This included headlights, windscreen wipers and pneumatic jacks used to make pitstops. This was possible since the cars didn't have to complete endurance races or run at night and thus, didn't need to be reliable. Driver comfort also wasn't a concern for the engineers as the car had to do only a couple of laps during any particular run. So they stripped down the cooling system and modified it to make it lighter, thus saving even more weight. Their efforts bore fruit and the Evo was about 39kg lighter than the 919 which meant that it had lower weight and much more power than a standard LMP-1 car.
The Evo lacks headlights and windshield wipers to reduce weight. Photo: Gruppe C / Tim Upietz
Tyres
Porsche teamed up with Michelin to produce a special race tyre for the Evo. The tyre was built using a very soft compound which significantly increased grip to make cornering faster. Though a softer tyre increases grip through a greater contact patch with the road, it also heats up faster. The temperature became such an issue that Porsche had to run the Evo early in the day at the Nordschleife just so that the car could make it around without the tyres overheating.
Suspension
Porsche needed to upgrade the 919's suspension system to withstand the additional load from the more powerful power unit and the greater downforce of the Evo. The engineers created new, stronger wishbones to increase performance and safety. The inboard suspension was made stiffer to prevent roll through corners and increase stability. They also updated the pitch-link suspension arms, which are similar to a pushrod suspension to absorb the added load, prevent excessive movement through corners and keep ride height as low as possible through corners for faster cornering.
The Evo features an updated Pitch Link Suspension
The Result
Once it was completed, Porsche took the Evo on The 919 Tribute Tour where it did demonstration laps at various circuits around Europe and U.S.A. In April 2018, Porsche Factory Driver, Neel Jani broke the lap record at Spa Francorchamps, Belgium by beating Lewis Hamilton's pole setting lap time from 2017 by 0.7 seconds. The lap time was faster than the 919's pole lap from 2017 by a whopping 12 seconds. Neel Jani described the car as a "bullet" after his lap record-setting run.
After setting the lap record at Spa, the Evo did several demonstration runs as part of the Tribute Tour. It did a few laps at the Nordschleife for the 24 Hours of Nurburgring, at the Goodwood Festival of Speed, The Festival of Porsche at Brands Hatch and at Laguna Seca during the Porsche Rennsport Reunion.
The 919 Tribute Tour at Nurburgring. Photo: Porsche
Initially, the Evo wasn't supposed to attempt a lap record run at the Nordschleife. However, after popular demand from fans, Porsche took the car to the 'Green Hell.' Piloted by Porsche Factory Driver Timo Bernhard, the Evo broke the long-standing lap record of Stefan Bellof in a Porsche 956 by nearly a minute, by setting a time of 5:19:546.
The Evo at the Nordschleife. Photo: Porsche
This is the story of the Porsche 919 Hybrid Evo, one of the fastest cars ever built. It is a fascinating tale of how the idea was born and how Porsche went about building the beast. It is really mind-boggling to see what the best designers and engineers in the world can do when given free rein.
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Comments (4)
I heard this story a lot of times but it’s still so impressive how they did it!!
I couldn't find the complete story in one place. Every piece I read had some more information. It is really fascinating
The fact that they wrecked the Nurburgring lap time around 5 minutes (I think) shocked me
Yeah, nearly a minute faster. That was really amazing.