Porsche 919 beats F1 record at Spa
Porsche’s works driver Neel Jani has lapped Belgium’s legendary Circuit de Spa-Francorchamps in just 1:41.770 in a modified version of the 919 Hybrid that won the 24 hours of Le Mans three times in a row from 2015-2017. Jani’s lap time is some 0.783 seconds faster than the previous record which was set by Lewis Hamilton at the wheel of a Mercedes F1 W07 Hybrid, and secured him pole position for 2017’s Belgian Grand Prix. During his lap, Jani averaged 245.61 km/h (152.61 mph) and hit a top speed of 359 km/h (223mph).
The record was set in a 919 Hybrid Evo, a version of the WEC winning car that has been ‘unchained’ from the technical regulations established by the FIA and WEC to deliver close racing between the very different hybrids made by Porsche, Audi and Toyota. As such the Evo has, in addition to the developments prepared for, but never raced in 2018, several aerodynamic modifications.
The race car’s two-litre turbo charged V4 with its two energy recovery systems remained unchanged for the attempt. In the race car the combustion engine drives the rear axle while the electro motor boosts the front axle to accelerate the car with four-wheel drive. At the same time it recuperates energy from the exhaust system that otherwise would pass unused in to the atmosphere. The electrical energy that comes from the front brakes and the exhaust system is temporarily stored in a liquid-cooled lithium ion battery.
In preparation for the record attempt however, Porsche did away with fuel flow limits that were required by the WEC efficiency regulations. At the 2017 championship round in Spa, in the Porsche 919 Hybrid’s final season, it could use 1.784 kilogram/2.464 litres of petrol per lap. The V4 combustion engine’s output back then was around 500 hp. Freed from these restrictions and equipped with an updated software package the 919 Hybrid Evo delivers 720 hp. In addition, the amount of energy from the two recovery systems was upped. At the Spa round of the WEC in 2017, the car could use just 6.37 megajoules, which was far below the systems potential. For the lap record, Neel Jani was able to use a full boost of 8.49 megajoules, increasing the output by 10 per cent from 400 hp to 440 hp.
Porches engineers also freed the aerodynamics from the WEC regulations. The new larger front diffuser now balances the new and very large rear wing, both of which have actively controlled drag reduction systems. The hydraulically operated systems trim the trailing edge of the front diffuser and opens up the slot between the rear wing main plane and the flap respectively in order increase the aerodynamic efficiency of the Evo. Underneath the Evo the turning vanes and floor have been optimised with fixed height side skirts to increase the aerodynamic performance again as efficiently as possible. In total the aero modifications resulted in 53 per cent higher downforce and an increase in efficiency by 66 per cent compared to the trim used in the 2017 qualifying at Spa.
Other changes made to hit that one hot lap was a significant weight reduction programme, with everything on the car that would not be needed on a single fast lap being removed. The removal of things like air-conditioning, lights, the windscreen wiper, and the pneumatic jack system meant that the dry weight of the car was reduced by 39 kg to just 849 kg. The Evo also gained a four-wheel brake-by-wire system to provide additional yaw control, its power steering was adapted for the higher loads and stronger suspension wishbones were implemented. Lastly, Porsche also worked with tyre partner Michelin to develop new, grippier compounds.
“The 919 Evo is brutally impressive. It is definitely the fastest car I ever drove,” asserted Jani “The grip level is at a fully new dimension for me, I couldn’t imagine this amount beforehand. The speed on which everything happens on a single lap with the 919 Evo is that fast that the demand on reaction speed is very different to what I was used to in the WEC. We are not only faster than the F1 pole from 2017. Today’s lap was twelve seconds faster compared to our WEC pole position from last year! We have had three very intense days at Spa. Today I knew on the very first lap in the morning that the car’s performance was super. The race engineers did a great job setting up the car and the Michelin tyres are sensational.”