Ahead of the 2016 FIA World Endurance Championship (WEC), Audi has unveiled the full details behind its comprehensively revised R18 LMP1 contender. The German brand states that the car has been redesigned from scratch, with ‘almost nothing in common’ with its predecessor.
The 2016-specification car features a more radical aerodynamics concept, including a new safety cell, its hybrid drive system is battery-operated for the first time, the V6 TDI engine has been revised, and new system solutions have been added.
At the heart of the concept is the familiar, but now revised, V6 TDI engine. The engine retains the double-flow VTG mono turbocharger, 120-degree cylinder bank angle concept that allows the exhaust gas side of the turbocharger to be located within the V angle. Detail changes of the engine include a lighter turbocharger, whilst individual components have been relocated within the engine bay, to allow the more radical aerodynamic package to be realised.
“We’re now using the basic engine concept for the sixth consecutive year. This shows how sound the basic idea still is,” said Ulrich Baretzky. “Due to efficiency increases, we partially compensate for the lower amount of fuel.”
Perhaps the biggest revision to the R18’s powertrain is the switch from flywheel energy storage, to a lithium-ion accumulator. The batteries are located within the main safety cell of the car, within a separated section. The energy stored by the system is generated by an MGU (Motor Generator Unit) operating on the front axle. A low-temperature cooling circuit, which is separate from the engine cooling system, cools the battery cells, MGU, and power electronics. From the 2016 season on, the FIA and ACO have announced a track-specific limitation to be imposed on power output in addition to the previous energy classes. Although the MGU may recuperate any desired amount of energy, it may now only supply 300 kW (408 hp) in the race at Le Mans. Audi has designed its MGU for an output of more than 350 kW (476
The new monocoque chassis consists of a high-strength CFRP structure with an aluminium honeycomb core and Zylon layers integrated into the cockpit walls for additional protection. A CFRP structure at the transmission absorbs impact energy in the case of a rear end collision. With the bodywork fitted, the car is on the maximum length permitted in the championship of 4,650mm.
Audi is keen to highlight the technical advances that its LMP1 program has achieved. The current V6 TDI consumes 32.4 percent less fuel than the first generation did in 2011. This progress is even more substantial in a comparison with the original year of 2006. Back then, Audi used TDI technology for the first time. Today, the R18 with the current engine uses 46.4 percent less fuel at Le Mans. Still, it achieves lap times that are ten to 15 seconds better than a decade ago.