Hybrid race cars develop technology with production car potential

World Endurance Championship is an incubator for innovative powertrains

Published: September 22, 2016, 7:15 AM
Updated: November 21, 2021, 3:24 PM

Toyota TS050 WEC Race Car

AUSTIN, TX – “Race on Sunday, sell on Monday.” That used to be the mantra when stock car racing was in its heyday with the “Big Three” slugging it out on the track and the showroom with race cars that were very close to “stock”.

Today’s NASCAR race car bears little resemblance to the cars wearing the same names in showrooms. Have you seen any rear-drive, V-8-powered two-door Fusions, Impalas or Camrys on the road recently?

On the track they are all virtually identical other than the stick-on wrap wearing their names and fake lights. While the production versions have four-cylinder or V-6 engines coupled to eight or nine-speed automatic transmissions driving the front wheels, the race cars have a big V-8 coupled to a four-speed manual transmission driving the rear wheels.

It used to be that technologies introduced on race cars found their way into production vehicles. Improvements in aerodynamics, valve trains, brakes and other areas benefitted consumers. But now, if you want to see racing technology that reflects what is happening in the real world, you can forget about NASCAR or Indy cars.

WEC is where the technology is

Formula One now utilizes sophisticated energy recovery systems to supply supplemental power on demand, which may have some remote connection with production cars. But if you want a real glimpse into the future from the race track it’s in the WEC – the World Endurance Championship. Here major manufacturers are pitting their engineering prowess against one another with an amazing array of hybrids!

Like the ones you can buy at the dealer down they road, these have a fossil fuel-burning engine paired with electric motors. But, they are diametrically different from the hybrids on your block, known as frugal fuel sippers with nary a sign of high performance.

The vehicles fielded in the WEC by Audi, Porsche and Toyota are massively powerful and fast. Each manufacturer admits to a 900-1000 horsepower output, but insiders say it is more than that with equal amounts of power from the engine and electric motors.

These are blisteringly fast race cars, especially out of the corners where the massive amounts of torque from electric motors can be applied through all four tires, thanks to sophisticated all-wheel drive systems. These 875-kilo rockets easily reach speeds in excess of 400 km/hr. and get there in no time at all.

Regulations encourage innovation

The WEC schedule includes races around the world, from Europe and Asia to Mexico and the United States. But it is best known for the 24 Hours of Le Mans.

Regulations established for Le Mans aren’t based just on traditional restrictions such as engine displacement. But they do restrict the amount of fuel and electric energy available. Fuel flow is closely monitored and the amount allowed per lap varies from track to track. That quantity has been gradually reduced in order to reduce top speed, by 10% for 2016, for example. But competition and innovation has resulted in engineers finding ways to achieve more power and efficiency.

The three manufacturers participating in the top WEC class – LMP1 (Le Mans Prototype1) have each taken a different approach in dealing with the regulations. All use a conventional fuel-burning engine and KERS (Kinetic Energy Recovery System) but the type of engine and methods of capturing and releasing energy differ.

KERS converts energy, present in the otherwise wasted heat created by the friction of braking systems, into electricity that is stored in in batteries or ultracapacitors, to be released on demand. Mechanical systems use the captured energy to turn a flywheel which is connected to the drive wheels on demand for that extra boost of power. 

Audi vs Porsche vs Toyota

Audi R18 race car uses a 120-degree 3.7-litre V-6 diesel engine with a single turbocharger paired with a single front axle KERS system (developed by Williams for Formula One use) for energy retrieval. The KERS system is a flywheel connected to the front wheels. The diesel engine produces 558-horsepower and the motor-generator 496-horsepower.

Porsches’ 919-hybrid uses 2.0-litre, gasoline-fueled, turbocharged V-4 engine and a mechanical (flywheel) KERS system similar to that of sister company Audi. But, in addition to energy from brake heat, the Porsche KERS system captures energy from the excess exhaust gases normally released by the wastegate.

The Toyota TS050 hybrid uses a 2.4-litre, twin-turbo, 90-degree, gasoline-powered V-6 engine paired with a twin-axle KERS and high-power lithium-ion battery storage.

We have already become used to hybrid passenger vehicles with internal combustion engines, brake energy recovery systems and electric motors that are known for their fuel-sipping habits. But several exotic cars are now using hybrid systems to increase their power output and Volvo is already demonstrating a car with a KERS system.

So how long can it be before we see high-performance hybrids in more mundane production cars using lessons learned in the WEC? Bring it on, we say!