Building significantly upon the work it started ahead of Geneva 2017, Infiniti has revealed the latest iteration of its Project Black S sports coupe. Even more high-tech than before, the new prototype employs technology trickled down from the Renault Sport Formula One Team. A combination of twin-turbo V6, 3 electric motor-generators and advanced motorsport-grade energy recovery give the Project S a hybrid system quite unlike anything else on the road, allowing it to hoard energy and release it at will on the street and track.
Created by a global team within the Renault-Nissan-Mitsubishi Alliance, the Project Black S takes performance above and beyond the Q60 Red Sport 400 coupe, upon which it's based. The heavy lifting takes place around the Red Sport's 400-hp VR30 twin-turbo 3.0-liter V6 engine. Instead of simply massaging more output out of the gas engine, or securing an electric motor or two to the axles, Infiniti surrounds the already-powerful V6 with F1-based energy recovery technologies to push performance benchmarks ever higher.
Infiniti calls the design a "dual-hybrid" and declares it a world first. Derived directly from Formula One, the layout features two types of energy recovery systems, one based on heat and one based on kinetic energy. The kinetic part of the equation is familiar enough – a single motor-generator, the MGU-K (motor generator unit-kinetic), harvests kinetic energy during braking, sending it to the high-rate discharge 4.4-kWh lithium-ion battery pack stored at the rear.
The Black S doesn't stop at brake recovery, adding a single MGU-H (motor generator unit-heat) on each of the two electrically assisted turbochargers. These units transform heat energy from the exhaust gases to usable electricity, sending it to the same lithium-ion battery. So the Project Black S charges the battery during acceleration as well as braking. Infiniti explains that F1 rules limit heat recovery to a single turbocharger, making the Black S unique in its twin-MGU-H layout.
The stored battery power is utilized in two different ways. First, it cuts turbo lag, allowing the engine to deliver its power more quickly and smoothly. Infiniti explains more specifically that it works by "spooling up the turbine blades within both e-turbos more quickly and rapidly increasing the amount of air recirculated back into the engine to boost power."
The hybrid system can also augment the V6 with up to 161 hp of electric motor power directed to the rear axle through a newly designed final drive assembly that incorporates the MGU-K. The Project Black S is now capable of putting out 563 hp, a significant 41 percent boost from the 400 hp of the Q60 Red Sport 400.
Out on the road, the dual-hybrid powertrain gives the Project Black S performance unlike any Infiniti out there. Infiniti says it's capable of running 0 to 62 mph (100 km/h) in under four seconds, helped by the low-down torque of the MGU-K and the helical gear limited-slip differential. Infiniti also says the car's superior power/weight ratio gives it the potential for a higher top speed than the Q60 Red Sport 400, though it doesn't list a specific figure.
Three F1-derived driving modes help the driver find the right blend of performance and energy management for the conditions ahead. "Road" mode involves a relaxed, non-invasive energy recovery that doesn't hinder smooth, seamless roadway commuting, utilizing battery power to help increase the powertrain's overall efficiency and deliver accelerative bursts during common maneuvers like highway entry and overtaking.
"Quali" mode cranks it up full blast, releasing large amounts of energy throughout the ride to help in all-out performance. It assists in maximum acceleration and keeps speed building during long straightaways. To help prevent the battery from depleting, it increases energy recovery efforts during heavy braking through corners, in turn using that energy to help the car exit the corner more quickly.
"Race" mode is more a mid-level mode designed to stretch available energy out while advancing overall lap performance. Infiniti says it most closely resembles the mode utilized by the Renault Sport F1 Team. Based upon a mathematical formula, energy is effectively deployed when improved acceleration can cut lap time but reserved during stretches when the advantages of boosted output are lesser. Real-world race mode operation varies according to track layout.
The dual-hybrid powertrain is the highlight and beating heart of Infiniti's ongoing Project Black S work, but it's by no means the only piece of the puzzle. Infiniti and Renault Sport collaborated closely on the car's aerodynamics, using computational fluid dynamics software. The team has stepped the aero kit up from the 2017 Geneva show car, ensuring effective powertrain cooling and added downforce.
The carbon fiber-finished rear wing is the most visible part of the new aero package and was selected from a number of different iterations that the team worked up. Infiniti admits that further change is possible, but the current wing was inspired by the Renault Sport's Monza wing to deliver a careful balance of improved cornering traction and high-speed stability.
Other aerodynamic additions include a front splitter, enlarged air intakes, hood vents, front aero blades, rear aero foils and a rear diffuser.
Infiniti has replaced major body panels – the hood, roof, trunk lid and fenders – with new aero-optimized carbon fiber panels, saving significant weight over the production steel panels. In fact, despite adding roughly 441 lb (200 kg) worth of dual-hybrid powertrain and cooling hardware, Infiniti keeps weight down to 3,915 lb (1,776 kg) – just 53 lb (24 kg) more than the production Q60 Red Sport 400.
Other weight savings come from the removal of the rear seats to accommodate the lithium-ion battery pack, swap-in of carbon fiber front seat shells and trim, and addition of by-wire carbon-ceramic braking. Through all its reworked components and redistributed weight, the Project Black S gains a near-perfect 50:50 front-rear weight distribution (Red Sport - 58:42).
In addition to the new brake-by-wire system, the Project Black S has drive-by-wire acceleration and gear shifts and steer-by-wire Direct Adaptive Steering. It's the first Infiniti to offer this complete by-wire set-up.
The Project Black S is still a work in progress and Infiniti intends to conduct real-world track testing throughout 2019. The company hints at the possibility of a production variant, saying it sees room for a model level above the Red Sport 400, offering maximum power and performance, an uprated suspension and unique design elements. The technologies tested on the Black S could also find their way to Infiniti's expanding lineup of electrified models – by 2021, it plans for every new model to incorporate electrified powertrain technology.
Even more potentially wide-reaching, Infiniti's work with Renault Sport Formula One is laying the way for more rapid prototyping and production car development. Infiniti engineers are learning from the Renault Sport team's experience in developing complete cars in less than a year and making rapid, on-the-fly changes as needed. In fact, Infiniti says that the 18 months it's taken to build the Project Black S to its current state makes it the fastest-developed vehicle in company history. It believes that it can apply some of its learnings from the project toward cutting the time it takes to bring production cars to market.
The Project Black S prototype was revealed just ahead of the start of the 2018 Paris Motor Show, which opens up to the press on Tuesday. We'll have more coverage of the show throughout the week.
Source: Infiniti