ENGINEERING
Infiniti’s Project Black S prototype is the first road car to include the full technological tricks of an F1 hybrid powertrain. F1 Racing joined Nico Hülkenberg for its first flat-out test
F1 hybrid tech on the road, with Nico Hülkenberg and Infiniti
“Do you hear that?” Nico Hülkenberg poses the question almost rhetorically as he applies pedal to metal and zaps the Infiniti Project Black S prototype out of the Salzburgring pitlane. ‘That’ could be any number of sound inputs: we’re in Mozart country, after all, and a stone’s throw from where Julie Andrews cavorted in the grass while proclaiming the hills to be alive with the sound of music.
Today that music is provided by a 400bhp V6 gleefully accepting a 160bhp kick through an electric motor generator unit mounted to the Infiniti’s rear axle. The electrical skreeee is the noise Hülkenberg is drawing F1 Racing’s attention to: the piercing hum of an F1-derived MGU-K doing its thing.
“Sounds just like an F1 MGU-K,” Nico cackles. “Right, let’s see if we can get up to 200kmh on the pit straight…”
Rewind: when Formula 1 embraced electrified hybrid powertrains nearly six years ago, it did so with the conviction that only by remaining ‘road-relevant’ could it survive and thrive. Had F1 stubbornly remained allied to big, thirsty engines increasingly divorced from the reality of the everyday motorist, the road car manufacturers it relied upon would quickly depart into the ether, as they had done many times in the past. The grand vision was for Formula 1 to act as an incubator for exciting and transformative new technologies, such as e-turbos, that would soon trickle down to showroom product.
Back in the present, that still hasn’t happened yet.
The vehicle F1 Racing has flown to Austria to witness, Infiniti’s Project
Black S, is the only road car to offer a fully
F1-inspired powertrain, from a pair of MGU-H e-turbos to an MGU-K and its associated brakeby-wire system. And it’s still a prototype, albeit a working one based on Infiniti’s Q60 Red
Sport coupé. Until now the powertrain has only delivered its full hybrid punch on the dyno;
Hülkenberg is the first driver to be given carte blanche to turn it up to 11, as it were, on track, with
Renault F1 team principal
Cyril Abiteboul also in attendance.
The Salzburgring isn’t a long circuit – Nico reckons it’s a 50-second lap in a Formula 3 car – but it’s fast and flowing, and not blessed with Tilke-spec run-off. For the purposes of
THE GRAND VISION WAS FOR F1 TO ACT AS AN INCUBATOR FOR EXCITING AND TRANSFORMATIVE TECHNOLOGIES THAT WOULD TRICKLE DOWN TO SHOWROOM PRODUCTS
“YOU CAN TELL IT’S THE SAME FAMILY OF HYBRID TECHNOLOGY. AND ESPECIALLY I FEEL IT WHEN I SWITCH THROUGH THE DIFFERENT ENERGY MODES – MAXIMUM DEPLOYMENT, MAXIMUM CHARGE, SUSTAINABLE OUTPUT. YOU FEEL THE DIFFERENCE IN POWER OUTPUTS YOU GET, OR, WHEN YOU CHARGE, HOW MUCH IT’S ACTUALLY RECOUPING – THAT HANDBRAKE FEELING…” NICO HÜLKENBERG
this test there’s a temporary chicane demarcated by cones in the middle of the back ‘straight’, the better to prevent us from joining the sheep grazing in the pasture beyond the Ostschleife, a quick right-hander that bleeds into the tighter Fahrerlagerkurve at the end of the lap. The shorter pit straight is a surer bet for our unofficial speed record, but despite a kerb-hopping, flat-out exit from the preceding corner, the speedometer peaks a couple of millimetres away from the 200 mark as Nico hits the anchors for the chicane.
“Bah! Well, it’s a work in progress,” he says. “What’s our state of charge?”
For now, a tablet computer is doing the job that one day might be fulfilled by the car’s onboard systems: on the screen a simple graphic representation of the Infiniti’s four wheels and powertrain illustrates harvesting and deployment, a constantly shifting map of lines, arrows and colours. State of charge is 28%, down a fraction from the start of our ‘push’ lap. As Nico dials down the pace a little – and tweaks one of the dials on the central console – the figure creeps up past 30% again, allied to the peculiar feeling that some invisible force is occasionally tugging gently on the handbrake. Is this how powertrain management changes from lap to lap in a current F1 car?
“It is true, it is comparable [to an F1 powertrain],” reflects Nico after we return to the pits and leave the car to cool down. “You can tell it’s the same family of hybrid technology. You recognise the soundbites you hear in an F1 car, and especially I feel it when I switch through the different energy modes – maximum deployment, maximum charge, sustainable output. You feel the difference in power outputs you get, or, when you charge, how much it’s actually recouping – that handbrake feeling...”
The Project Black S began as a concept car, agreed over “dinner and a handshake” between Infiniti’s motorsport chief Tommaso Volpe and Nissan Europe’s head of design, Mat Weaver, in December 2016. Infiniti, part of the Renaultnissan Alliance, had recently transitioned from being a Red Bull sponsor to becoming a technical partner of the reborn Renault F1 team, helping to develop the F1 outfit’s hybrid systems. Weaver’s group had just three months to get the first Project Black S design study ready to be the company’s centrepiece at the Geneva Show – but the really difficult bit came later, once the board greenlit a working prototype.
“At the time, we didn’t really realise how complicated the journey was going to be to arrive at this point, where we finally have the running prototype,” says Volpe. “At Infiniti we started to work on the hybrid technology in F1 only from 2016, so the decision [to build a working Project Black S] came in 2017 and it took time to actually deliver it. The technology is very sophisticated, and very intrusive into the space of a normal car. This is the first example of this technology being applied to a homologated existing vehicle - one that didn’t even have the normal hybrid technology.
“So the challenges start there – where do you actually put three additional motors? You have two MGU-HS and one MGU-K, so three motors, not two like in F1, as well as the batteries and inverters, so the problem is to find a place to fit all these parts. The MGU-H has to be connected to the turbo system, but then the car is very busy at the front, so we decided to put the MGU-K at the rear. The car is rear-wheel drive so it makes sense to have the MGU-K there, but we mounted it to the differential because we didn’t want to add the extra torque to the propshaft and have to change the gearbox as a consequence.
“All the decisions came one after the other and each presented all sorts of challenges in terms of weight and engineering solutions. To accommodate the MGU-K we had to cut into the body of the car, so then we had to make it stiff again, adding metal around it. Then we had the issue of where to put the batteries and the inverters, so we decided to get rid of the rear seats. And of course, keeping all these elements cool is a big issue. If you compare this car with the normal Q60 it has many more air intakes.”
The detailing of the Project Black S has changed during its journey from design concept to working prototype, based largely on the cooling demands of the powertrain. Renault F1’s Enstone and Viry-chatillon facilities have been intimately involved, not only in the finessing of the hybrid components but also in supplying aerodynamic expertise. Naoki Tokunaga, deputy technical director of the F1 team to James Allison during Enstone’s last period under Renault ownership, has overseen the architecture and integration of the hybrid systems.
While the Q60 donor car has a turbocharged V6 powertrain, the internal combustion engine has little in common with an F1 car’s, apart from the number of cylinders. Since it’s a twin-turbo design there was no option to run an F1-style system in which the blower is split across either end of the engine block with the shaft and MGU-H running within the ‘vee’. That also meant two MGU-HS – arguably the most troublesome element of an F1 powertrain in development terms – rather than one. It’s also been a challenge to integrate the operations of the hybrid system and the brake-by-wire with the gearbox, which is an off-theshelf unit with its own proprietary control electronics.
“Apart from the power delivery,” says Volpe, “which is the first objective because you want to have a more performing car, the other thing we wanted to replicate from the F1 experience is the complexity and sophistication of the system in the way you can manage the energy.”
The vision for the driving modes is to offer separate power management strategies: a ‘street’ setting that offers a sustainable power boost for normal use, a ‘race’ setting that delivers extra power over a shorter duration – five or six laps in the context of track use – and ‘quali’ mode that goes all-in on power for a single lap. Two further modes prioritise cooling and recharging, barely tapping into the 160bhp of extra boost available from the hybrid system.
The outer shell of the Black S is similar to the design study but very different in detail. To cope with the cooling demands of the MGU-K, the exhausts have been relocated from the centre to the outer edges of the rear valance; an additional radiator above the diffuser outputs directly into a low-pressure zone behind the car.
“Within the [Renault-nissan] Alliance this is known as a ‘square vee’ project, which means completely from scratch from the platform up,” says Weaver. “So, knowing it [the platform] was the Q60 Red S, we went from the beginning and sketched as if it were a concept. We wanted to push the identity as far as we could. And this was before we started to develop with the guys at Enstone, incorporating their
feedback on aero performance and all these things.”
CFD analysis at Enstone enabled Infiniti to improve the cooling efficiency of the bonnet ‘nostrils’, initially included just as a styling feature, by 10%. It also informed the final look of the rear spoiler, the first iteration of which was based on a single plane of a Monza-spec F1 wing.
“The vents are in a low-pressure zone so it pulls the heat out from under the hood,” says Weaver. “Obviously, we have these big turbo units underneath so there’s a lot of convection. We roughly had them in the right place – we were thinking we would be cooling from behind the radiator core, but actually we moved them back. They sit in one of the few places where you can see down into the engine well, towards the MGU-KS, so they became really functional.
“We had a Monza [rear wing] chord from the guys at Renault Sport F1, a low-drag one, and we put it on, but when it went to CFD testing… basically the car would have been driving just on its two rear wheels, there was so much downforce. We had to change the angle of attack, relax it off quite a bit.”
Once the rough edges have been polished away, the Project Black S might be offered to a wider audience to drive – F1 Racing has already thrown its hat into the ring – but for now it’s a technology exercise . Nevertheless, if F1 technology is to trickle down into the road car world, that trickle must start somewhere.
“It’s an important milestone in quite an important project,” says Abiteboul. “Bringing F1 technology to the road for the first time. It’s a project that will see also the realisation of the decision made by the sport to bring in new power unit regulations in 2014 – being more roadrelevant, more fuel-efficient, to make it real, not just for professional drivers but for you, me, anyone.”
“IT’S A PROJECT THAT WILL SEE THE REALISATION OF THE DECISION MADE BY THE SPORT TO BRING IN NEW POWER UNIT REGULATIONS IN 2014 – BEING MORE ROAD-RELEVANT, MORE FUEL-EFFICIENT, TO MAKE IT REAL, NOT JUST FOR PROFESSIONAL DRIVERS BUT FOR YOU, ME, ANYONE” CYRIL ABITEBOUL