Honda’s new Acura NSX is the first to marry a V-6 engine to three electric motors for high-speed steering
One. Two. Whoosh. By the time I count to three, the Acura NSX’s automated launch control leaps from a standstill to 60 miles per hour. But there’s not a trace of wheel spin and smoking rubber, the usual hallmarks of a neck-snapping drag-strip run here at the track in Thermal, Calif. Oh, there is drama, only it’s largely confined to what’s happening under the Acura’s swoopy skin.
This Acura is a plug-in hybrid, part of an electron-pumping vanguard that’s changing the very definition of a performance car. From showrooms to race paddocks, the clock is ticking for fuel-slurping gasoline engines. Battery-boosted cars, whether hybrid or full electric, are rushing to fill the gap. In our highly regulated future, these may be the only kinds of sports cars you’ll be able to buy, and the trippy journey to such a world seems to be taking place at warp speed.
Hunkered Down: The new Acura NSX has a twin-turbo, 500-horsepower V-6 engine, which is mounted longitudinally in the midsection for optimal handling. A 75-degree angle between the cylinder banks lets the engine hunker down, giving it the lowest center of gravity in its class. Photo: Acura
Back in 1990, the original Acura NSX challenged every notion of what a supercar was supposed to be. Coming from Honda, the manufacturer of the Acura luxury brand and a company known for safe, affordable, and ultrareliable cars, the NSX wedded those practical virtues to a gorgeous lightweight body designed by Italy’s Pininfarina. Smack at its center rested a modest 3-liter V-6, capable of 200 kilowatts (270 horsepower). Packing more lightweight aluminum than anything from Ferrari, Lamborghini, or Porsche, the Acura defied expectations again with a shocking US $60,000 price, a fraction the cost of its highfalutin rivals. In a final coup, Brazilian Formula One superstar Ayrton Senna, then driving for McLaren-Honda, helped tune the NSX’s suspension and performance prior to its release.
Ferrari and Co. were instantly forced out of their complacency on technology and quality alike. The NSX topped the Ferrari 348, and most every other competitor, in handling and daily drivability.
So when Honda found itself developing a reborn NSX in 2011, the new car had massive shoes to fill. Oddly, Honda’s engineers originally planned to power their new roadster with a prosaic V-6 derived from an Odyssey minivan. No wonder that project was aborted midstream. To deserve the storied name, any Son of NSX would have to be an “everyday supercar” while again moving the needle on technology. Ted Klaus, chosen to head up the NSX’s global R&D team—which is now run out of Ohio, rather than Japan—knew that electricity was the answer, not just to power the car but to perform handling magic as well.
“We had been working for years to come up with drive force that could help turn the car right and left,” Klaus recalls. “We asked ourselves: What if we could marry emerging hybrid e-drive technology with yaw-control tech [that is, steering]? Would it be possible?”
The answer was yes. But the tight-knit NSX team was facing three more years—and an increasingly skeptical media and fan base—to create that ambitious design from scratch: a hybrid supercar that converts electricity into mechanical commands, not just for explosive, efficient propulsion and regenerative braking but also to steer and stabilize the car.
As it happens, Porsche was developing an all-wheel-drive hybrid with similar characteristics, the 918 Spyder; it would arrive priced at a mind-boggling $845,000. The 2017 NSX that I’m testing near Palm Springs costs $157,800.
And unlike the Porsche, which has just one electric motor to power both front wheels, the Acura has two electric tricks up its sleeves: the so-called Twin Motor Unit. This dizzyingly complex electric duo, mediated through a planetary gear set, cranks out up to 27 kW (36 hp) and 73 newton meters (54 foot-pounds) of torque to either wheel, divvying it up as needed. This is true torque vectoring, able to independently speed up or slow down either wheel, helping the Acura dive into turns and dig out the other side. Discreetly nestled behind pilot and passenger, the roughly 1-kilowatt-hour lithium-ion battery is designed to rapidly charge and discharge for generous squirts of performance. A larger battery might have contributed more all-electric driving range, but it would have come at the expense of weight and ultimate performance.
The instant the driver rotates the steering wheel, sensors sample the car’s controls, and then software processes the data in just 10 to 20 milliseconds. The time it takes the electrical system to convert that input into steering response, Klaus says, is on the order of 50 ms. Yes, that’s fast. Front-axle motors deliver their full monty of instantaneous torque at every possible engine speed between 0 and 2,000 rpm; 2,000 rpm is the point at which the gas engine rouses itself to take over the majority of propulsion. The electric motors can still help propel the car at up to 200 kilometers per hour (124 miles per hour) and assist in turning right up to the car’s 300-km/h top speed.
To provide shove at the rear wheels, a 3.5-L racing V-6 shares nary a bolt with any production Honda engine ever built before. A 75-degree angle between its cylinder banks lowers the center of gravity, in unique contrast to the industry’s typical 60-degree V-6s. And it churns up 373 kW (500 hp) and 550 N∙m (406 foot-pounds) of torque. A third electric traction motor, with 35 kW and 148 N∙m of torque, sandwiches between the engine’s crankshaft and nine-speed, dual-clutch automated gearbox. The motors even help smooth gear changes, adding power as engine speeds fall during shifts.
Add it up and the NSX sends 427 kW (573 hp) and 633 N∙m (476 ft.-lbs.) to the wheels, on par with gas-only supercars like the Audi R8 V-10 that have more cylinders and consume much more fuel.
So how does it drive? To find out, I chased Indy driver Graham Rahal around the Thermal Club’s snaking road course [PDF]. This was definitely the time to dial the NSX up from its Quiet setting, the Sunday-church mode that prioritizes electric propulsion and highlights those smooth Honda manners. I moved through Sport Plus to Track mode, which transformed the car into the howling, road-clawing beast you’d expect at this price. The car’s driver-selectable performance modes, four in all, can vary engine sound by as much as 25 decibels, with natural frequencies pumped into the cabin via tubes behind passengers’ heads.
Right Stuff: Ted Klaus, head of NSX development, takes a whirl in his baby. Photo: Acura
This yin-yang quality pervades the Acura. You could argue that it tries too hard to be an everyday Honda, to disguise the seriously heroic stuff under its skin. Since when do supercar owners, the flamboyant types who drop six figures on a howling Lamborghini, prefer to fly below the radar?
Indeed, my first experience here in the Honda has me questioning its supercar bona fides. There’s plenty of tire grip, but the steering feels a bit robotic. The turbos emit a discreet whoosh, but the V-6 itself sounds meek and wholly unthreatening. And while the speedometer says we’re making good time, the Acura feels sneaky fast, not freaky fast.
Whether the subject is street cars or the pinnacle of motor sports in Formula One—and its offshoot, the all-electric Formula E series—the purists’ complaints have been as loud as the cars are quiet: Electricity will silence the shriek and dull the visceral sensations that have thrilled drivers and spectators for more than a century.
“I would say that’s a hot topic, the emotional attributes of an electric car,” Klaus acknowledges. “I like the idea that electric propulsion can stir your soul, without constantly shaking you up.”
And even professional racers, he argues, don’t like a car that’s always on the edge, requiring constant correction and mental and physical strain. “That kind of car uses so much of your human bandwidth that you can’t extract maximum performance,” he says. “We’ve electrified a supercar that gives you a wide range of emotional experiences, from quiet cruising to unleashing the beast at the track.”
Cars like the Acura may never wail like a V-10 Lamborghini, at least not without the artificially synthesized sound of cars like the BMW i8, the autosport equivalent to lip-synching. But nor does the Acura slurp premium unleaded as shamelessly as a ’60s muscle car. The U.S. Environmental Protection Agency credits the NSX with 11.2 liters per 100 kilometers (21 miles per gallon), commendable for a supercar that can hang with a Ferrari 458, Lamborghini Huracán, or Porsche 911 Turbo.
Clean-sheet Design: Honda’s Ohio Performance Manufacturing Center is all new, like the NSX it makes. Ablation casting uses water to blast sand from molds, quickly cooling the molten aluminum for a stronger microstructure and superior crash performance. Eight robots apply 860 welds to the aluminum space frame. Wireless torque wrenches record tension settings for every bolt. Photo: Acura
This being Honda, the NSX team set itself another lofty goal, creating what they believe is the world’s safest supercar. Klaus and his team say the NSX is measurably more crashworthy than its rivals. Maybe that’s not sexy, but it might save a driver’s life in a car designed for pushing the envelope.
The team also developed numerous fail-safes to ensure consistent, trustworthy performance.
“It took a couple of years to harden the system to our high reliability standards, so that if someone puts in an unusual or unskilled input, the vehicle’s safety performance is in line with an Accord or Civic,” says Klaus. “At up to 300 km/h or pulling over 1 g (in handling force), we had to make it accelerate, brake, and turn according to the driver’s desires, but ensure that nothing uncontrolled would happen to a driver or those around them in case of an electrical or mechanical failure.”
Despite all the integrated systems and all the electronic oversight, the Acura must still feel like a natural, involving sports car. The bravura brake-force simulator is a shining example: All supercars go, but the NSX is special for how it stops.
The problem is that any hybrid car that wants to save fuel must brake regeneratively: Those electric motors must also be able to function as generators during braking, turning kinetic energy into electricity that is shunted to the battery for reuse. But that tends to give brakes a nonlinear, mashed-potatoes feel.
“We needed a breakthrough in man-machine engineering,” Klaus says. “How much force do drivers want to feel, and how do we link that to deceleration value?”
The answer was a system that simulates natural brake-pedal feel via a separate hydraulic circuit. Pushing the brakes triggers an electric motor that varies the amount of resistance felt in the pedal, but none of that hydraulic fluid is actually stopping the car. Your foot’s commands are actually electronically translated to activate brakes on a separate hydraulic circuit. The result is perhaps the most natural, linear-feeling hybrid brakes yet, whether used around town or at the track.
Automated Automaker: The low-volume factory requires only 100 technicians to assemble, paint, and monitor quality for the NSX. Photo: Acura
“Those brakes felt horrible at the beginning of development,” Klaus says. “There were a lot of sleepless nights on how that system didn’t feel natural.”
Honda’s customary no-stone-unturned approach extended to manufacturing. In Ohio, where Honda built its first American Accord in 1982, the NSX has begun rolling off the line at a showpiece plant called the Performance Manufacturing Center, or PMC.
Clement D’Souza, the engineer who led development of the PMC, said that Honda visited about two dozen other factories, including those at Ferrari, McLaren, and Porsche, to benchmark manufacturing processes, tailoring its approach to that of Formula One teams. On its meticulous, low-volume assembly line, NSX is treated to a dozen patent-pending processes, including the world’s first use of ablation casting in an automobile: Sand molds for parts of the aluminum space frame are ablated, using water to dissolve the binder and blast away sand, which has the virtue of quickly cooling the newly solidified metal. That creates a stronger microstructure, which allows lighter, thinner castings with superior crash absorption. The largely aluminum space-frame chassis, with a carbon-fiber floor and mixed-materials body (mostly aluminum and sheet-molded composite) feels as indomitable as anything in the class. Acura claims the chassis is much more rigid than those of its rivals, with the lowest center of gravity—a boon to handling.
In Anna, Ohio, at Honda’s largest engine plant, technicians hand-assemble the NSX’s novel V-6 and mate it to the gearbox and rear-drive electric motor. Honda will complete only about eight NSX engines per day, but its technology can now trickle down to the company’s other cars. Elements of the NSX’s all-wheel-drive hybrid technology, Klaus notes, are already found in affordable models including the MDX crossover and RLX sedan.
For type A drivers, the effort all comes together with a few toggles of the performance dial. Cranked up to its Track mode on the road course at Thermal Club, the NSX palpably transforms from benign Jekyll to murderous Hyde, bounding into corners and wagging its exotic tail on the way out. That electric umbilical cord is severed and forgotten, and the Acura is suddenly an Italian-baiting supercar but undoubtedly more rock-solid reliable, just like the original NSX.
I depart the track for a run to the town of Idyllwild, then a fantasy two-lane descent from the San Jacinto Mountains. The Acura slingshots from curve to fate-tempting curve. I’m driving as quickly as I dare on public roads, letting those front wheels electrify their way into and out of every corner. The threesome of electric motors fills every power gap in the turbocharged engines, with surges of juice making up for turbo lag and smoothing gear changes. The NSX actually gets to 100 km/h fastest in Sport Plus, the mode in which the computers let the motors suck more battery power than usual, knowing it’ll be instantly recovered via the frequent regeneration inherent to street driving. With such consistent power, and all the piped-in sounds, you’d almost swear a naturally aspirated V-8 was roaring behind your head.
The Acura corners with near-Italian brio, its variable-ratio steering finely weighted, though the steering is not especially good at transmitting information on the road surface into your hands. That’s surely due to the filtering effect of its electric systems. Ultrawide-range magnetic dampers stiffen or soothe the car at all four corners, pancaking the NSX to the road with extra syrup. Maybe this Acura has a heart after all, beneath that sleek aluminum skin and layers of technology.
So what do cars like the NSX mean for the future of performance and, more specifically, for electric propulsion?
Despite giveaway fuel prices in the United States, a sales explosion for SUVs around the world, and an ice-cold market for electric cars not named Tesla, automakers big and small continue to pour resources into hybrids. Companies as different as GM and McLaren are focused on fun-to-drive performance, not just efficiency.
Tesla has something to do with that. In 2008, its Roadster overturned the stereotype of EVs as glorified golf carts. Just as important are new emissions and fuel-economy regulations, which are compelling carmakers to electrify their fleets.
BMW may have blinked, abruptly changing the course of its high-profile i Division: Electric cars are out, autonomous cars are in. For its next all-new EV, the iNext, slated for 2021, BMW is suddenly touting autonomous function as much as its electric power train.
Yet Ferrari has pledged that every new model will be a hybrid, turbocharged, or both. McLaren’s Track 22 project targets 2022 to electrify half its models, including a potential all-electric version of its fearsome P1 hypercar. Porsche has an electric sedan in the works, based on its stunning Mission E concept.
The jury is still out on whether electricity will entirely displace old-school internal combustion in performance cars. But Klaus is convinced that electricity will soon be an unstoppable force. “Electric propulsion has a bright future,“ he says. “There’s no two ways about it.”
This article appears in the October 2016 print issue as “Supercar 2.0.”