McLaren sets hyperbolic goals for the 720S
There’s always a whiff of hyperbole around the launch of a new car. It’s understandable, of course: Even if the engineers, designers, marketing mavens, and PR flacks knew their shiny new automobile was in some way less than perfect, they’d never admit it—especially to automotive journalists.
But the buzz among those around the 2018 McLaren 720S is different. “Phenomenal.” “Blisteringly quick.” “Extremely fast.” These are all sound bites from informal conversations with the team that developed the 720S. “Wait until you drive it,” they say. “You’ll have to recalibrate your idea of road car performance.”
Color us intrigued.
Some background: The clumsily named MP4-12C, McLaren’s first road car aside from the limited-production F1 (only 106 made in total between 1992 and 1998), has evolved into two supercar families since its 2011 launch. The Sports Series is composed of the lower-powered and more affordable 540C, 570S, and 570GT models, while the Super Series is made up of the 650S and the edgier 675LT, each available in Coupe or Spider form. The 720S replaces the 650S, and it kick-starts the second-generation Super Series lineup.
The 720S uses a 4.0-liter twin turbo V-8 based on the 650S’ V-8 architecture, but 41 percent of the engine’s parts are new, earning it a new model designation: M840T. Changes include a longer stroke, which means a new crank and pistons, plus new cylinder heads, new exhausts, and a comprehensively redesigned intake system, which features larger, low-inertia twin-scroll turbochargers.
Given McLaren’s naming policy, there are no prizes for guessing the new engine produces 720 ps per the European measurement—that’s 710 American horses. There’s been a healthy bump in peak torque, too, up from 500 lb-ft to 568 lb-ft. Those numbers contribute to a claimed 0-60-mph time of less than 2.9 seconds—impressive for a two-wheel-drive car—and a claimed top speed of 212 mph (341 km/h). McLaren also says the 720S will run the quarter mile in 10.3 seconds.
The engine drives the rear wheels through a Graziano seven-speed dual-clutch transmission, now with shift software developed completely in-house at McLaren. The computer-controlled suspension is philosophically similar to that of the 650S, but the hardware is new, adding different geometry and dropping 35 pounds (16 kg). More important, the suspension control software is also new, and it’s much more powerful thanks to 21 sensors—12 more than used on the 650S—that monitor everything from wheel movements to steering wheel angle to yaw motions.
The 720S is built around a brand-new one-piece carbon-fiber tub with an integrated roof that’s similar in concept to the MonoCage structure used in the P1 hypercar. MonoCage II gives the 720S a different profile, but what everyone will notice first about the car is the absence of the side scoops that have been a visual signature of all McLarens since the 12C.
“It would have been easy to just keep evolving the design,” says Mark Vinnels, executive director of program development at McLaren Automotive. “But we decided we wanted a clean body side to transform the look of the car.”
Doing that while keeping the twin-turbo V-8 cooled and fed with air was easier said than done, however. McLaren’s solution was to direct air over the top of the front fenders of the 720S and into two deep channels on either side of the cockpit. These lead to radiators mounted ahead of the rear wheels then sweep around the C-pillars to extract the air the radiators have heated. Although driven by function, the resulting form is also visually dramatic. The fenders seem to be peeling away from the cockpit and engine compartment as if the 720S has been caught metamorphosing into a McLaren F1 racer.
“I remember thinking: Are we brave enough to do this?” chief designer Rob Melville says. “Traditionally a supercar is really nipped in behind the front wheels; it has that traditional Coke-bottle shape. In this one, if you look at the plan view, it’s actually quite square.”
Melville describes the line that runs off the hood and through the door as “the trickiest I’ve ever done on a car.” What’s more, because the cooling air channel carves deeply through the door surface as it meets the greenhouse, each door has a fantastically sculptural cross section. “The door was pretty challenging,” Vinnels says. “We had no idea how we were going to make a door this complex.”
Instead of traditional faired-in headlights, the front end of the 720S features what are, in effect, two large vents with the headlights mounted vertically within them. Nicknamed eye sockets by Melville, they funnel air through two smaller radiators mounted just ahead of the front wheels. The hot air from these radiators then exits ahead of the wheels and is directed along the sides of the car. Another advantage of the design: compact headlights that are brighter and have better spread than those of most other supercars, Melville says.
Of course, what everyone wants to know is how the 720S drives. According to the only data points McLaren has released so far, it has 69 more horses and 68 more lb-ft than the 650S, weighs 205 pounds (93 kg) less, and generates 50 percent more downforce and 6 percent more mechanical grip.
One man who knows what those numbers mean on the track is long-time McLaren test and development driver Chris Goodwin. “It’s quicker than expected,” he says. What the numbers don’t reveal, he adds, is the precision of the car’s throttle response and its outstanding cornering ability. “You’ve got a car that feels as nimble and has the same sort of balance you’re used to in a McLaren, but you can be a gear higher through some corners. It has so much more cornering performance. The driving experience is a massive leap.”
Supcar Science: Tech tricks of the McLaren 720S
Compact intake system
New twin-scroll turbochargers feature lightweight titanium and aluminum alloy turbines, which are connected to the compact plenum via a very short intake path. Adopting low-inertia turbines and minimizing the air volume between the turbo housing and the intake valve help improve throttle response, aided by the engine calibration strategy that keeps the turbochargers spinning as much as possible by using actively controlled wastegates. The compact intake system has also reduced overall engine height by 4.5 inches, lowering the center of gravity, improving rearward visibility, and increasing luggage space.
The carbon tub in the existing McLaren Sport Series and Super Series cars is literally a tub—to which are attached the front and rear aluminum subframes and the aluminum roof structures. However, the one-piece central tub in the 720S also includes the roof and door apertures. It saves 40 pounds (18 kg) compared with the 650S tub/roof and allows the use of dihedral doors with large cutouts for improved cabin entry and exit. The light, stiff, and strong carbon structure has also allowed McLaren engineers to use thinner A- and C-pillars, creating a cockpit with truly impressive all-around visibility for a mid-engine supercar.
Because of the construction methods needed to deliver their form, the doors are heavier than conventional units. But because the doors make the cooling system 15 percent more efficient, the McLaren engineers compensated by making the radiators smaller and lighter. This allowed them to move the engine intake air boxes right to the rear corners of the car—air enters via two ducts on the upper surface of the fenders. Thus, the air boxes are structural elements that support the fenders, saving just over 3 pounds (1.4 kg) compared with the design used in the 650S.
The full-width wing across the rear of the 720S can be used to increase downforce and as an airbrake. In the downforce position the wing develops 30 percent more downforce than the version on the 650S. A downwash effect directs the airflow into the intake ducts at the corners of the rear fenders and into the engine to further improve performance. The wing is fully deployed as an airbrake within a half second of the driver touching the brake pedal, shifting the balance of the car rearward to improve braking grip at the rear wheels.
Optimal control theory
The Proactive Chassis Control II suspension system uses what McLaren calls Optimal Control Theory, an algorithm that calculates—in real time—the optimal vehicle responses to driver inputs. Developed from a University of Oxford research project started in 2010, it sounds a lot like Ferrari’s brilliant Side Slip Control system, something with which 720S chief engineer Emilio Scervo has more than passing familiarity. Scervo, who joined McLaren in January 2014 just as work started on the 720S development program, previously worked at Ferrari as part of the team that developed the 458 Italia, and was chief engineer on the 458 Spider and 458 Scuderia.
The meteoric rise of McLaren: 15 new cars by 2022
Although McLaren traces its heritage back to the 1963 foundation of New Zealand racer Bruce McLaren’s eponymous Formula 1 team and in 1992 produced the seminal 240-mph (386 km/h) McLaren F1 hypercar in boutique numbers, the road car business, McLaren Automotive, has only been around since 2010.
“F1 teams inevitably come and go,” McLaren boss Ron Dennis said at the time. “Making road cars is the future. There may be an economic situation in the future where McLaren Automotive supports the Formula 1 team.”
Indeed. Although the F1 team has struggled to perform in recent years—and lost major sponsors—McLaren Automotive has seen sales grow from a few hundred cars in 2011 to more than 1,600 in 2015 and more than 3,200 last year.
McLaren Automotive says it is self-funding, has been consistently profitable since 2013, and is currently investing 25 to 30 percent of its revenue in R & D. The engineering team has grown from 40 people to 450 since 2010.
With a new chassis, new suspension, new body design, new interior, and significant changes to the powertrain, the 720S is the first of 15 new McLarens planned by 2022 as part of the company’s massive billion-dollar-plus Track22 program. Half the cars will be hybrids, with powertrains rumored to be under development with BMW, and one will be an all-electric hypercar.
McLaren’s sales target this year is 4,000 cars, sold through 80 retailers in 30 countries.
|2018 McLaren 720S|
|BASE PRICE||$285,000 (est)|
|VEHICLE LAYOUT||Mid-engine, RWD, 2-pass, 2-door coupe|
|ENGINE||4.0L/710-hp/568-lb-ft twin-turbo DOHC 32-valve V-8|
|TRANSMISSION||7-speed twin-clutch auto|
|CURB WEIGHT (F/R DIST)||2,850 lb (mfr)|
|L x W x H||178.6 x 81.0 x 47.1 in|
|0-60 MPH||2.9 sec (mfr est)|
|EPA CITY/HWY/COMB FUEL ECON||Not yet rated|
|On Sale In U.S.||June 2017|