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McLaren Artura V6 Engine Produced Using 3D Printed Cores

The brief for the McLaren Artura was even more challenging than its predecessors: to create a series-production High-Performance Hybrid supercar that excels on every level, with performance, engagement and efficiency sharing equal top-billing. The engineering and design team approached the challenge holistically – no single part of the process was undertaken in isolation – with ambitious targets set in every area: weight; performance; driver engagement; efficiency; agility; refinement; quality and usability. Of course, 3D printing had to play a part. McLaren confirmed the use of 3D printed cores in the engine production process, however, it is suspected other parts of the chassis and powertrain were directly printed as well.

Ever since the 12C revolutionized the supercar segment a decade ago, McLaren Automotive has continued to push the boundaries of supercar innovation. The McLaren P1 brought McLaren hybridization to the hypercar sector as long ago as 2012. The Speedtail introduced astonishing new levels of hybrid performance, its 403km/h (250mph) maximum speed making it the fastest-ever McLaren.

McLaren Artura
McLaren Artura

Every target was met – and in most cases, surpassed – heralding the arrival of the Artura as a next-generation McLaren High-Performance Hybrid that introduces a new supercar era.

“The way we design cars at McLaren is different. We use a holistic approach comprising both technical design and studio design, areas that in the automotive industry are often separated and sometimes even compete; McLaren sees these pillars as integrally linked and working towards common goals,” said Dan Parry-Williams, Director of Engineering Design, McLaren Automotive.

3D printed core in the V6 engine

“Our all-new V6 engine is compact, light, powerful and extremely efficient. The dimensions aided packaging of the hybrid system and enabled a lower center of gravity for the Artura, while the 120° vee design allowed us to have a very short and stiff crankshaft, which means the engine can rev all the way to 8,500rpm, delivering the drama and excitement you expect from a McLaren supercar,” said Richard Jackson, Head of Powertrain, McLaren Automotive.

Designed by McLaren engineers to set new standards for smaller capacity V6 turbocharged engines, an all-new 3.0-litre V6 is at the heart of the Artura’s powertrain. Generating 585PS (577bhp) and 585Nm (431lb ft) of torque, the M630 produces more PS per liter than any McLaren engine except for the 4.0-litre V8 of the Elva and McLaren Senna. Lightweight – at just 160kg it weighs 50kg less than a McLaren V8 – and extremely fuel-efficient, its unique wide-angle configuration and compact size enable a High-Performance Hybrid powertrain package that is shorter than McLaren’s V8 engine and seven-speed transmission. That’s all the more impressive given the addition of an eighth gear, as well as the inclusion of McLaren’s first electronically controlled differential.

2,993cc twin-turbocharged V6; 120° v-angle with turbos in ‘hot vee’. Develops 585PS – a specific output approaching 200PS per litre – and torque of 585Nm Light and compact: 50kg lighter and 190mm shorter than McLaren V8 engine
2,993cc twin-turbocharged V6; 120° v-angle with turbos in ‘hot vee’. Develops 585PS – a specific output approaching 200PS per litre – and torque of 585Nm Light and compact: 50kg lighter and 190mm shorter than McLaren V8 engine

Mounted longitudinally and driving the rear wheels, the engine is a 2,993cc dry-sump V6 with an 84.0mm bore and 90.0mm stroke. Valve timing is continuously variable. Peak power of 585PS (577bhp) is produced at 7,500rpm, with the redline at 8,200rpm (8,500rpm intermittent). 585Nm (431lb-ft) of torque is generated from 2250-7000rpm. Gasoline direct injection (GDI) operating at 350bar pressure ensures precise fuelling for increased power and reduced emissions, with one central injector per cylinder, while Gasoline Particulate Filters (GPFs) and catalytic converters ensure all legislative requirements are met.

The engine employs a 120˚ ‘hot vee’ layout. This configuration allows shared crankpins enabling a very short and stiff crankshaft appropriate for high power, high-revving engines. The wider angle brings advantages that include a lower center of gravity and the creation of a cavity within the vee to house the twin turbochargers. This is one of the factors that makes the engine 220mm narrower than McLaren’s twin-turbocharged 4.0-liter V8, its compact nature assured by additional advantages in length and weight.

The ‘hot vee’ configuration additionally optimizes performance and emissions. This enables short, equal-length exhaust runners feeding the turbos, allowing faster spooling with very close-coupled catalysts feeding straight to the rear with minimal pressure drops.

Unusually, the compact mono-scroll turbochargers are symmetrical, removing the performance compromises usually seen in the exhaust and intake systems of twin-turbo vee engines. The system uses ball-bearing technology to reduce friction within the turbo, allowing it to spin up faster. Combined with electronically actuated wastegates that can instantly adjust position regardless of system pressure, turbo-lag and response time are minimized. This – together with the power from the E-motor – gives the Artura extremely rapid response to throttle inputs.

A series of complex heat shields tightly surround the ‘hot vee’ to cool it efficiently. These enclose the engine to stop heat diffusing through the rear of the vehicle, with nozzles fed from the back of the high-temperature radiator (HTR) fans to blow air at high speed between the top of the ‘hot vee’ and the underside of the heat shield. This heated air is funneled out through the powertrain chimney, an opening in the heat shield in the center of the rear deck mesh.

The lightweight engine block, cylinder heads and pistons are all aluminum. The block has directly coated parent bores rather than separate coated liners. This technology allows the engine to be significantly shorter. The cylinder head and block utilize 3D printed cores, a technology more typically used in Formula 1 than road cars, allowing uncompromised precision cooling, for example, a micro-compact 2mm cooling passage between the cylinders.

Another innovation – this time benefitting refinement and packaging – is the location of the chain drive at the rear of the engine. This reduces NVH intrusion into the cabin, as well as torsional vibration. Overall, the new V6 produces very little mechanical noise, either from the engine itself or associated pump and valvetrain sounds. Intake noise has also been optimized for refinement.

The combination of enhanced refinement and instant driver engagement under throttle enables the Artura to fulfill its dual role as a vehicle that can be driven every day in normal urban traffic and an incredibly immersive supercar on road or track.

The advances in refinement have allowed McLaren to tailor a unique exhaust sound when the throttle is depressed. The delta between on- and off-throttle sound is the greatest of any McLaren to date, acknowledging the differing demands of the High-Performance Hybrid powertrain’s driving modes. This has been achieved through a number of routes, including the reduction in length of the exhaust system itself – the exhausts exit straight back from the ‘hot vee’, reducing weight and allowing for the creation of a full-width rear diffuser. The lightweight exhaust system has optimized resonators to enhance the Artura’s harmonic and full-bodied exhaust note.

Super-lightweight engineering

The Artura is the first McLaren to use MCLA, which is designed and produced at McLaren Composites Technology Centre in Sheffield, UKOptimised for High-Performance Hybrid models, MCLA comprises three elements: carbon fibre monocoque, electrical architecture and chassis and suspension structures
Carbon fibre monocoque is safer, stronger and like-for-like lighter than previous McLaren monocoques

“The new McLaren Carbon Lightweight Architecture (MCLA) is quite literally at the core of the super-lightweight engineering philosophy that is inherent throughout the Artura. We developed this all-new, High-Performance Hybrid supercar with all of our learnings from decades of working with advanced composite and other lightweight materials, using world-first processes and techniques to deliver weight savings that offset heavier hybrid powertrains, ensuring greater energy efficiency and maintaining the outstanding agility and dynamic performance our customers expect,” Jamie Corstorphine, Director of Product Strategy, McLaren Automotive.

To achieve the very specific aims of the McLaren Artura program McLaren started right at the core of its new supercar, with a completely new carbon fiber architecture. This had to not only be true to the company’s philosophy of super-lightweight engineering for dynamic and performance reasons but also crucially to offset the extra weight of a hybrid powertrain, as well as being tailored to accommodate the battery pack.

The new architecture – called McLaren Carbon Lightweight Architecture (MCLA) – features three elements: an all-new carbon-fiber monocoque occupant structure, a new chassis with aluminum crash beams and rear subframe, and a first-to-market domain-based ethernet electrical architecture.

Four years in the making, MCLA is the first architecture to be manufactured at the McLaren Composites Technology Centre (MCTC), a new, state-of-the-art facility in the Sheffield region. Flexible in application (but physically incredibly stiff and strong) this scalable platform architecture heralds the beginning of a new era of McLaren supercars.

Carbon fibre monocoque

At the center of the new platform is the carbon fiber monocoque. McLaren pioneered composite technology in Formula 1 racing nearly 40 years ago and first transferred it to the road in the carbon fiber chassis and body of the McLaren F1. When the 12C was unveiled in 2009 it introduced a unique one-piece molded carbon fiber chassis that was 25% stiffer than an equivalent all-metal structure and 25% lighter than a comparable aluminum chassis. McLaren’s revolutionary technologies also allowed carbon fiber monocoques to be productionized in volumes never before achievable.

The McLaren Artura marks another revolutionary leap. No McLaren monocoque, whether designed for the road or race track, has ever had to do more: the carbon fiber structure now additionally provides a safety cell for the battery pack and integrates further crash and load-bearing functionality. Yet it remains incredibly lightweight, weighing just 82kg including the battery compartment, aero surfaces, B-pillars and door-hinge fixings, contributing to the low overall weight of the Artura, despite its 130kg of hybrid components.

At first glance, the MCLA monocoque may appear similar to other McLaren carbon fiber structures, but the geometry of every surface is new, and it is constructed from four new carbon materials, a new resin system and a new structural core material. These new properties accommodate both the platform requirements and new, bespoke mechanized production processes now on stream at MCTC.

The in-house approach ensures McLaren can constantly innovate monocoques to accommodate new technologies or new models, without compromising the qualities that ensure its chassis are the lightest, stiffest and strongest in their class.

The MCLA monocoque is taller around the A- and B-pillars than previous McLaren monocoques, as it integrates additional strength and load-bearing functionality into the carbon structure, replacing bonded metal parts. The windscreen surround is also carbon fibre. To achieve the requisite battery and fuel-tank safety cell, the sides of the monocoque extend back beyond what would traditionally be seen as the rear bulkhead. This provides side impact protection for the battery pack and also the fuel tank.

There is an exacting tolerance to the monocoque dimensions of +0.75mm across the structure with the tightest tolerances between machined features down to +/-0.25mm. This is fundamental to factors such as the accuracy of the suspension geometry control. Additionally, the high torsional rigidity of the monocoque ensures less compromise for the flexibility of the suspension itself, further enhancing the unique balance between a supple ride and precise handling.

The structure also plays a role in aerothermal optimization. Chamfered corners at the trailing edge of the front wheelarches guide airflow out of the arches and along the underside of the doors. The extended outer skin of the doors traps the air in this channel and it is driven rearwards into intakes that feed the lower portion of the high-temperature radiators (HTRs).

Chassis structure

Situated at either end of the carbon fibre monocoque are aluminum subframes that provide the Artura’s deformable crash structures. Designed to absorb impacts, the structures can be repaired or replaced easily and very cost-effectively. Cars with a full aluminum or steel chassis use their entire structure to absorb and crumple on impact, causing more damage to the whole structure, often including the passenger cell.

On the Artura, the front upper wishbone is mounted to the carbon monocoque, while the lower wishbone is attached to the aluminum crash subframe. The rear subframe is bolted to the monocoque, with the carbon fiber floor beneath the battery bridging the lower cross members transversely across the vehicle, ensuring the required torsional stiffness and optimizing the rear frame weight. The length of the lower portion of the frame is shortened to accommodate a bespoke rear diffuser, and the geometry of the new multi-link wishbone rear suspension concept is particularly aggressive.

Electrical architecture

Just as the carbon fibre monocoque incorporates greater functionality than any previous McLaren structure, so too does the electrical system. The Artura debuts an array of firsts for McLaren, including advanced driver-assistance systems (ADAS), Over-The-Air (OTA) software updates and Pirelli Cyber Tyre® tyre-monitoring technology. These are all made possible by the new electrical architecture, which also supports an all-new McLaren Infotainment System (MIS II).

Additionally, the complex powertrain necessitated an electrical architecture that can control McLaren’s first gasoline direct injection (GDI) fuel system at 350 bar; completely new transmission software; the E-differential and e-reverse functionality; battery management and implementing the different types of driving experience via the integration of the electric drive and engine drive.

To achieve all of this, McLaren is one of the first-to-market with a zonal domain-based ethernet architecture as the core backbone of the vehicle. The technology is the stepping point towards the industry trend of vehicle architecture redesign

The domain-based ethernet system utilizes four controllers, each positioned in a key area within the vehicle to optimize data rates and cable lengths. Placed in the same zones as the loads they control, the controllers are connected, via ethernet, through a central gateway. Linked functions at the front, rear or across the vehicle don’t need independent wiring and control systems, but instead, transfer data via this central ‘backbone’.

By moving to a single standard, all communications can coexist on the same ethernet network. Spreading outwards from each domain, data transfer still occurs via LIN (Local Interconnect Network) and CAN (Controller Area Network) for subsystem communication but processing power has increased. The use of domain-based technology has reduced the length of cabling in the vehicle by 25%, reducing weight by more than 10%.

This has been achieved while at the same time significantly upgrading the electrical capability of the vehicle – and adding new technologies such as the advanced driver-assistance systems (ADAS) features that debut in the McLaren Artura. The processing tools are integrated, with centralized software that can be constantly scaled and upgraded as new functionality becomes available, creating a platform that can adapt to future legislation and technology.

The advantage of this will most immediately be obvious to the owner because it allows for Over-The-Air (OTA) updates. When connected via wi-fi, either at home or via a hotspot, the vehicle is able to download new software when it becomes available. Updates related to vehicle safety will require a visit to a McLaren retailer, but OTA updates mean the customer can spend more time in their vehicle and instantly enjoy the benefits of newly downloaded functionality.

Working across all of these systems are new cybersecurity protocols, with enhanced algorithms. And in addition to OTA updates, depending on the market the new electrical architecture includes integrated stolen vehicle tracking within the telematics as well as E-call, which can dial emergency or recovery services in the event of an accident or breakdown.

eHVAC system

The new Artura platform also incorporates a new electric heating, ventilation and air-conditioning (eHVAC) system, designed to work with or without the assistance of the internal combustion engine. The compact unit, incorporating an electric compressor, condenser and evaporator, is located in the front of the car to improve weight distribution, without the need for ‘pipework’ to run forward from the engine. Not using the internal combustion engine to drive the compressor allows optimal control of compressor speed for better cooling in arduous conditions.

The eHVAC system is able to heat or cool quicker than a conventional HVAC system and provide greater precision between chosen temperatures. It uses a diffused vent that runs horizontally across the dashboard. This design increases flow into the cabin at lower velocities and with consequently improved occupant comfort and reduced system noise.

High-Performance Hybrid powertrain

The benefits of a High-Performance Hybrid powertrain are already in evidence in McLaren’s current range with the Speedtail – and of course previously from the McLaren P1™. The Speedtail has the greatest power and torque of any McLaren road car, with a combined 1,070PS (1,055bhp) and 1,150Nm (848lb ft) and even though it is an ultra-limited hypercar, the exhaustive development that produced it – and the philosophy of greater efficiency and lower emissions without compromising performance – helped to define the Artura’s unique attributes of hypercar innovation in a series-production supercar.

The Artura’s hybrid powertrain combines an all-new twin-turbocharged six-cylinder petrol engine together with an industry-leading axial flux electric motor (E-motor) integrated within an all-new eight-speed transmission and a lithium-ion battery pack.

The combined output of the High-Performance Hybrid powertrain is 680PS and 720Nm, with the torque of the E-motor ensuring instant throttle response. Straight-line acceleration of 0-100km/h (62mph) is achieved in 3.0 seconds and 0–200km/h (124mph) in just 8.3 seconds; yet at the same time the Artura is capable of driving up to 30km on battery power alone, making the car fully zero-emissions capable for most urban journeys. The cleanest and most efficient McLaren road car ever, the Artura returns more than 50mpg and 129g/km CO2 on the EU WLTP cycle*.

The McLaren Artura has four Powertrain modes, covering every driving requirement: E-mode, Comfort, Sport and Track. E-mode is the default for silent start-up and zero-emissions, fully-electric driving. In Comfort mode, the V6 petrol engine runs in tandem with the E-motor, with maximum assistance for fuel saving. In Sport model, the E-motor provides torque infill at lower revs, while the V6 targets maximum performance. Track mode delivers the same blend of hybridized power, with transmission software delivering faster shifts.