2017 Honda NSX

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1. New #honda #nsx - Bringing a ‘New Sports eXperience’ to the supercar segment

• Honda melds timeless sports car values with next-generation technologies to create a New Sports eXperience
• Human-centred supercar development places an uncompromising focus on the driver
• The most intuitive and advanced sports hybrid power unit in the supercar segment
• Innovative new multi-material body with world-first material applications and construction processes allows lighter weight with increased strength
• Dynamic exterior design integrates supercar aesthetics with supercar performance

Specifically created to bring a ‘New Sports eXperience’ to the supercar segment, the #nsx challenges prevailing beliefs about supercars, just as the first generation #nsx did so comprehensively over a quarter of a century ago.

When the original #honda #nsx made its debut in 1989, it forever changed the supercar segment by offering dramatic supercar styling, performance and dynamics and breaking new ground in terms of quality, ergonomics and usability.

By making use of advanced new technologies, such as a lightweight yet rigid all-aluminium monocoque body and chassis, mated to a mid-mounted transverse V6 engine, the original #nsx challenged conventional supercar wisdom. Its high-revving engine featured a number of innovative production technologies, including forged pistons, titanium connecting rods and VTEC valve train.

Moreover, the #nsx sought a more intimate connection between driver, car and the road, pursued through essential design elements – low vehicle mass, high power-to-weight ratio, a rigid body supporting a performance-focused chassis, outstanding visibility, exceptional ergonomics and accessible performance. The result was a paradigm-challenging definition of a supercar.

Importantly, the first generation #nsx also exemplified Honda’s high standards of quality, durability and day-to-day usability, without compromising performance – something rarely found in supercars of the day. 

Respecting the core characteristics and differentiators of the original #nsx, the new #honda #nsx pursues an altogether new and revolutionary idea for #honda supercar performance, melding timeless sports car values with next-generation technologies to create a New Sports eXperience. Just as Honda’s precision crafted performance DNA guided the creation of the original #nsx, every aspect of this new design is accordingly a next-generation expression of those same values.

As a twenty-first century ‘human-centred supercar’ and the ultimate representation of #honda performance and prestige, the all-new #nsx is the #product of nearly four years of intensive effort by a global design and engineering team. Based on the man-machine synergy approach that guides the development of all #honda vehicles, the company created a driver-centred supercar in which every part of the vehicle is respectful of the smartest part of the car – the driver.

Foremost among its many innovations is Sport Hybrid Super Handling All-Wheel-Drive (Sport Hybrid SH-AWD), a first-of-its-kind technology in the supercar arena. By combining this new interpretation of #honda Super Handling performance with innovative approaches to vehicle design – including advanced body construction, component packaging and aerodynamic optimisation – the #nsx faithfully translates the acceleration, steering and braking inputs of the driver with incredible fidelity and with instant response. It amplifies the capabilities of every driver, and greatly elevates the dynamic experience in every driving situation.

Through Sport Hybrid SH-AWD, the #nsx is the world’s first supercar to utilise hybrid electric motors to enhance and elevate every element of its dynamic performance: acceleration, braking and cornering. With electrically powered torque vectoring provided by the front-mounted Twin Motor Unit, the #nsx takes #honda Super Handling All-Wheel Drive technology to a new level – using the dynamic, instantaneous and continuous distribution of electric motor torque to enhance the precision of handling and cornering performance in all driving situations.

The revolutionary #nsx Sport Hybrid SH-AWD power unit and its advanced dynamic capabilities are supported by new concepts in supercar design and body construction. The NSX’s multi-material spaceframe is a clean-sheet design, utilising a multitude of materials and joining technologies, each chosen for its unique capabilities to deliver unrivalled body rigidity in combination with low mass, outstanding visibility and class-leading occupant and crash protection. The NSX’s multi-material body integrates several world-first technologies, including three-dimensionally-bent ultra-high-strength steel A-pillars and ablation-cast aluminium frame nodes.

Likewise, the design and packaging of the Sport Hybrid power unit’s components – engine, transmission, motors, batteries and control systems – are optimised to support and enhance its dynamic capabilities by lowering the centre of gravity and centralising the mass within the car.

The new #nsx is Honda’s flagship model and the ultimate expression – in series production form – of Honda’s vision for sporty and advanced vehicles. With first deliveries to European customers expected in autumn 2016, the #nsx represents a critical step in re-establishing the Honda’s passion for performance enabled by advanced technologies.

2. Dynamic exterior design integrates supercar aesthetics with supercar performance

• Exterior design shaped by concept of total airflow management
• Maximum energy is harnessed from the airflow
• Carefully balanced downforce produces minimum drag
• Effective and highly efficient thermal management

“The idea that form follows function is fundamental to #honda design. This philosophy is interwoven in the core of #nsx, which is why our exterior concept is called ‘Interwoven Dynamic’,” said Michelle Christensen, exterior design project leader in the Los Angeles-based #honda Design Studio. “The #nsx is a visual expression of beautiful design and performance working together, influencing every decision we made – every surface, every millimetre, every design element of the new #nsx is focused on enhancing performance.”

The exterior design of the all-new #nsx reflects the integration of supercar aesthetics and exceptional supercar performance. The ‘Interwoven Dynamic’ overarching design theme for the exterior architecture epitomises the concept of form following function, as every character line, body panel shape or crease, air flow inlet and outlet, and even the vehicle’s overall proportions have been designed to create a New Sports eXperience. Accordingly, each aspect of the NSX’s exterior architecture has been optimised to support the dynamic capabilities of the #nsx while advancing #honda design into the future.

Every element of the NSX’s exterior serves a distinct purpose, one that has been carefully calculated through thousands of hours of complex computational fluid dynamics (CFD), in combination with extensive wind tunnel testing of 40 percent-scale and full-size models in the company’s advanced testing facilities in the United States and in Japan.

The acutely angled slope of the sculpted aluminium bonnet combines with the rakishly shaped LED headlights and tapered front grille to create an aggressive interpretation of Honda’s now-familiar family face. The distinctive multi-LED headlights are bisected by enlarged mesh-covered air inlets, while the front wings are accentuated by a sharply creased character line running all the way from the grille to the slender A-pillars.

Remarkably compact overhangs, front and rear, embody the exemplary packaging of mechanical and electrical components, while the sleek yet muscular overall stance conveys a sense of purpose and power. The bonnet line, roofline, floating C-pillars and rear quarter appear as one distinctive and unified curve. The large yet lightweight high-performance wheel and tyre package fits within the wheel arches with minimal gaps to highlight the taut proportions.

The rear of the vehicle is equally striking, emphasised by the signature floating C-pillars, which cascade gently from the roofline to forward of the integrated spoiler at the tailing edge of the rear deck, flanking an expansive glass panel that reveals the twin-turbocharged V6 engine.

Further accentuating the exterior architecture of the new #nsx are a choice of eight paint schemes, each carefully selected to accentuate the exterior’s bold design while achieving the highest levels of paint quality within the supercar segment.

Total Airflow Management

To support the NSX’s ambitious performance targets, innovative packaging design and dramatic styling, Honda’s engineers completely reimagined the exterior engineering for this modern supercar so that maximum energy is extracted from the flow of air around and through the #nsx with the highest efficiency.

This ‘total airflow management’ strategy supports complete power unit cooling and air intake, brake system cooling, and aerodynamic performance – drag and downforce – to an advanced level, offering unprecedented balance and confidence to enhance the driving experience.

There are seven different primary heat sources – the 3.5-litre V6 engine, two turbochargers, the nine-speed Dual Clutch Transmission (DCT), the Power Distribution Unit and the two motors within the Twin Motor Unit. To provide efficient cooling to each of these elements, airflow is managed through 10 different heat exchangers.

Openings at the front of the vehicle supply cooling airflow across the key heat exchangers located within the front section – front engine radiators, twin motor unit cooler, condenser, transmission gear cooler and hybrid Power Distribution Unit.

The airflow follows carefully optimised exit paths, which take into consideration total airflow, maximum downforce and a low coefficient of drag. The total airflow management approach results in a further consideration: exiting air is specifically manipulated to achieve a downstream flow pattern to feed the mid-engine air inlets.

Vents specifically positioned to reduce turbulence and aerodynamic loss around the front wheels work in conjunction with the hood and front fender vents to stabilise airflow down the side of the car to provide airflow to the signature side intakes, channelling it then to the engine intake, engine bay cooling, and turbo intercoolers. The side intakes are also designed to direct airflow over the rear deck to increase downforce.

Air flowing over the roof and down the rear hatch glass is captured to feed the transmission clutch cooler and facilitate engine bay cooling. A rear diffuser works together with the rear spoiler and taillight slots to generate significant downforce and effectively manage the drag created by the aerodynamic wake generated behind the car.

Total airflow management ensures the NSX’s exterior minimises aerodynamic drag while creating balanced front-to-rear downforce. An exhaustive research and development programme determined that placing approximately three times as much downforce at the rear relative to the front of the car would provide the optimal downforce balance for high-performance and day-to-day driving. The NSX’s high level of downforce is accomplished without the need for active aerodynamic bodywork or other devices.

Airflow management vents and precision ducting create strong, consistent downforce for the #nsx and were tuned with aerodynamicist and designer input during wind tunnel test sessions. Six vortices flow at the rear, including those that support the highest downforce across the rear deck lid. Air flowing from below the car and exiting through carefully optimised rear diffuser fins is a critical vortex that further anchors the #nsx to the ground. Uniquely, the fins are not parallel to each other, but are narrower toward the front of the car and wider at the rear. This design amplifies negative pressure, enhancing diffuser efficiency, which produces greater downforce.

The #nsx aerothermal team evaluated the thermal loading in racetrack conditions, using both a chassis dynamometer and wind tunnel. In addition to simulating key performance parameters, such as engine speed and braking, the test included varying wind speeds based on real-world track data. Simulations included Sebring International Raceway and Virginia International Raceway, the latter serving as one of the primary development tracks for the new #nsx.

Computational fluid dynamics (CFD) was used extensively during development to maximise the performance of all flow structures around the vehicle, to support hands-on experiments in wind tunnels during exterior design, and to optimise the thermal performance of the power unit. Firstly, for the proof-of-concept in establishing heat management strategy at the earliest development stage; and secondly, for continuous thermal performance improvement as the vehicle matured through development.

Along with the use of advanced CFD, wind tunnel and real-world testing, the development team also employed computerised lap-time simulation models of some of the world's most legendary proving grounds that could then be run on chassis dynamometers, allowing testing and validation of computer models for thermal management.

NSX underwent extensive testing at the company's state-of-the-art wind tunnel in Raymond, Ohio, using ultra-detailed 40-percent-scale models that replicate the suspension, wheels, tyres, intake and exhaust vents, heat exchangers and major under-bonnet components. The #nsx was then verified and further refined through testing at full scale in the company's wind tunnel in Tochigi, Japan and on real and simulated proving grounds throughout the world.

Floating C-pillars

The floating C-pillars integrated into the exterior architecture of the all-new #nsx are as purposeful as they are distinctive, supporting efficient body-side airflow. The C-pillars extend outward from the sloping rear roofline so that, as air flows down the sides of the vehicle, it is efficiently rerouted into the side-mounted engine air intakes. The floating C-pillars also aid engine cooling by creating a negative pressure zone around the rear heat exhaust vents, along the outside edges of the rear windscreen, improving the efficiency of heat loss. The portion of air that flows down the side of the vehicle toward the outside section of the buttress is conditioned to reduce turbulence as it passes with minimal disruption over the rear wing and spoiler.

Door handles and boot access

The flush-fitting exterior door handles are both aesthetically pleasing and functional, extending outward from the door for use while at the same time supporting clean airflow along the body side when in motion.

The boot is accessed by means of the remote key fob, by a button located on the driver’s interior door panel, or by a button discretely located under the trailing edge of the boot lid. In the event of a loss of power, both the driver’s door and the boot also feature a traditional key cylinder for manual locking or unlocking of the doors and boot.

Supercar wash / wipe system

The wash / wipe system, engineered specifically for the new #nsx, has been designed to operate effectively, even at maximum vehicle speeds. Tested in the wind tunnel at an airflow equivalent of over 290 km/h (180 mph), the spoiler-shaped wiper blades have been designed to generate downforce on the wiper blade, while the speed-controlled wiper motor maintains a constant wiping speed, ensuring highly effective wiper performance in all driving conditions. Likewise, the windscreen washer system utilises a three-nozzle system for superior coverage in all conditions and driving environments, including high-speed travel. 

Further contributing to the enhancement of forward visibility and the provision of an unobstructed view of the road, the windscreen wiper arms are placed as low as possible at the base of the windscreen so that they remain completely out of the driver’s view when not in operation. Placing the wipers below the bonnet also helps reduce wind noise.

Door mirrors

Featuring a two-tone paint scheme that accentuates the NSX’s ground-hugging appearance and wide stance, the door mirrors include a thin blade arm to minimise air turbulence as air flows along the side of the vehicle. This reduces local airflow noise, prevents disruption of air flowing to the side intakes, and minimises aerodynamic drag. In keeping with the ultra-high-strength A-pillars, the thin blade arm design improves visibility when parking and cornering. Each mirror housing includes an LED indicator.

LED Lighting

The exterior design of the all-new #nsx includes a variety of light-emitting diode (LED) lighting features, including LED headlights, LED daytime running lights, and LED tail lights. Designed to complement the exterior’s low and wide stance, each headlight assembly contains six individual LEDs, with four in operation when using the low beam setting (utilising the four outer LEDs) and employing all six LEDs when the high beams are activated. 

The headlight LEDs provide superior down-the-road illumination with outstanding light distribution and light characteristics with a wavelength close to the human eye's luminosity curve. With their streamlined shape and lower electrical power consumption, the NSX’s LED headlights also aid fuel efficiency and have a longer operational life compared to traditional halogen or high-intensity discharge (HID) lamps.

Occupying the top half of each LED headlamp that makes up the headlight assembly are the NSX’s LED daytime running lights. Located just beneath the LED headlamps are the LED position lights, composed of a series of small and tightly packed LEDs that run in a thin continuous line along the bottom of the headlight assembly. LED lighting is also used for the turn signals at both the front and rear of the vehicle.

This integrated LED-based lighting system creates a design aesthetic that complements the smooth, flowing and streamlined character lines of the vehicle, rather than calling individual attention to the daytime running lights themselves. Most importantly, the design featured on the new #nsx provides vivid illumination that can be easily seen by pedestrians or other vehicles during daytime hours.

Similar in character to the headlights at the front of the vehicle, the LED tail lights have a compact and narrow appearance with a uniquely freeform shape. The LED tail light array starts off wider, toward the centre portion of the rear of the vehicle, then gently tapers as it wraps around towards the outside corners and rear wheel arches.

Exterior finish

The highest levels of paint quality with reduced environmental impact were targeted at Honda’s innovative new Performance Manufacturing Centre (PMC), consistent with the ethos of ‘next-generation quality and craftsmanship’.

The NSX’s exterior body panels are not attached to the spaceframe until the conclusion of the vehicle assembly process. As a result, body panels are treated and painted separately from the frame and are finished to an exceptional level of quality and lustre by expert technicians at the PMC.

NSX body panels enter the paint process attached to a specially designed fixture that locates the panels in a position and angle similar to how they are oriented once installed on the vehicle. All body panels are covered with a high-quality primer coat and, depending upon the specific colour application, then receive between five and seven coats of paint. Each layer of coloured paint applied to the body panels is allowed to fully cure prior to the next application. A high-quality and durable clear coat is then applied.

To help minimise the potential for ‘orange peel’, which occurs when the clear coat on vertical body panels is pulled down by gravity during the curing process, the body paint fixture has hinges that allow the vertically oriented body panels – doors and wings – to be rotated to a near-fully horizontal position during the curing process. Once cured, the panels undergo careful inspection in a newly designed inspection booth utilising high-intensity LED lighting to help the craftspeople identify and address even the smallest irregularities. Body panels are then hand finished after the first layer of clear coat, and again after the second clear coat.

3. The most intuitive and advanced sports hybrid power unit in the supercar segment

• Honda’s new Sport Hybrid SH-AWD is the most sophisticated and advanced power unit in the supercar segment
• Twin-turbocharged V6 engine produces 507 PS
• Nine-speed Dual Clutch Transmission with Direct Drive Motor
• Front-mounted Twin Motor Unit contributes to almost instantaneous acceleration and superior dynamics

The exceptional dynamic capabilities of the new #nsx are enabled by its revolutionary Sport Hybrid Super Handling All-Wheel Drive (SH-AWD) power unit, the first such system of its kind in a supercar to utilise electric motor torque in combination with engine power, to enhance every element of dynamic performance – acceleration, handling and braking.

At the heart of the new Sport Hybrid power unit is a bespoke, mid-mounted twin-turbocharged V6 engine, paired with an all-new nine-speed dual clutch transmission (9DCT) and Direct Drive Motor that supplements the engine with instant torque response. Together, these components comprise the rear power unit. Amplifying the instant responses and dynamic handling performance of the #nsx is the front Twin Motor Unit (TMU), with two electric motors independently driving the left and right front wheels.

The NSX’s Sport Hybrid power unit offers exceptional horsepower and torque with a broad powerband for tremendous throttle response and acceleration. Total system peak output is 581 PS: 507 PS from the gasoline engine and 74 PS from the front TMU and Direct Drive Motor.

By creating a propulsion system that makes use of both mechanical and hybrid-electric components rather than just a conventional gasoline-powered internal combustion engine, the NSX’s power unit is able to create constant and linear acceleration at any point in the power band, at any speed with instant response.

At initial launch from a standstill, the front-mounted Twin Motor Unit (TMU) and the direct drive electric motor are able to immediately supplement power production from the twin-turbocharged V6 engine, using the abundant and instantaneous torque production that is an inherent characteristic of electric motors. Conversely, once the vehicle has reached a steady cruising speed, the twin-turbocharged V6 engine becomes the primary motive force for the vehicle, with the three electric motors providing supplementary power and yaw control when necessary.

While the primary focus in the development of the all-new NSX’s clean-sheet power unit was peak performance, efficiency and environmental sustainability were also important design characteristics. Therefore, the all-new #nsx meets ultra-low emissions vehicle (ULEV) requirements.

Rear Power Unit

Twin-turbocharged V6 engine

Featuring a wide V-angle of 75 degrees for a low centre of gravity, the NSX’s twin-turbocharged V6 engine achieves an ideal balance between power production, compactness and reduced mass. With a displacement of 3.5 litres, it combines both direct and port fuel injection, along with Dual Variable Valve Timing Control (Dual VTC) to deliver optimal camshaft phasing. Dual VTC allows for precision combustion control at all engine speeds while simultaneously achieving high power output and uncompromised performance at high engine speeds.

Other key engine design elements include a sand-cast engine block, lightweight and compact cylinder heads, and plasma transferred wire arc thermal spray-coated cylinder walls (for higher thermal efficiency with reduced weight and compactness). A dry sump lubrication system significantly reduces the engine’s centre of gravity while simultaneously ensuring consistent engine lubrication under high cornering load conditions.

The #nsx has a compact valve train utilising swing arm-type valve actuators, which allows for a more compact head structure and reduces by 22 percent the inertial weight of the valve train compared to a rocker arm-type design. The innovative design was derived from #honda racing engines. Intake and exhaust variable camshaft timing (VTC) is deployed to provide an excellent balance of high power, torque, fuel efficiency, and emissions.

The engine also features for the first time on a #honda a three-piece water jacket for the engine block and heads, including water jackets between the cylinder bores, a triple radiator system and a viscous damper mounted to the crankshaft.

Turbocharging system

Developing a bespoke twin-turbo system for the all-new engine was a logical choice, offering a strong balance of high power with considerable torque, high fuel efficiency and low emissions, while also offering inherent packaging advantages.

Through careful research, testing and development, Honda’s engineers were able to determine the ideal boost pressure for efficient and suitable power while simultaneously meeting Honda’s stringent benchmarks for reliability and longevity. Maximum boost pressure is set at 105 kPa (1.05 bar / 15.23 psi).

Increasing the engine intake air pressure increases intake air temperature, which, if not controlled properly, increases the risk of pre-detonation. To counter this increase, a high volumetric flow air-to-air intercooler is adopted, dramatically reducing intake air temperature while simultaneously increasing the density of the air intake charge for maximum power production.

Making use of an electronic wastegate for each turbocharger for fast response and precise control, the single-scroll turbocharger design allows for the use of smaller turbos to reduce weight and improve packaging while still meeting power and performance benchmarks.

Plasma transferred wire arc thermal spray coating

Utilising an aluminium engine block and heads presents three key advantages compared to traditional cast iron block and head configurations: greatly reduced mass, improved thermal conductivity, and improved heat dissipation. Most aluminium engines require the fitment of cast iron cylinder liners to provide sufficient wear resistance. Honda’s engineers addressed this issue by employing a plasma transferred wire arc thermal spray to the cylinder walls – a recently developed technique that offers an increase in heat transfer (thermal conductivity) of 52 percent with greatly reduced weight compared to cast iron liners.

The plasma transferred wire arc thermal spray process melts a thin-diameter wire down to an atomised form that can then be sprayed onto the cylinder walls. A supersonic plasma jet formed by a transferred arc between the tip of the wire and a cathode is used to spray the molten material, stacking the tiny particles on top of each other to form a very thin yet extremely wear-resistant coating.

Along with improved engine efficiency via reduction of internal friction, additional benefits from the plasma transferred wire arc thermal spray process include an approximately 3 kg decrease in overall engine weight when compared to iron cylinder liners, improved wear resistance, reduced oil consumption, increased horsepower and torque production, and enhanced throttle response.

Furthermore, thanks to the addition of plasma transferred wire arc thermal spray, additional water channels are able to be placed between the cylinder bores for improved cooling efficiency via better control of coolant flow.

Cylinder heads

Drawing on Honda’s extensive racing experience, the cylinder heads fitted to the twin-turbocharged V6 are highly compact and include smaller valve train components. This has resulted in a notable reduction of inertial weight as well as a 22 percent reduction in cylinder head mass when compared to conventional designs. This reduction in mass also helps lower the vehicle’s centre of gravity.

The cylinder heads utilise a three-piece water jacket for improved cooling efficiency along with improved coolant flow control. Additionally, the race-inspired cylinder head design optimises the swirling of intake air so that fuel mixes with it in a more ideal manner for improved combustion, improving efficiency and emissions performance.

High specific power output

With a compression ratio of 10.0:1, the NSX’s engine has a specific power output of more than 140 PS per litre of engine displacement. The engine safely and reliably achieves this high specific power output through a number of advanced engine technologies, including the efficient twin-turbo system, reduced friction and heat transfer properties of the plasma transferred wire arc thermal spray on the cylinder walls, sodium-filled exhaust valves, implementation of both direct and port injection, and the superior combustibility of fuel from the high tumble ports.

Dual Variable Valve Timing Control (Dual VTC)

The #nsx engine incorporates proprietary Dual Variable Valve Timing Control (Dual VTC) variable valve timing control technology, which delivers an excellent balance of high torque and maximum power output with reduced exhaust emissions and superior fuel efficiency.

At engine idle, Dual VTC stabilises combustion for smooth idling by minimising intake and exhaust valve overlap and, therefore, decreasing the amount of exhaust gas recirculation. During constant-speed driving or under light acceleration, the system reduces exhaust emissions and engine pumping losses by optimising valve overlap. Under wide open throttle at low engine speeds, the overlap of the intake and exhaust cam timing is expanded so that the turbochargers can work at maximum efficiency for optimal power delivery and responsiveness. Conversely, when operating the engine at high engine speeds, overlap of the exhaust and intake timing is minimised for improved volumetric efficiency to create maximum power. 

Direct and port fuel injection

The #nsx engine combines both direct and port fuel injection systems to provide for outstanding power production while simultaneously offering exceptional emissions performance.

Direct injection is the primary means of fuel delivery within each cylinder, while port injection is used for additional power output in high-performance driving situations. The direct injection system’s electric fuel injectors are mounted in the cylinder head and spray a very fine, highly atomised mist of fuel directly into each cylinder under very high pressure so that the fuel ignites almost instantaneously and completely, maximising engine performance and fuel efficiency with reduced emissions. Under high performance demands, the port injection system supplements the direct injection system, feeding fuel into the intake ports where it mixes with the incoming air for increased power production. 

The direct and port injection systems for the engine are fed by two specially designed fuel pumps, one feeding the direct injection system at a fuel pressure rate of 4.48 bar (65 psi), the other supplying the port injection system at a pressure of 3.52 to 5.03 bar (51 to 73 psi).

By optimising the direct injection system – precise control of fuel spray pattern, particle shape and size, and timing of fuel flow – with the operation of the engine’s twin turbochargers, Honda’s engineers were able to improve combustion efficiency and power output, also assisted by the high tumble intake port design. The approach ensures the necessary amount of fuel for maximum power output is always supplied from both the direct and port injection systems while optimising the combustion process of the direct injection and high tumble airflow within each cylinder for outstanding emissions performance. The production of hydrocarbons and particulates is reduced by avoiding fuel wetting on the piston and cylinder sleeve.

An advanced lean-burn combustion technology allows for homogenous and weak stratified combustion to occur within the cylinder, through ultra-precise control of the fuel injection. By ensuring that fuel spray angle and direction do not interfere with the intake valves, along with a strong air / fuel swirl from the high tumble port, high power output and low emissions are effectively combined. Along with optimised shaping of the piston head and intake port shape, the highly accurate and measured fuel spray and injection pattern play a pivotal role in this advanced combustion concept.

A two-into-one inlet manifold design minimises torque deviation between each bank of cylinders. Twin throttle bodies allow more air into the system and finer throttle control while simultaneously reducing the pulsation of air.

Exhaust system

Compact and lightweight, the stainless steel exhaust system includes two catalytic converters per cylinder bank and four outlets for excellent exhaust gas flow and low emissions. Silicon exhaust system mounts resist heat and firmly secure the exhaust system to the vehicle, helping to reduce vibration while ensuring system integrity and long life.

An Active Exhaust Valve (AEV) system has been developed that matches the exhaust note to the dynamic driving situation, operating as a complementary component of the Integrated Dynamics System. The system utilises two distinct exhaust paths controlled by two electrically-operated valves.

In Quiet mode, the exhaust valves are closed and the exhaust gases pass through silencers for a more subdued sound. In Sport mode, the exhaust valves are closed unless driver demand is high enough, at which point they open. In Sport+ or Track modes, the AEV system is open, bypassing the silencers for a full, uninhibited flow of exhaust gases and a voluminous and full-throated exhaust note.

Dry sump lubrication

In another application of race-bred technology, the all-new #nsx is the first production #honda vehicle to use a dry sump engine lubrication system. By replacing the engine’s conventional oil pan with a separate oil reservoir and a dedicated chain-driven oil pump mounted directly to the lower engine block, the system is designed to prevent oil starvation under high lateral G loads.

After being fed to the engine for lubrication, oil is collected from the lower engine block by six separate scavenger pump impellers and then fed back into the oil tank by a pair of pump rotors.

Importantly, the adoption of a dry sump lubrication system allowed designers to mount the engine 61 mm lower within the chassis, thanks to the elimination of a traditional oil pan. The more efficiently cooled oil also helps promote maximum engine power output.

‘Starter-less’ engine start system with idle stop

As a byproduct of its Sport Hybrid power unit, the #nsx utilises its Direct Drive Motor to start the engine in place of a conventional 12-volt engine starter motor.

Along with a significant weight savings, further mass reduction was realised by eliminating the 12-volt starter ring gear normally required by a conventional engine starting system.

To improve fuel efficiency further, the #nsx is equipped with idle stop capability. When the system is active and certain operating conditions are met, the engine will automatically shut off when the vehicle comes to a stop. The system is not engaged when Sport+ or Track modes are selected. When stopped, a special cold storage evaporator in the air conditioning system helps maintain a comfortable cabin temperature even in warm weather.

Engine restarts are exceptionally smooth and quick, supported by the use of the powerful Direct Drive Motor as an engine starter. Idle stop operation is also fully integrated into the operation of the Automatic Brake Hold system.

Engine balancing and running in

Honda’s engineers further improved engine performance and refinement through reduction in experienced noise, vibration and harshness (NVH). The latest in engine balancing technology and a number of new processes are applied to achieve optimal balance. These include the use of next-generation engine diagnostic equipment to more accurately measure engine imbalance, and the application of variable bolt weights that are applied to the eight mounting holes on the flywheel and the addition of nine mounting holes in the crankshaft viscous damper, which can be used for fine-tuning. Achieving a high degree of harmonic equilibrium not only greatly reduces engine vibration, but also decreases wear of the engine’s internal componentry for superior reliability and longevity.

The flywheel also acts as a mass damper. The inclusion of an integrated mass damper, or flywheel, is one of the most lightweight components that could be added to minimise mechanical and harmonic vibration caused by oscillation, thereby greatly reducing NVH while helping to ensure structural integrity and longevity of the transmission case.

As an important additional quality step prior to fitment within the #nsx, the engine undergoes a running in programme. The engine is placed under load on a specially designed engine dynamometer that simulates the equivalent of 150 miles of service.

Nine-speed Dual Clutch Transmission with Direct Drive Motor

The #nsx features a bespoke nine-speed dual clutch transmission (9DCT) which works in concert with the Direct Drive Motor to make full use of the power unit’s broad powerband, producing quick and precise gear changes that support the instant acceleration responses. As a key component of the power unit’s packaging, the 9DCT has been optimised for compact size, low mass and low centre of gravity.

The 9DCT has a very wide ratio range that allows for optimal gear selection via the competition-inspired, steering wheel-mounted paddle shifters in any driving condition. First gear ratio is configured for maximum vehicle launch acceleration, while the close-ratio gears (second to eighth) are matched to make the most of the power unit’s powerband. Conversely, top gear (ninth) has been optimised for fuel efficiency during constant high speed cruising. When driving in ninth gear on a level surface at 97 km/h (60 mph), the twin-turbocharged 3.5-litre V6 engine is spinning at only 1,700 rpm.

In order to achieve compact dimensions, the clutches and the differential are uniquely situated side-by-side in a common housing. The parallel shaft layout reduces overhang from the rear axle while the centre of mass is moved forward, which in turn reduces the length of transaxle assembly.

The 9DCT incorporates several advanced features. An electronically-operated wet dual clutch, high-rigidity shift fork, double-cone synchronisers for second to fifth gears, and an electronic shift actuator combine to synchronise shift timing precisely with power unit torque for the quickest and smoothest gear shifts possible. A precision surfaced high-efficiency hypoid bevel gear tooth shape for all gears ensures smooth operation and minimal gear noise. Two oil chambers within the transmission housing provide efficient and high-capacity cooling, while the inclusion of exclusive new gear oil ensures higher viscosity and improved lubrication throughout the gear train (when compared to a conventional heavier gear oil that increases viscous drag).

Customisable quick response gear shift system

One of the key evaluation parameters for Honda’s engineers was the speed with which the #nsx could change gear. To deliver superior gear shifting performance, the 9DCT features unique components within the gearbox to accomplish smooth yet almost instantaneous gear changes.

Highly rigid shift forks composed of a specialised, high-strength cast iron play a key role in providing a smooth yet quick shift response. The shift forks straddle the gear shaft with a ‘U’-shaped portion that engages with the selected gear, pushing it forward and engaging the gear within the gearbox. The 9DCT uses a total of five shift forks for the gear actuator system: a one-way clutch is used for first gear; four shift forks are used for second to ninth gears; and a fifth shift fork is employed for Park and Reverse.

Ultra-quick gear shift response and engagement with reduced weight is aided by the use of a compact electric motor as a gear actuator – as opposed to a conventional pneumatic or hydraulically operated gear actuator. This system reduces weight by eliminating the high-pressure hydraulic pump that is typically used in a gear actuator system, while providing for excellent reliability and system robustness when compared to other available gear actuation systems.

Similarly, an electrically operated clutch actuator eliminates the need for a high-pressure hydraulic pump. Control of the clutch is accomplished via a closed-circuit hydrostatic structure, which allows for the generation of oil pressure on demand as needed with greater efficiency.

The performance and shifting characteristics of the 9DCT can be through the transmission operation settings within the driving modes of the Integrated Dynamics System. In Quiet mode the transmission shift map promotes gear shifts at lower engine speeds. Sport mode allows the engine to rev more freely and makes gear changes at higher engine speeds. Sport+ mode accommodates higher engine speed gear changes with quicker, more aggressively executed upshifts and downshifts, while Track mode offers the fastest upshift speeds – 40 milliseconds faster than Sport+.

Limited-slip differential

The NSX’s responsive handling is enhanced by a mechanically-based limited-slip differential (LSD). Designed to deliver excellent poise and stability while maximising the performance of the power unit, the torque-sensitive multi-plate clutch is lighter and more compact than a similar unit with a helical gear configuration. Furthermore, the multi-plate design allows for improved wheel coupling for smoother and more efficient operation.

The torque bias ratio – an index for slip limit torque that compares torque shifted from a high rotation axle to a low rotation axle – has been optimised to provide two distinct LSD performance settings ideal for when the wheels are being driven or when the vehicle is coasting.

Engineered to complement the Twin Motor Unit (TMU) and Vehicle Stability Assist (VSA) systems with precision torque vectoring and enhanced traction maintenance, the LSD enhances vehicle performance in a number of driving situations. Under braking or when decelerating approaching a turn, the LSD increases engine braking torque on the outside wheel for improved vehicle stability. During straight-line driving, torque is transferred left-to-right as necessary for enhanced vehicle stability. Under acceleration or while turning, overall traction and poise is improved by shifting torque to the outside wheel as traction from the inside wheel decreases.

Rear power unit mounting

By employing widely spaced power unit mounting brackets – up high at the front of the engine along with a mounting cradle bracket down low at the rear (connected to the 9DCT) – the position of the rear power unit (engine, Direct Drive Motor and 9DCT) is optimised to significantly reduce roll, pitch and yaw motion, providing greater acceleration and handling response.

Sport Hybrid systems

The Sport Hybrid system is a suite of highly advanced components at the centre of the hybrid-based systems of the power unit. Each of its components is engineered to minimise both weight and size in order to reduce overall vehicle mass, and carefully packaged within the #nsx to lower and centre the mass of the vehicle. Collectively, the Sport Hybrid system includes the Twin Motor Unit (TMU), Direct Drive Motor, Power Drive Unit (PDU), and Intelligent Power Unit (IPU).

Twin Motor Unit (TMU)

The new NSX’s instant and linear acceleration coupled with outstanding dynamic capability is enabled in part by its front-mounted Twin Motor Unit (TMU). Designed to be as small and lightweight as possible while delivering ample torque and power, as well as precise torque vectoring to the front wheels, the TMU is a unique and highly efficient solution. The TMU provides supplemental power in conjunction with the twin-turbocharged V6 engine for instantaneous acceleration and provides true torque vectoring at any vehicle speed to enhance the NSX’s dynamic excellence.

In addition to instant torque, the TMU offers all-wheel drive (AWD) capability, allowing direct and immediate acceleration with a heightened sense of the associated G forces. Further, the TMU can dynamically apportion its torque to create a yaw moment, enhancing cornering performance. The TMU recovers braking energy during deceleration to supply power to the hybrid batteries.

Inside a die-cast aluminium housing, two 37 PS electric motors are positioned back-to-back. Each motor powers a single front wheel and can also apply negative torque to the same wheel. A gear mechanism allows the motors to decouple and still provide on-demand torque vectoring, helping to improve efficiency in certain conditions. To achieve these functions, the TMU uses a double pinion planetary deceleration mechanism, a separation mechanism and an oil pressure control system.

In order to achieve maximum acceleration from a standstill, and to meet Honda’s target of instant response, the TMU and Direct Drive Motor provide the initial accelerative force during acceleration from a standstill. After the first 0.15 seconds and 0.1 G from initial acceleration, the high horsepower and torque from the twin-turbocharged V6 engine becomes the primary acceleration force, supported by power from the Direct Drive Motor.

The TMU is also a key motive force for driving in the Quiet mode setting of the Integrated Dynamics System (IDS), allowing for hushed vehicle operation by powering the #nsx electrically for short distances.

Direct Drive Motor

The Direct Drive Motor, packaged between the twin-turbocharged V6 engine and the 9DCT, is an ideal packaging solution of an electric traction motor to provide additional torque and power assist to the rear wheels.

In order to help eliminate the response delay typically associated with turbocharged engines, the Direct Drive Motor acts directly on the engine’s crankshaft which, together with the TMU, supports the #nsx in achieving immediate, high-output, high-torque acceleration performance. The effectiveness of this design is particularly noticeable in everyday driving when accelerating from rest and at low engine speeds. Additionally, the Direct Drive Motor operates as a generator to help charge the hybrid batteries, while also acting as the engine starter.

The Direct Drive Motor features a liquid cooling passage that provides ample cooling and heat dissipation even when the system is being worked hard, such as during circuit driving.

Intelligent Power Unit

Neatly packaged in the cabin, just in front of the rear firewall, the Intelligent Power Unit (IPU) acts as the primary hub of the E-Drive system. The IPU integrates the lithium-ion battery pack, junction board, a high-voltage distribution bus bar, 12V DC/DC converter, electric motor/ECU, lithium-ion battery ECU and the ECU for the TMU.

As a result of integrating a next-generation lithium-ion battery pack and a caseless structure for key IPU components, the NSX’s IPU system is 35 percent smaller and 30 percent lighter than a similar IPU.

When driving in Sport, Sport+ and Track modes, the NSX’s air conditioning system is used for supplemental cooling of the IPU for optimal efficiency and performance. During development, the system was tested extensively in the desert heat of Dubai in order to ensure its proper function in extreme ambient temperatures.

Lithium-ion battery pack

Packaged within the IPU is the lithium-ion battery pack which stores the electrical energy to power the TMU and Direct Drive Motor.

The high-output lithium-ion battery pack consists of four modules, each with 18 individual battery cells (72 cells in total) contained within a specially designed caseless structure that utilises the vehicle body itself for a lightweight yet sturdy housing.

Incorporating the latest advancements in lithium-ion battery technology for automotive applications, both the positive and negative electrodes have been optimised for increased energy and efficiency. The battery pack is also the lightest and smallest to be engineered into any #honda vehicle. When compared to other #honda hybrid units, the #nsx battery pack’s power density (stored energy per kilogram) has been increased by 10 percent, while energy density has been raised by 15 percent.

Power output and efficiency of battery operation have been further improved by implementing a co-operative cooling system, fed by fresh cool air channelled into the passenger compartment via the air conditioning system. Cool air from within the cabin circulates through ducting to cool both the lithium-ion batteries as well as the DC/DC converter.

Power Drive Unit

The Power Drive Unit (PDU) dictates the power management strategy of the Sport Hybrid SH-AWD system, including motor power and battery recharge. The PDU also incorporates three separate converters (converting direct current to alternating current) for use by the power unit’s three electric motors: the twin motors of the front-mounted TMU and the Direct Drive Motor. This compact ‘three-into-one’ PDU design is critical to the system’s compact packaging and the ability to mount it centrally in the vehicle, in the centre tunnel beneath the centre console.

4. Innovative new multi-material body with world-first material applications and construction processes allows lighter weight with increased strength

• Multi-material body produces best-in-class rigidity
• Chassis rigidity supports instant response concept
• Innovative metal technologies contribute to light weight and rigidity

Honda’s engineers took a bold and challenging new direction to unlock the full potential of the NSX’s Sport Hybrid SH-AWD powertrain and fulfil the high targets set for its total dynamic performance. The resulting clean-sheet, multi-material approach breaks new ground in the automotive realm – with new materials, new construction methods and new thinking in supercar body design.

By starting from scratch, Honda’s engineers were able to choose the optimal material application and construction methodology for each area of the body, targeting both low mass and ultimate rigidity while also satisfying other critical design objectives. Accordingly, superior outward visibility, class-leading crash safety performance and world-class quality and durability befitting a next-generation #honda supercar were all accomplished.

The multi-material body, with its aluminium intensive spaceframe, is designed to achieve structural rigidity far superior to its best-in-class competitors. This high level of dynamic rigidity provides a crucial foundation for the NSX’s instantaneous responses. Accordingly, drivers will feel their inputs directly translated to the car’s actions with incredible speed and fidelity, while simultaneously allowing the maximum potential of the Sport Hybrid SH-AWD system to be realised – the essence of the New Sports eXperience. 

“The challenge for Honda’s engineers was to create a body with a high level of rigidity to be able to transmit the full feeling of this powertrain directly to the driver without delay,” said Shawn Tarr, chief engineer for the #nsx body development. “While the all aluminium unibody of the original #nsx was ahead of its time, we would need to look to world-first technology in order to achieve this new level of rigidity.”

The body construction – performed entirely at Honda’s Performance Manufacturing Centre (PMC) using domestic US and globally sourced parts – is undertaken with innovative new techniques and technologies, and with a commitment to quality unmatched in the supercar realm. MIG welding of the aluminium-intensive spaceframe, for example, is performed entirely by high-precision robots, with all welds and body components undergoing a detailed inspection by highly skilled PMC weld technicians. Building the spaceframe to such a high quality and accuracy eliminates the post-construction machining activity that is common in low-volume vehicle manufacturing. This commitment to next-generation quality through the optimum blend of machine precision and human craftsmanship is apparent in every aspect of the body construction, finishing, painting and assembly, and is clearly identifiable in the final #product.

Multi-material body and spaceframe

The multi-material body, with its aluminium-intensive spaceframe, offered Honda’s engineers the best structural rigidity and lowest platform weight with superior packaging for the power unit. NVH is also greatly minimised by the NSX’s global rigidity benchmarks – two times static and three times the dynamic level of torsional rigidity demonstrated by the next highest competing vehicle evaluated by Honda’s engineers.

Highly rigid and reinforced extruded aluminium beams comprise the majority of the spaceframe and are utilised for the front and rear frame rails and cross members, front and rear bulkhead frame members, floor cross members and side rails. A number of these aluminium extrusions are filled with acoustic spray foam to further aid noise attenuation, which is used in 38 different locations.

Cast aluminium nodes serve as joining points for the extruded aluminium frame members, as well as ultra-rigid mounting points for the front and rear suspension systems and the rear Sport Hybrid Power Unit. These nodes are either gravity die cast or – in front and rear crush zones – formed using advanced new ablation casting technology, a world’s first automotive application (see below for additional detail).

In another world’s first, the upper portion of the A-pillars and roof rails, which comprise one continuous section, are formed using three-dimensionally bent and quenched ultra-high strength steel tubing. This new metal forming process allows enhanced styling and outward visibility while providing high roof-crush strength (see below for additional detail).

Aluminium stampings are utilised as lightweight closure panels for the rear floor, rear bulkhead and B-pillars. The front floor panels are constructed from carbon fibre for strength and low weight.

Ablation cast nodes

One of the most difficult design challenges was minimising the front and rear overhangs while managing collision energy absorption in key areas, for crash safety performance and maintaining optimal structural rigidity. Honda’s engineers developed an innovative new technology called ablation casting – an all-new material application and a world’s first application in the automobile industry – to solve these complex and competing design imperatives. Ablation casting was matured from a fundamental research theme to production vehicle application within the development cycle of the new #nsx – a major design, engineering and manufacturing achievement.

Jointly developed with specialist company Alotech, ablation casting is utilised in the creation of six joining members, or nodes – two upper and two lower nodes in the front frame, and two nodes in the rear frame. These nodes also serve as ultra-rigid mounting points for both the front and rear suspensions and for the Rear Power Unit. The front upper nodes are designed to absorb and dissipate energy in a frontal collision. The two ablation cast nodes in the spaceframe at the rear of the vehicle are designed for high strength to mitigate forward movement of the power unit in the event of a severe rear collision.

Ablation casting involves the rapid cooling of a sand-cast aluminium component via the precise application of water jets, which ablate the sand mould while cooling the part. This process allows for the fine-tuning of both the cast part’s shape and its material properties while minimising weight with hollow forms and optimised wall thicknesses. Unlike traditional castings, the high-strength and ductile properties of the aluminium ablation cast members allow these sections of the spaceframe to progressively cr