BODY
Dynamic, sports saloon styling
Extensive use of weight saving materials including aluminium body panels
High tensile steel contributes to excellent body rigidity
Active Noise Cancellation (ANC)
Advanced Compatibility Engineering (ACE) Body Structure disperses collision forces over a larger frontal area
5-star Euro NCAP rating anticipated for occupant safety, 3-star for pedestrian safety
Pop-up hood key factor in boosting pedestrian safety
Optional Adaptive Cruise Control (ACC) and Collision Mitigation Brake System (CMBS)
Optional Lane Keeping Assist System (LKAS) (right-hand drive only)
The Legend's taut, athletic shape conveys its performance credentials without sacrificing comfort and capability. Key elements include short overhangs and wide interior dimensions for enhanced comfort and convenience.
The dramatically sloping hood leads down to an aggressive nose with angular headlamp treatment, five-sided Honda grille and distinctive lower air intake openings. A sleek cockpit with flush glass, forward sloping beltline and short tail accentuate the Legend's pronounced wedge shape, and contribute to the excellent aerodynamic efficiency, low drag and high stability characteristics.
Compared to the previous Legend, the new model is 20 mm taller and 25 mm wider. Overall length has been reduced by 38 mm and the wheelbase by 110 mm, yet the cabin length available to passengers has actually increased by 30 mm, while internal width is 40mm greater.
Weight saving materials
A variety of measures have been implemented to reduce weight, at the same time increasing rigidity, in keeping with a premium luxury sport saloon. Strong performance in impact tests has naturally also been a high priority. Honda anticipates an overall 5-star rating in occupant safety and a 3-star pedestrian rating in Euro NCAP testing; a pop-up hood that is activated if a pedestrian is struck by the front bumper makes a significant contribution to the Legend's performance.
Measures to reduce body mass include:
Aluminium hood, front wings and boot lid
Aluminium front and rear subframes, suspension arms and bumper beams
Magnesium seat frames
Carbon fibre reinforced plastic propeller shaft
High-tensile steel
The Legend delivers a high level of bending and twisting rigidity and extensive extra-strength steel plays a key part in achieving this. Among the measures are:
Extremely strong high-tensile steel used for the side sills, under-floor spars, and in the impact-absorbing crumple zones at the front of the side frames
Strong high tensile steel used on the front shock mounts, areas of the front passenger-compartment bulkhead, areas of the front subframe mounts, and rear structure
Blow formed aluminium components
The aluminium front wings and boot are formed with an innovative process called blow forming to achieve complex and pleasing shapes with a high level of quality and light weight. This entails the raw aluminium panels being placed in a heated mould and warmed to 500 degrees Celsius. The introduction of a high-pressure gas results in perfectly formed complex shapes that are not possible with traditional stamping methods.
For rigidity, the boot lid is composed of an inner structural panel and an outer body panel, crimped together with a self-piercing rivet that makes the assembly highly durable.
Aluminium subframes
The components of the Legend's front and rear aluminium subframes are manufactured using high temperature bulge-forming and high vacuum die casting techniques. Both result in significantly lighter units than would be possible with either aluminium hydroform or steel hydroform processes.
To bulge-form these components, an aluminium tube is heated and pressurised with air inside a specially shaped die. The ability to shape the component under both heat and pressure means that less material can be used, lowering the overall weight of the finished component.
Aerodynamics
A highly efficient aerodynamic drag coefficient figure pays dividends in the form of lower wind noise, improved fuel economy, increased performance, and enhanced stability. Key elements include a front spoiler that reduces front lift force, a rear boot spoiler, and a particularly aerodynamic cabin area. The Legend is the first car in the world to have totally flush side glass where it meets the B-pillars. Normally, a gap of about 5 mm exists between side glass and the B-pillar, but on the Legend, the window guide is on the glass instead of the window frame, which has allowed the gap to be eliminated. This means there is one continuous, uninterrupted plane running along the front side window, across the B-pillar and all the way to the trailing edge of the rear side window. The benefit is a further reduction in wind noise and an even cleaner, high quality appearance.
Other features that contribute to aerodynamic efficiency are an engine undercover and further floor undercovers which smooth airflow beneath the car, while a rear diffuser helps with cooling the rear axle and reduces rear lift force.
To decrease wind noise levels, improve appearance, and improve occupant visibility, the Legend also incorporates windscreen wiper pivots and wiper arms that are hidden underneath the trailing edge of the hood.
NVH countermeasures
The elimination of undesirable noise, vibration and harshness (NVH) was of primary concern to development engineers. Virtually everything that could be the source of these traits was scientifically reviewed and modified during the planning and prototype phases.
The new Legend dramatically reduces high frequency and middle-frequency noise attenuation. Road noise attenuation is also significantly improved over both smooth and rough roads. In the drive to reduce weight, lightweight materials have been used wherever possible in the sound-absorbing package, including lightweight sound insulators instead of traditional heavier materials. In particular, a high performance acoustic material replaces separate absorptive and reflective layers and offers better in-cabin acoustics, absorbing rather than reflecting in-cabin generated noise.
Main NVH countermeasures:
Drivetrain:
Electric controlled engine mounting system including a hydraulic lower transmission mount
Variable volume exhaust silencer
Hood and dashboard outer insulator
Engine cover and undercover
Body:
Acoustic roof lining and rear inner wing
Acoustic front and rear inner wing insulator with high-frequency damping materials
Flooring:
Lightweight floor insulator
Floor undercover
Subframes:
Floating front and rear subframes with four mounting points
Interior:
Active Noise Cancellation
Lightweight instrument panel damping materials
Thinsulate insulation in selected areas
Boot:
Acoustic design with side, front and lid linings
Active Noise Cancellation
In a further innovation, the new Legend features Active Noise Cancellation (ANC) which is designed to dramatically reduce low frequency exhaust booming noise in the interior.
The system uses two microphones, one located just behind the front overhead console, the other just ahead of the overhead rear light module, to monitor low-end drivetrain frequencies entering the cabin. This information passes to the Active Noise Cancellation unit which in turn creates a precisely timed reverse phase audio signal that is sent to an amplifier, which then powers the audio system's door speakers and subwoofer.
In the frequency range below 100 Hz, ANC is capable of an impressive 10 dB reduction in noise level. A particular benefit of the system is that it replaces sound insulating material which would add further weight to the car.
Further noise suppression is achieved by a special valve system located in the exhaust system. Balancing the engine's need for proper exhaust backpressure at low speed and free flow at high speed, the valve opens when engine speed reaches about 3500 rpm to allow the flow rate to increase from 130 to 150 litres per second.
This results in a compatibility of a quiet interior, sporty exhaust and high power.
High quality paint
The new Legend's paintwork features greater lustre and more depth of colour thanks to a new application process which makes greater use of water borne paint for fewer emissions.
Following the application of the electrodeposition primer – cured at high temperature to improve corrosive durability – just one primer surfacer coat is applied. Previously a second coat was applied to achieve the necessary smoothness, but now the single coat is hand-sanded to obtain a better finish.
After a water-borne base coat is applied, a pair of clear coats (just one previously) is applied to provide depth and a more pollution and scratch resistant finish.
Source: Motor Corporation
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