12C SPIDER: THE DETAILS
As with the 12C, everything on the 12C Spider was designed for a reason. There is no unnecessary ‘jewellery’, no styling fripperies. It is a ‘pure’ sports car, designed to deliver maximum driving appeal and performance, with unmatched efficiency.
‘As with all McLarens, the 12C Spider is a racing car at heart,’ notes Design Director Frank Stephenson. ‘That is not true of many – if any – other high performance convertibles.
‘It has the same timeless elegant style that distinguishes the 12C but with the added romance of open-top driving,’ adds Stephenson. ‘We have tried very hard to preserve the same design purity. With the roof in place, it looks like a coupé sports car that could just as easily be at Le Mans, as in London or Los Angeles. With the roof down, it looks like it belongs on Sunset Boulevard or the Cote d’Azur.’
RETRACTABLE HARD TOP (RHT)
The Retractable Hard Top (RHT) has been designed specifically for the 12C Spider. Low weight, combined with high strength, was of paramount importance – as with all areas of the 12C.
The two roof panels and tonneau are made from the same composite material used in the construction of the 12C body. This is light, strong and allows for a very high standard of paint finish. Heated rear glass completes the roof construction.
The fully automatic mechanism raises or lowers the roof in less than 17 seconds, and can be activated at speeds up to 30 km/h (19 mph). It is controlled by a two-position switch on the centre panel within the cabin.
At the end of the roof lowering cycle, the windows fully close, and the rear glass adopts an ‘aero’ position that also reduces cabin wind buffeting. Continuing to hold the switch after the cycle is complete fully lowers the windows and rear cabin glass.
The RHT is operated by a single hydraulic pump. It is mounted as low as possible in the vehicle to optimise the centre of gravity, and improve handling.
DUAL PURPOSE TONNEAU COVER
When lowered, the roof stows beneath a body coloured hard tonneau cover which incorporates twin buttresses. With the roof raised, the area beneath the tonneau cover can be used as additional luggage space. This can accommodate 52 litres of luggage in two specially designed bags, supplied as standard. This is in addition to the 144 litres of luggage space provided under the bonnet.
RETRACTABLE REAR GLASS PROVIDES INCREASED AUDIBLE DRAMA
The rear glass can also be operated independently of the RHT. Roof up, the rear glass can be lowered to allow more engine sound into the cabin and also allows for a semi-open driving experience even in inclement weather. Roof down, the screen acts as a wind deflector, minimising disturbance in the cabin.
ROLL OVER PROTECTION SYSTEM
A roll over protection system ensures maximum occupant safety. Each rear buttress contains a steel structure to absorb the impact energy and protect both driver and passenger. An ‘active’ pop-up system would have added unnecessary weight.
CARBON FIBRE MONOCELL IDEALLY SUITED FOR CONVERTIBLE USE
As with the mechanically identical 12C, the 12C Spider is a mid-engine two-seat rear-drive high performance sports car. Unlike rivals, it uses a carbon fibre monocoque chassis, the MonoCell. This confers major advantages in weight, strength and torsional rigidity – all improving handling, ride comfort and performance.
The MonoCell is a unique one-piece moulded chassis that weighs just 75kgs (165lbs). It is 25 per cent stiffer than an equivalent all-metal structure and 25 per cent lighter than a comparable aluminium chassis (the difference with a steel chassis is even greater). It is also stronger and safer in a crash, acting as a safety survival cell, as it does in a Formula 1 car.
‘It provides the perfect combination of occupant space, structural integrity and light weight,’ explains Chief Engineer Neil Patterson. ‘It is the ideal chassis to deliver groundbreaking efficiency and performance in the sports car market.’
The MonoCell is unchanged from 12C to 12C Spider, as it was originally designed for both applications. ‘This is highly unusual,’ notes Patterson. ‘Most convertibles require a strengthened chassis to reduce flex, thus adding weight – while still not achieving the structural integrity of a coupé. This flex can compromise handling precision and reduce ride comfort; while the added weight affects performance.’
The carbon fibre MonoCell not only gives advantages in strength and weight, it also improves packaging. The one-piece moulded design has been created to provide the perfect cabin – roomy, yet compact. ‘We started with the driver,’ says Design Director Frank Stephenson. ‘With the 12C and 12C Spider, the driver sits close to the centre line of the car, improving control and driver enjoyment. The pedals are positioned inboard, reducing wheel well intrusion. The result is the perfect driving environment– unique and uncompromised.’
The steering column is centred on the driver, and is parallel to his seat and shoulders. The brake and throttle pedals are both placed directly in line with the driver and all primary controls are within reach. The overall cabin architecture is both elegant in its design and uncluttered and intuitive to use.
As with the 12C, the 12C Spider has class-leading all-round visibility. ‘Enormous emphasis was put on ensuring excellent visibility, both for safety and driving precision,’ adds Stephenson.
McLAREN: THE CARBON INNOVATORS
The carbon fibre MonoCell of the 12C and 12C Spider follows more than three decades of McLaren carbon innovation. In 1981, McLaren Racing introduced the carbon monocoque to Formula 1™. It offered an unbeatable combination of strength and weight-saving, and soon recorded the first victory for a carbon-based F1 car, at the British GP, driven by John Watson.
The legendary McLaren F1 road car, launched in 1992, was the first road car to use a carbon chassis and body. In fact, since 1981 McLaren has never built a car without a carbon chassis.
On the 12C and 12C Spider, aluminium extrusions and castings are jig welded onto front and rear structures and bolted directly to the MonoCell. Along with the carbon MonoCell, they carry the lightweight composite body panels. Apart from the roof, and the engine cover, body panels are identical to the 12C. A redesigned glass engine cover maintains an unobstructed view of the handsome twin turbo V8 engine.
‘The front and rear aluminium structures are easy to repair,’ adds Patterson. ‘They absorb impacts and can be replaced easily. Cars with full aluminium chassis use their structure to absorb and crumple on impact, causing more damage and expense to the whole structure, including the passenger cell.’
UNIQUE AIRBRAKE PROVIDES ACTIVE AERODYNAMICS
As with the 12C, the 12C Spider is fitted with the unique McLaren Airbrake – an ‘active’ rear wing that increases its angle to boost downforce and improve stopping power and stability through corners. ‘As with every other aspect of the car, we have “added lightness”,’ notes McLaren Automotive Chief Test Driver, Chris Goodwin. ‘Under heavy braking above 95 km/h, a piston operated by the transmission hydraulics raises the Airbrake to 32 degrees. Once this wing angle is set, and the Airbrake is pushed into the airflow, the centre of aerodynamic pressure forces the bottom of the wing up to 69 degrees. With the use of clever aerodynamics, rather than a bigger, heavier motor, the wing is deployed to its full and maximum angle. This weight-saving thinking has reduced the weight of the mechanism by 50 per cent.’
The ‘active’ aerodynamics of the McLaren Airbrake is another Formula 1™-derived innovation – although now banned, as it conferred a substantial performance advantage.
The total weight of the new 12C Spider is 1,474 kg, an increase of only 40 kg on the 12C, less than any other car in the class. The increase is because of the added weight of the Retractable Hard Top and other small changes, including a slightly heavier (by 2 kg) exhaust system. Overall, the 12C Spider is substantially lighter than most comparable convertibles, as well as being stronger and stiffer.