Aug 8

Aug 8 Guide: 12C Surrealism - a Historical & Technical Appraisal of the McLaren X-1

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Background

At the Quail Motorsports Gathering in August 2012, McLaren unveiled a one-off special bodied MP4 12C dubbed the X-1.

Created at the request of a secretive VIP customer from Bahrain (most likely an individual connected to the country’s sovereign wealth fund Mumtalakat Holding Company that took a controlling interest in the Woking firm during 2007), the X-1 was a demonstration of just what could be achieved by the McLaren Special Operations department given a suitable budget.

This latest machine was in actual fact not the first time that McLaren had constructed a car referred to as X-1. That honour went to a unique Ford GT40-based Roadster commissioned back in late 1965. Back then the company (known as Bruce McLaren Motor Racing) was being run out of a comparatively tiny factory in Feltham, Middlesex.

The McLaren-built Ford X1 was based around an experimental GT40 tub uniquely fashioned from aluminium instead of steel. It also featured a hitherto unseen cut-down body, a special Hewland gearbox and weighed 250kg less than a conventional GT40 Mk2 Prototype. Chris Amon did a handful of late season races in the X1 Roadster before it was converted to a more conventional appearance for 1966 when Ken Miles and Lloyd Ruby drove it to victory in that year’s Sebring 12 Hours.

By contrast, the 2012 MP4 12C-based X-1 was a bespoke styling exercise for a customer with practically unlimited funds who wanted a machine constructed entirely to his personal requirements.

The result was one of the most extraordinary looking supercars of its era and something truly individual.

Bodywork

Apart from the windscreen and door glass, practically every aspect of the X-1’s body was completely redesigned compared to the standard MP4 12C. Inspiration was taken from an array of the client’s favourite 1950s and 60’s styling concepts by Mercedes-Benz, Facel Vega, Citroen, Buick and Chrysler.

Up front, curvaceous new headlight clusters were neatly integrated with a plunging hood and gaping primary air intake. Intricately detailed brake ducts were located on either side of the front apron, outboard of which were natural aluminum trim sections. This brightwork swept rearwards all the way to the back of the car to give a distinctive pontoon effect along each flank with the rear wheels partially shrouded from view.

A jutting swage line featured a natural aluminium trim panel with rear wheel vents. Access to the concealed rear wheels was made possible by electro-hydraulic panels that moved outwards and upwards at the touch of a button.

The rear section of the cockpit featured new sail panels that curved inwards to give a classic flying buttress effect. A curved, near vertical rear screen was adopted instead of the MP4 12C’s fastback arrangement.

All new cooling solutions were integrated on the flattened engine cover, behind which was a re-profiled airbrake that improved stopping performance and stability. As per the standard MP4 12C, under heavy braking above 95kmh the airbrake activated at a 32° angle. Once the first stage angle was set, the centre of aerodynamic pressure forced the bottom of the airbrake up to 69°.

The X-1’s tail fascia incorporated the MP4 12C’s familiar high level dual exhausts, but the rest of the back end was completely new. Huge meshed vents were incorporated either sides of the exhausts with a third grille located in between and above the natural aluminium licence plate plinth. Complex tail light clusters spanned almost the entire height of the tail fascia.

As per the customer’s request, McLaren finished the X-1 in a combination of metallic black paint and exposed carbonfibre that gave excellent contrast against the car’s natural aluminium detailing.

Interior

Inside, all the MP4 12C’s usual fixtures and fitting remained although the upholstery featured custom-trimmed deep red leather zones for the roof, cockpit pillars, upper door panels, outer dash area and upper section of the central divider. The seats were finished to match. The rest of the cockpit was a mixture of dark grey leather with matching alcantara and carpet plus plenty of exposed carbonfibre.

As per the regular MP4 12C, bucket seats (electrically adjustable for height) were positioned close together to improve weight distribution and avoid any pedal clearance problems from wheel well intrusion.

The dash was integrated with a slim centre console that gave a wraparound effect for the occupants.

Behind the three-spoke steering wheel was a large analogue tachometer inset with a digital speedometer. Off to the left was an illustrated warning display and to the right were digital read outs for temperatures and levels. At the extremities of each side were an array of individual warning lights.

The forward section of the slim centre console housed a 7-inch IRIS touch screen and rotary control knob. Underneath was a control panel with the rest of the switchgear. Additional control panels were located on each of the doors.

As you would expect, the X-1 came with a long list of equipment to include a high end audio system, keyless entry, keyless start, dual zone air-conditioning, rain-sensing wipers and cruise control.

Chassis

Aside from its custom Pirelli P Zero-shod diamond cut wheels, the X-1’s underpinnings were pure MP4 12C.

The single piece carbonfibre monocoque (dubbed Carbon MonoCell) weighed just 80kg and was manufactured by Carbo Tech in Salzburg. Attached to either end were aluminium subframes to carry the engine, suspension and ancillary equipment.

The wheelbase measured 2670mm.

Conventional coil sprung double wishbone suspension worked in conjunction with a state-of-the-art ProActive Chassis Control system that did away with the need for traditional dampers and anti-roll bars. Instead, interconnected electro-hydraulic dampers had their pressure rates continually adjusted to control pitch and roll. This gave a soft compliant ride at lower speeds which then firmed up under fast driving conditions.

A Handling button on the centre console allowed the driver to choose one of three damper modes: Normal, Sport and Track.

An Electronic Stability Control system was also installed along with electro-hydraulic variable rate power steering.

The X-1 ran McLaren’s normally optional Brembo carbon ceramic brake pack with 394mm discs and 6-piston calipers up front and 380mm discs with 4-piston calipers at the rear

A standard 72-litre fuel tank was installed between the cockpit and engine.

Engine / Gearbox

In the engine bay was McLaren’s longitudinally-mounted Type M838T twin turbocharged 90° flat crank V8 developed in collaboration with Ilmor and Ricardo. It had an all-alloy construction, dry-sump lubrication, dual overhead camshafts per bank and four valves per cylinder. The extremely fuel efficient motor also employed state-of-the-art variable valve timing.

Displacement was 3799cc thanks to a bore and stroke of 93mm and 69.9mm respectively.

Engine management was courtesy of a Bosch-supplied ME17.8.3 system. The charge air cooler, condenser and radiators came from Visteon.

Engines were built for McLaren by Ricardo in Shoreham.

With an 8.7:1 compression ratio, peak output was 592bhp at 7000rpm and 443lb-ft between 3000rpm and 6500rpm. 80% of the peak torque was available from just 2000rpm.

Hooked up to the engine was a seven-speed paddle-shift gearbox with dual clutch transmission which also offered a fully automatic mode.

The Seamless Shift Gearbox (SSG) was manufactured by Graziono Transmissioni in Turin. It featured a pre-cog system that pre-loaded the clutch allowing virtually instantaneous gear changes.

Alongside the Handling button on the centre console was a Powertrain button which offered Normal, Sport and Track modes which varied gear shift speeds.

The open differential used an F1-style brake steer system where the inside rear wheel braked during fast cornering to reduce understeer (effectively brake-based torque vectoring).

The aforementioned traction control system offered a choice of four stability modes: Winter, Normal, Sport and Track.

A launch control function was also installed.

Weight / Performance

McLaren never published either weight of performance figures for the X-1.

However, it probably tipped the scales fairly close to the 1336kg original and offered a broadly simiar level of performance (218mph top speed and 0-62mph time of 3.3 seconds).