One of the dustiest clichés in the world of supercars is to say that a certain model is a "race car for the road". Nevertheless, the technical details of the MP4-12C demonstrate that McLaren has given us just that. Each and every technical area of the car comes with motorsport-inspired solutions that set the MP4-12C apart in the world of supercars.
Body and Chassis
The core of the McLaren MP4-12C is a carbon fiber tub called MonoCell, which reduces weight and thus increases performance in all areas. In addition to this, the carbon core of the supercar also increases rigidity, bringing benefits on both the handling and safety fronts.
McLaren pioneered carbon fiber construction in Formula one back in 1981, with the MP4/1 F1 racer, while the McLaren F1 was the first road car to use the wonder material. Carbon fiber was also featured in the Mercedes-Benz SLR McLaren.
However, the construction techniques for the aforementioned vehicles required thousands and, later on, hundreds of man-hours which pushed the costs to an astonishing level. For the MP4-12C, McLaren uses a carbon fiber composite technology, with one-piece moulding. This reduces the production process duration to just four hours.
The result of using Resin Transfer Moulding production is the hollow one-piece MonoCell, which tips the scales at just 165 lbs (75 kg). The suspension system of the vehicle is directly mounted to the carbon structure. The strong torsional rigidity of the MonoCell also means that the suspension doesn't need to use settings that make a compromise in order to deal with the flexing of the car.
The McLaren MP4-12C uses front and rear aluminum structures - the castings and extrusions are jig welded into the completed structure, being bolted to the MonoCell. The one up front is there for safety purposes, while the rear one supports the engine and the suspension. In addition to that, the windscreen frame is made of aluminum casting and features baron steel tubes for added resistance.
The supercar uses composite body panels, some of which are placed on the car using custom adhesives. Thus, the panels are both lightweight and cost-effective, but the story also has a dark side. The front fenders, bonnet and roof are built from aluminum, while most of what’s left of the MP4-12C’s body is made from glass fiber composites - Sheet Molding Compound (SMC) as McLaren calls it.
SMC is lighter than aluminum, but it doesn’t match the metal’s strict tolerance level. This means that the SMC’s perceived quality of the panels and gaps is lower than that of aluminum - McLaren has decided to trade off some of the visual effects for extra lightness.
Placing the McLaren MP4-12C and the Ferrari 458
on the scales would show a difference of about 110 lbs (50 kg) in favor of the British model - this is before ticking the lightweight option of the latter, which saves an extra 77 lbs (35 kg). As for the weight distribution of the McLaren MP4-12C, this sits at 42.5:57.5. This is 0.5 percent closer to the ideal one when compared to that of the 458 Italia.
In addition to that, McLaren claims that the MP4-12C offers a superior torsional rigidity and polar moment of inertia - the latter means that more of the mass is concentrated closer to the car’s center of gravity and has a crucial influence on the cornering turn-in.
McLaren's first road car, the record-breaking F1, was motivated by a V12 engine supplied by BMW. Since almost a decade separates the F1 and the MP4-12C, McLaren has now fitted the car with a downsized engine.
We are talking about the M838T, a 3,799cc V8 unit that features twin-turbocharging and dual variable valve timing. The powerplant delivers 600 hp at 7,000 rpm and a peak torque of 443 lb-ft (600 Nm), available between 3,000 and 7,000 rpm.
In addition to that, 80 percent of the aforementioned torque is delivered starting from 2,000 rpm. From the 2013 model year onwards, the unit's output has been increased to 625 hp at 7,500 rpm. This power upgrade is offered alongside a few other refinements as part of a complimentary upgrade pack for owners of the pre-update model.
Since McLaren has never built its own engines, neither for the road, nor for the track, this time it turned to British automotive supplier Ricardo for the development of the V8 unit. The powerplant also incorporates some of the lessons learned from the Nissan VRH35 endurance racing V8 unit, for which McLaren had acquired the rights to.
McLaren brags that the M838T offers the highest hp to CO2 emission ratio of all cars currently in production, including petrol, diesel and hybrid powertrains. The unit emits 279 grams of CO2 per km, compared to the 307 g/km of the Ferrari 458 Italia’s 570 hp naturally-aspirated 4.5-liter V8. Thus, it seems to be handling emissions just fine, despite not making use of direct injection.
The British V8 features dry sump lubrication and a flat plane crankshaft, which reduce its height, allowing it to be mounted low in the MP4-12C's chassis.
Like the rest of the car, the engine features weight-saving technologies, including composite cam covers and intake manifolds, as well as aluminum cylinder liners that use a Nikasil coating. With the same aim in mind, the traditional silencer box in the exhaust has been replaced with a mixing box. Up to this structure, the exhaust features sandwich layer heat shields. The result is pretty impressive, as the exhaust gas temperature is brought from 1,650 degrees Fahrenheit (900 degrees Celsius) to 1,650 degrees Fahrenheit (300 degrees Celsius) in a 0.7-inch (18 mm) area of the engine compartment.
Continuing to move along the power flow, we find a seven-speed dual wet clutch transmission coming from Graziano - the Italian supplier is a favorite child of the supercar world, which also makes the Lamborghini Aventador's ISR single-clutch automated manual, for example.
For McLaren, Gratziano has developed a Sequential Shift Gearbox (SSG) that comes with an unique feature called pre-coq. This means that the rocker used to change gears has two positions, like the trigger of a rifle. The first one can be used to tell the transmission to engage the following gear and prepare the oncoming clutch. Once the driver fully pulls the paddle, the shift takes place significantly faster than in a conventional double-clutch gearbox.
We've been used to find limited slip differentials in any high-power rear-wheel drive car that takes performance driving seriously, but the MP4-12C features an open diff. That's because McLaren decided to reduce weight by replacing the LSD with a system of its own.
The British supercar mixes the ESP with a function called Brake Steer in order to control lateral vehicle dynamics. Brake Steer draws inspiration from a similar system used on the McLaren 1997 MP4/12 Formula 1 car. The system monitors the steering angle in order to determine the line chosen by the driver and can brake the inside wheel during a corner entry, all in order to reduce understeer. Brake Steer can also be used to deal with oversteer, as the system can brake the inside rear wheel if this is spinning under corner-exit acceleration.
In its hate for vehicle mass, McLaren has eliminated the anti-roll bars, a feature present on any road car since as long as we can remember. To replace these, the MP4-12C uses a system called Proactive Chassis Control. This links the four adaptive dampers of the car, relying on the same pump that serves the electro-hydraulic power steering.
The system constantly adjusts the pressure in each shock absorber, based on the road conditions, as well as on the driver's preferences. The latter are read using a switch on the center console, which offers three settings: normal, sport and track.
The rest of the suspension consists of double wishbones and coil springs for both axles.
The standard cast alloy wheels come in a size of 19-inch for the front axle and 20-inch for the rear one, with McLaren bragging it has whipped engineers to cut an extra 9 lbs (4 kg) off the rims. In addition to that, McLaren has worked together with Pirelli to develop dedicated tires for the MP4-12C.
The McLaren MP4-12C manages to make fun of the optional Brembo carbon-ceramic brakes it offers - the standard stopping hardware it packs is lighter than the optional ceramic one. The AP brakes of the British supercar feature forged aluminum bells, which allow them to save 18 lbs (8 kg) compared to a conventional system.Continue reading
MCLAREN MP4-12C technical data summary
Engine: 3799 cm3 cc V8 Petrol
Transmission: dual-clutch SSG with Pre-Cog
Dimensions: 177.4 in OR 4506 mm length / 75.2 in OR 1910 mm width / 47.2 in OR 1199 mm height
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