Thursday, October 22, 2009

Lexus LFA



The new Lexus LFA marks an important moment in both the history of Lexus and the development of the supercar. A true "clean-sheet" design, the Lexus LFA was created by a small, passionate and dedicated team of engineers whose achievement has been to push the boundaries of technologies materials and engineering at every stage to produce a car like no other to have carried the Lexus badge.

Constructed using advanced carbon fibre technology, the rear-wheel drive Lexus LFA is powered by a bespoke, high-revving 552bhp 4.8-litre naturally aspirated V10 engine, matched to a rear-mounted six-speed sequential automatic transmission, giving 200mph-plus performance.

In the words of Chief Engineer Haruhiko Tanahashi: "The Lexus LFA is a thoroughbred supercar, a machine engineered to achieve a single goal - to deliver a supreme driving experience. Over the past decade we have pushed every boundary in pursuit of this goal and I believe we have created the most driver-orientated car we possibly could."

CARBON FIBRE CONSTRUCTION

Keeping the car's weight to an absolute minimum was one of the defining elements in the development of the Lexus LFA and this led to the decision to switch from using aluminium for the car's construction to advanced Carbon Fibre Reinforced Plastic (CFRP) for the chassis and bodywork.

Moreover, Lexus decided the CFRP structure should be built in-house rather than by a third-party supplier. In doing so, it drew on Toyota Motor Corporation's heritage in textile weaving technology to push the boundaries of its technical abilities, developing new carbon fibre looms and a laser system for monitoring the integrity of the material.At four times the strength of aluminium, CFRP gives the Lexus LFA an exceptionally stiff and strong structure, and also delivers major weight advantages, saving around 100kg on an equivalent aluminium body. CFRP accounts for 65 per cent of the body-in-white, with aluminium alloy used for the remaining 35 per cent.

Unlike the few other vehicles on the market that use CFRP construction, the Lexus LFA uses the same advanced resin technology favoured by cutting-edge aerospace programmes for its unmatched weight and strength properties.

ENGINE

The heart of the Lexus LFA is a bespoke, naturally aspirated V10 engine that sets new standards for compact dimensions, lightweight architecture and scintillating performance. From the outset it was determined the engine should have a 4,805cc capacity, develop 552bhp and rev to a wailing 9,000rpm red line. A 72-degree angle between the cylinder heads is ideal for achieving balance in the engine for exceptionally smooth running, while providing individual, electronically controlled throttle bodies for each cylinder gives excellent throttle response.

Using a dry sump lubrication system allows the block to be positioned deep in the engine bay, lowering the car's centre of gravity and moment of inertia, and enabling the engine to handle sustained, high-speed cornering.

The V10 produces 480Nm of torque at 6,800rpm, 90 per cent of which is available from 3,700rpm all the way to the 9,000rpm red line, thanks to Dual VVT-i technology, equal length exhaust manifolds and high-volume, 12-hole fuel injectors. This gives searing in-hear acceleration at all engine speeds and in any gear: nought to 62mph takes just 3.7 seconds and maximum speed is 202mph.

With a kerb weight of 1,480kg, the Lexus LFA has a power to weight ratio of 373bhp per tonne, while specific output of 115bhp per litre is among the highest of any current supercar, aided by a high, 12:1 compression ratio, low friction internals and optimised intake and exhaust flow.

In spite of its potency, the V10 is an object lesson in compact and lightweight packaging, being about the same size as a regular V8 engine and weighing about as much as conventional V6. It is also as reliable and refined as any other Lexus power plan and exceeds Euro 5 emissions standards.

The engine was developed in conjunction with Yamaha through the established collaborative partnership between Toyota Motor Corporation and the Japanese specialist engineering company.

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