Until recently, carbon was considered a second-rate material when it came to manufacturing cars. Benefits lay in its weight – it’s light and flexible – but the substance lacked strength in comparison with steel and aluminum, and it was prone to breaking under pressure. Recent technological advances have turned that widely held view on its head.
Carbon is still light, but it is now also sturdy, rigid and reliable under high pressure. So much so that Lexus has begun to use the material in a variety of applications, notably in a package of carbon fiber parts fitted to the brand’s new coupe, the RC F. Here we explore the parts (the engine hood, the roof and the rear spoiler), the material from which they’re made, and the technology that has enabled them.[image_frame style=”framed_shadow” align=”center” alt=”Lexus RC F” title=”Lexus has begun to use carbon in a variety of applications, notably in a comprehensive package of carbon fiber parts fitted to the brand’s new coupe, the RC F” height=”385″ width=”640″]https://www.car-engineer.com/wp-content/uploads/2015/01/Lexus-RC-F-carbon.jpg[/image_frame]
Benefits of using carbon
Each part of the carbon package – the engine hood, the roof and the rear spoiler – makes a difference in vehicle performance. Using carbon in exterior body panels lowers the car’s total weight, which in turn lowers its center of gravity. That means tires can better grip a road’s surface, especially when cornering, making it resistant to sideways g-force.
Carbon makes a difference on the inside, too: chassis and cabin sections formed of the material can increase a vehicle’s rigidity. That’s why Lexus engineers opted to use carbon to construct the body frame of the LFA, the brand’s two-seater supercar, and why they’ve extended use of the material here, in the RC F package.
Carbon package elements
The surfaces of the carbon package elements feature intricate patterns formed when a multitude of carbon fibers are woven together diagonally – a pattern typical of carbon parts – giving the RC F a sporty appearance. Examine a unit of carbon under a microscope and you’ll find the material to be an extremely fine acrylic fiber measuring only several micrometers in diameter. Depending on the strength of the material required, anywhere between 3,000 and 24,000 of these fine threads are bundled together to form a tow, and numerous tows are woven into a carbon fabric, similar to a yarn.[image_frame style=”framed_shadow” align=”center” alt=”RC F carbon hood” title=”The surfaces of the carbon package elements feature intricate patterns formed when a multitude of carbon fibers are woven together diagonally” height=”540″ width=”640″]https://www.car-engineer.com/wp-content/uploads/2015/01/RC-F-carbon-hood.jpg[/image_frame]
How the parts are made
The engine hood and the roof are formed from four 0.5-millimeter-thick carbon sheets machine-pressed together at 140 degrees Celsius. The rear spoiler consists of two different materials, carbon and fiberglass, and becomes beneficial when the car exceeds 50 mph. At this speed the spoiler automatically extends upwards, giving the wheels more traction on the road. It may be extended manually at any speed. “Technological advances have made carbon less expensive to purchase than before,” says Ryoichi Ishikawa, project manager of the Lexus Sports Vehicle Management Division. “But it’s still expensive, and we can only use it for vehicles in the upper echelons of the lineup. Our ultimate goal is to further develop our technology to make carbon parts inexpensive enough to use in entry models. In my view, carbon, which is now five to six times stronger than steel, is a material of the future.”