When you watch an F1 fly down the Hangar Straight at Silverstone, you’re watching an F1 engineer’s appreciation of art. The exhaust, gear casings, and even the gear box, are all examples of great material selection for a given design and purpose. Modern day formula one engineering would have baffled F1 engineers during the sport’s early decades.
In the 1950’s and 60’s F1 engineering was close to road car engineering as F1 cars had steel tubular frame construction, aluminum body panels and cast iron engine blocks. These cars for very heavy even by today’s standards, weighing around 600 kg. An engineering breakthrough was made when McLaren introduced the first carbon fiber monocoque chassis, the MP4/1, in 1981. This allowed all the teams to make car structures more optimized for strength and far less weight than aluminum. This weight loss was around 50 kg and the new weight distribution on the chassis allowed engineers to optimize the car’s performance.
The development of today’s carbon fibre monocoques are a pure engineering marvel. Each survival cell weighs a mere 35-40kg and must endure a wide variety of forces in order to protect the driver throughout all crash scenarios. This is achieved by teams laying up hundreds of sheets of carbon fibre where each sheet is oriented in a particular way to endure a particular type of crash and stress. The strength to weight ratio is part of the reason why it is being used. More importantly for the teams, it doesn’t fatigue like metals so they are able to push components harder without the fear of developing cracks.
That being said, carbon fibre components are not a universal solution. In suspension components for example, aluminium alloys are still the material of choice. In engineering terms, wishbones and pushrods must be stiff under load, but in normal terms, they also need to be a bit flexible to absorb kerb strikes and impacts. Carbon fibre certainly provides balance, however, it is also easy to machine and inspect for damage. It is not easy to visually scan a carbon fibre component for internal cracks after an impact, but aluminium visually indicates inspects and breaks. Throughout the limited time of a race weekend, these practical advantages are just as critical as a weight saving.
Now let’s tackle the challenges presented by the exhaust system. In an F1 engine, the exhaust gases can reach temperatures over 1000 °C, and regulations state that exhausts must be designed to handle much higher temperatures. For that reason, titanium has become the preferred material. It is strong at extreme temperatures and weighs about half of what stainless steel would. Each team employs different titanium alloys at various parts of the exhaust. They use different grades of titanium based on the temperature and mechanical stress each part will experience. Close to the engine, the titanium may be a high temperature grade that is strong up to 900 °C, while farther down the exhaust, lighter alloys may be used.
Another example of a material trade off is the gearbox casings. F1 gearboxes are made using magnesium castings because of their great weight to rigidity ratio. Magnesium is 35 % lighter than aluminium, which is significant when mass centralization and lowering the car’s center of gravity is a goal. The gearbox casing has to be rigid enough to keep the gear shafts perfectly aligned as they shift. The load produced from shifting gears is enormous, and any flex in the casing can cause the gears to mesh imperfectly, which results in increased wear and possible failure.
Designing a race car is a complex balance of performance, weight, and cost. Components of a race car are manufactured from different materials. Engineered tools simulate and map the distribution of loads, helping engineers decide the optimal configurations and materials to strengthen and lighten race car designs. Thermal expansion is also a concern due to varying sizes of materials. Bolting a race car’s components together runs the risk of them either seizing or moving out of position due to temperature changes during a race and the expansion of different materials.
Race car components are also subject to different manufacturing processes. Skilled technicians must hand lay certain components that are manufactured using carbon fiber into expensive molds. In contrast, the means to manufacture components that are made from machined aluminum can be done a lot faster and design changes can be done to modify them much easier. When a team is able to identify performance gains, the speed of a manufacturing process becomes much more valuable in contrast to the weight of the components.
F1’s materials are still evolving and will continue to do so. In the course of a single racing season, teams undergo minor changes that compound to large performance changes. Frequent regulation changes and performance shifts lead to ongoing new carbon fiber styles, improved aluminum alloys, and cutting-edge hybrid materials in the motorsport industry. In racing, the materials utilized are just as important as the drivers that are hired by the team.
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