September 2, 2019. 304.773 Miles Per Hour. 490.484 Kilometers Per Hour. A Worldwide Statement. Bespoke French automaker, Bugatti, has broken yet another top speed record, only this time it has broken all limits. The car is specific was based on the “regular” Chiron, the company’s $3M hypercar, and modified with the help of Italian race car manufacturer, Dallara. Topped off with new center stacked exhausts, a fixed wing, roll cage, a swooping rear end with an extra 10 inches of length, and 99 horsepower, it is officially the world’s fastest production car, beating the previous record-holder, the Koenigsegg Agera RS. However, the real MVP of this story is something that some of us overlook, the tires.
You see, all of these technical specifications and add-ons sound great, but wouldn’t an automaker have done this by now. The problem is that there were not strong enough tires, until now. In order to understand, you must understand the physics of rotational energy. Under high speeds, tires heat up and expand, putting more pressure on the tires. On standard road cars, tires may reach up to 160 °F, however, in racing, these tires often reach over 300 °F. This heat causes air molecules in a tire to move faster, hitting the inner wall of the tires more often. This creates pressure and with a curb weight of over 4,000 pounds, this extra pressure is very significant, causing tires to warp out of shape and blowout if they are not strong enough. The following video explains it well:
As a result, American tire maker Michelin had to create an extremely rigid and composed tire to handle the strenuous forces. To do this, they reinforced a set of tires with steel belts and carbon fiber on the tire carcass to hold the rubber together, having each one tested at 318 mph and specially x-rayed by engineers to ensure the strength and capability of the tire. They held up, and the rest is history.
Sources:
- https://www.wired.com/story/bugatti-chiron-speed-record-305-mph/
- https://www.matfoundrygroup.com/News%20and%20Blog/What_Happens_at_300mph
- https://www.motorauthority.com/news/1109205_why-cant-production-cars-reach-300-mph
- https://www.aceable.com/blog/this-is-what-happens-when-tires-get-too-hot
- https://www.caranddriver.com/news/a28927762/bugatti-chiron-super-sport-300-photos-info/
- https://www.thedrive.com/news/29854/record-setting-bugatti-chiron-used-michelin-tires-with-carbon-fiber-during-300-mph-run
