This is piston No. B0311UB rev NC (“B03”, for short). It is toast. In a hellish moment, piston B03 heated itself up to more than 750 degrees F under pressures exceeding 3600 psi, and it failed—disastrously.

B03 was previously installed in engine No. 5005, a 2.2-liter turbodiesel which had then been installed in car No. 70, a 2013 Grand Am GX-class Mazda 6. Things went terribly wrong with Sylvain Tremblay at the wheel during the 2013 24 Hours of Daytona, but that was just the beginning of the story. Mazda isn’t taking the easy way out in its return to top-tier racing. Failure begets progress. A single mangled part, a scarred piston about the size of an average man’s fist, started a process of analysis and development that shows not only the intensely hard work it take to win, but why manufacturers go racing at all. Read the whole thing over at Road & Track.

Image: Josh Scott