The hydrogen Nascar circuit may yet be a few years off, but in a warehouse in Philadelphia Sunday, the simple chemical reaction of H2 + O2 kicked the crap out of the competition in this year’s Chem-e-Car race. The event tasks teams of college students to build RC-size cars that can carry one cup of water 60 feet, fueled only by a chemical reaction. It’s sponsored, appropriately, by the American Institute of Chemical Engineers.

The winning team, from Cornell, used a fuel cell to generate DC current that powered a Lego motor. Other fuels this year included candy sours (citric acid), beetle liver (catalase enzyme), and fire starters (magnesium). The race’s twist is that the car must also stop using a chemical reaction, and the closer to the finish line it stops, the better. The Cornell team is the first in history whose vehicle stopped directly on the finish line with a braking system made from an Iodine solution and a light sensor. When the solution turns dark, the light sensor triggers a circuit switch so that the power that had been driving the motor instead lights an LED.

Second place went to Louisiana State University for the above-mentioned citric acid engine, and the Texas A&M took third with a combo of sodium carbonate and hydrochloric acid.