The teenagers stood in the Kellenberg Memorial High School gym, fiddling with the little blue propeller car they spent months perfecting.
They anxiously checked a stopwatch between adjustments at Saturday's Western Long Island Regional Science Olympiad.
Dan Charytonowicz, 18, and his partner, Ken Peluso, 15, both students at Wantagh High School, had a few minutes until the end of prep time -- when their car, built for speed, would have to pull a sled along a magnetic levitation track.
"He has a lot riding on it because last year was not good," said Sal Mule, Charytonowicz's middle school science teacher and mentor.
Last year, Charytonowicz's vehicle didn't make it down the track. But when the stopwatch chimed Saturday, the senior's car sailed.
"It went great," Charytonowicz said afterward, as color returned to his face. "[The judge] just said we got the fastest time right now, so I'm pretty excited."
Students from 38 Nassau County high schools participated in the event.
Some stood by as the strength of their handcrafted balsa wood towers was weight-tested.
Others sent homemade vehicles down ramps, hoping hours of calculations meant they would stop at a mark roughly 10 feet away.
In the school's labs, still other students donned goggles and aprons for forensics exams, or identified rocks, minerals, fossils and trees.
In his second year competing, Charytonowicz said he looks forward to coming to Kellenberg, which hosts the regional event every year and had a two-year winning streak on the line.
The private Catholic school in Uniondale has placed fifth or higher since 1997, and former parents and alumni frequently attend the regionals.
"Science Olympiad kind of showed me what I wanted to do with my life," said Barrick, 19, who is studying materials science and engineering. "It's so important to me that you give back to something you love so much."
But it demands dedication, Barrick said. In high school, she spent months studying thick binders of information on fossils she had compiled.
"When you prep for something for so long you just want to make sure everything goes right," Charytonowicz said.
Eight of the 72 teams competing Saturday will earn trophies and advance to the state competition in Buffalo, where 54 teams will compete next month.