Two Rock Falls sisters squared off in the Young Gun heat at the Ogle County Fair’s demolition derby on Saturday night.

But for Abby and Aubree Boss, the competition meant much more than just a chance to win a trophy.

“I do it for my uncle who passed away,” said Abby, 17. “He was my dad’s brother.”

Abby, who is entering her senior year at Rock Falls High School, had “#82″ on the side of her demo car as a tribute to Brock Boss, her late uncle, and brother to Brick Boss, Abby’s dad.

“That was [Brock’s] number,” Abby said after climbing out of her 1993 Lincoln demo car.

Abby drove her battered Lincoln to a fourth-place finish, one place behind her 12-year-old sister, Aubree, who said she was competing for her late uncle, Steven M. “Bubba” Cochran, the brother of Abby and Aubree’s mom, Tonya. He died July 24.

“I wasn’t going to drive, and then I decided to do it for Bubba,” said Aubree, who will be a seventh grader in the Montmorency School District.

Aubree’s co-pilot was her dad, Brick, while Abby’s friend Travis was along for the ride.

Aubree finished third after battling two other cars in the final minutes of the opening heat of the night.

With the bleachers filled to capacity, track officials for Robbo’s Extreme Derby Promotions LLC waved the green flag for the first heat of several planned for the evening.

The four cars crashed and crumped their way around the track until one was left running.

“You could tell the other two were working together, so we had to stick it out,” Brick said after the race.

Saturday night’s race was not the first for either girl, with both sitting behind the driver’s seat a couple of other times.

“Last time I was second,” said Abby. “I like the adrenaline rush.”

For Aubree, the competition is cathartic. “I can let my anger out on other people,” Aubree said, smiling.

Both drove 1993 Lincolns in Saturday’s race. Their numbers – 690 and 790 – mirrored their dad’s 590 when he races.

“We help build the cars,” said Abby. “We have a Dixon address, but we build the cars in Rock Falls.”

Abby said she enjoys the competition the derby brings. “People just need to quit making demo derbies about ‘bad blood,’” she said. “It should not be about that. It should be about having fun.”

So, what does Abby drive when she’s not on the demo track? “Uh, what is it that I drive?” she asked her mom. “Oh yeah, a Chevy Impala.”