Their sweet smiles are misleading. Sure, Kaitlinn and Kirstin Simmons are polite young ladies … off the race track.

On the track, though, that’s a different story. They are up-on-the-wheel, take-no-prisoners weekly racers. The perfect example was their most recent race. They were both involved in a first-lap spin in the feisty Hornet Division at South Boston Speedway. They tightened their belts under caution and fought their way back toward the front. Kaitlinn wound up third, Kirstin fifth.

They both race beyond their age and experience. Kaitlinn is 20; Kirstin 15. This is the first season for both in stock cars. And it’s not like racing has all of their attention either. Kaitlinn is studying to be a dental hygienist at Halifax Community College in Weldon, NC. Kirstin is a sophomore at Park View Senior High School in South Hill.

But when the lights come at South Boston on Saturday nights, the daughters of Sammy and Kim Simmons are all about racing.

“Racing is my passion,” said Kirstin.

They sort of have racing in their blood. Dad Sammy raced on the dirt at Clary’s Speedway in Brinkleyville, NC. By the time the girls were teenagers, they not only were winning races, but championships. Kirstin is a two-time Virginia state kart champion and finished runner-up in the national chase when she was 13.

“I want to move up and make a career out of racing,” said Kirstin. “Go-karts could no longer do that for me.”

For Kaitlinn, racing is more of a hobby than for her sister.

“I’d like to move up, but this is a release from (dental hygienist) school. And it’s a family thing for us,” Kaitlinn said.

Kirstin made her South Boston stock car debut late last season. She was the typical raw rookie. “I had to start at the rear of the field because I’d never shifted (gears) before,” she said. But her talent was obvious. She finished third in her debut, and after the top-two finishers were disqualified, she took the winner’s trophy home.

This summer has been an education for the sisters, but they have been good students in the Hornet Division, an entry-level class for front-wheel drive cars. The only upgrades to the cars are the safety features required.

But they are bigger and heavier than go-karts and that upped the learning curve.

“I think I’ve come a long way,” said Kaitlinn. “The biggest thing I’ve learned is about the drivers around you. How they drive.”

“The biggest thing I’ve learned is with passing,” said Kirstin. “In karts you could dive-bomb somebody. You just can’t do that in these.”

The sisters, who drive identical black cars with appropriate pink numbers, Kaitlinn in the No 3, Kirstin in the No. 4, have quickly become fan favorites. At a recent fan appreciation event on South Boston’s front stretch, they drew as many autograph seekers as any of the Late Model drivers.

“I think everyone is surprised at two sisters running together,” said Kaitinn, who received a text recently from the parent of a young girl who recently attended her first race and became a fan because of the sisters.

They say there is no sisterly rivalry on the track, though they admit they have made contact before.

“There have been a couple of run-ins” between them, Kaitlinn said.

Kirstin explained “One time it kind of happened when I went to pass her.”

They both have been well-accepted by fellow drivers, even though there may be a couple who aren’t too excited racing against them. But that doesn’t really bother the Simmons sisters.

“Just because we’re girls, they know we’re not going to back off,” said Kaitlinn.

NASCAR racing will return to South Boston Speedway on Saturday for the 7 p.m. running of the GCR Presents Spaulding Equipment Late Model Twin 75’s racing program.