Stock-car racing’s traveling circus drops anchor in Darlington this week, and a smorgasbord of juicy subplots spice the main event, Saturday night’s Bojangles’ Southern 500.

Fans might wonder if there will be a renewal of the Kevin Harvick-Kyle Busch donnybrook at the finish of the 2011 race or if Dale Earnhardt Jr. can end his long victory drought.

Many of the 60,000 or more who fill Darlington Raceway will focus on Danica Patrick, who wants to use the week for a steppingstone toward success in stock-car racing’s top level.

Following Janet Guthrie (1977) and Shawna Robinson (2002), Patrick will become the third woman to start a Sprint Cup race at Darlington. Her credentials include third- and fourth-place finishes in the Indianapolis 500, and she has long-term ambitions for stock-car racing success.

“She’s a race-car driver,” Denny Hamlin, one of stock-car’s brightest stars said in delivering the ultimate compliment from one competitor to another.

But stock cars and Indy cars have little in common and making the adjustment has been a challenge for her. After 33 races on NASCAR’s Nationwide Series spaced over three seasons, Patrick is testing her mettle in the upper echelon this season. She plans to run 10 Sprint Cup races for Stewart-Haas Racing in this year’s get-acquainted tour, and she will drive a full Sprint Cup schedule in 2013.

The team made sure the learning curve would be steep by including Darlington on her schedule.

“I have kind of thrown her to the wolves with the schedule,” car owner and Sprint Cup champion Tony Stewart said. “We didn’t pick easy races. . . . At the end of the year, she may not like me very much, but I think by midway through 2013, she’s going to understand why we picked those races.”

Patrick will come to the South Carolina Pee Dee with no delusions of grandeur. She understands what waits at the raceway nicknamed “the track too tough to tame.”

“I know it’s going to be hard, I know there’s going to be some frustrating moments and some moments I’m probably going to feel a little embarrassed,” she said a week ago at Richmond. “But I’m there to get my Darlington stripe and move along.”

Ah, Darlington stripes. Every car has them. The track’s configuration demands running close to the walls and contact with the barriers is inevitable for maximum speed.

Assured of a Southern 500 starting spot on the car’s owner’s points, she plans a scouting trip before the track roars to life Friday.

“I’ve got to do a few laps in anything around Darlington, I’ve heard, before I get out there in a (race) car,” Patrick told the NASCAR Wire Service in Richmond. “I’ll make sure I get there the day before . . . get a rental out there and just kind of run around.”

Patrick, 30, is a native of Wisconsin and got her start in racing with go-karts at age 10. She delved into Indy-car racing in 2002 and made the Indy 500 field in 2005. She became the first woman to lead the famed Memorial Day weekend race and finished fourth, the best finish by a female. Four years later, she finished third at Indy and began casting an eye toward stock cars.

Even with her Nationwide background, she has raced in Sprint Cup competition only in this year’s Daytona 500. She got caught in the aftermath of a Jimmie Johnson-Elliott Sadler crash on the second lap and, after her crew made repairs, finished 38th.

“I would have loved to have run up there,” she said afterward. “I would have loved to have gotten the experience when you actually were racing for positions as opposed to just feeling it out.”

That experience came on a 2½-mile speedway with restrictor plates. At Darlington, a 1.366-mile egg-shaped antique that matches 1940s design with today’s technology, the challenge will be different, and she hopes to make what she calls “baby steps.”

“Running in (Friday night’s) Nationwide race will help her a ton,” Hamlin predicted during a recent visit to Darlington.

To help prepare, Patrick and her crew spent two days testing at Nashville, a 1.33-mile oval, to become familiar with how a Sprint Cup car handles on a track that size.

“That was my first real time in a Cup car,” she told The Sporting News. “I don’t think Daytona completely counts (because) you’re really not doing much other than holding it wide open. (Nashville) was good, a lot of fun. I felt comfortable right from the get-go. You can definitely feel the acceleration of the car.”

The shorter tracks, which require more finesse, predictably have been more challenging for Patrick in her Nationwide races, and Darlington will be her toughest exam yet.

“Darlington is a challenge for the most experienced drivers,” Hamlin said. “The track is just different from the others, and it’s a test. But she will figure it out. She’s a race-car driver.”