Celebrities start your engines!

ABC has reportedly signed a mix of 12 athletes and entertainers for Fast Cars and Superstars - Gillette Young Guns Celebrity Race, a new reality series that will provide the stars an opportunity to try their hands at stock-car racing.

According to TV Guide, the 12 celebrities participating in Fast Cars are: former What About Brian and Baywatch actress Krista Allen; former Denver Broncos quarterback John Elway; skateboarding legend Tony Hawk; seven-time rodeo champion Ty Murray; Nashville Star 5 host and Grammy nominated musician Jewel; tennis champion Serena Williams; reigning World Wrestling Entertainment champion John Cena; champion surfer Laird Hamilton; champion volleyball player and model Gabrielle Reece; former Pittsburgh Steelers head coach Bill Cowher; Star Trek and Boston Legal actor William Shatner; and former NBA star John Salley.

While they may be experts in their respective fields of athletics and entertainment, champions of the track they are not -- so the celebrities are learning the racing ropes from several top NASCAR drivers, including Kurt Busch, Carl Edwards, Jimmie Johnson, Kasey Kahne, Jamie McMurray and Ryan Newman, according to TV Guide.

Fast Cars will air as six half-hour episodes and a one-hour finale, according to NASCAR.com, which also reported the series is scheduled to run from 8PM to 8:30PM ET as a lead-in to the NBA Finals, which start Thursday, June 7 on ABC.

The celebrities' first practice sessions for Fast Cars are being held this week at Lowe's Motor Speedway in Charlotte, NC, where each is getting behind the wheel for several speed trials.  According to TV Guide, Williams looked "clearly rattled" although "her confidence had already been climbing," while Elway "made a very respectable showing" with Allen "hot on his heels."

The celebrities are practicing because the winner for Fast Cars will be determined via time trials, head-to-head heats and skills competitions that will include fastest speed, quickest driving from zero to 100 MPH, braking and pit-crew skills, NASCAR.com reported.  The final heat will feature three celebrity cars competing in time trials.

Fast Cars will be hosted by ESPN personalities Kenny Mayne and Brad Daugherty, according to NASCAR.com, which also reported that Radical Media is producing the series.

America's largest sanctioning body of motorsports has been busy in the realm of reality television as of late.  In mid-January, original American Idol winner Kelly Clarkson signed a deal with NASCAR, and her involvement includes an at-track concert, a television spot, charitable endeavors and other appearances. 

Earlier this week, it was reported that ABC News has begun production on the tentatively titled NASCAR in Primetime, a docu-reality series that will tell both the personal and professional stories of several NASCAR drivers.