Ryan Truex's NASCAR K&N Pro Series East career started taking off last year in the fourth race of his rookie season, at South Boston (Va.) Speedway.

Truex, from the Mayetta section of Stafford Township, never had raced at SBS before. But he navigated the .357-mile quad-oval nearly to perfection, winning the pole and earning the first of seven straight top-three finishes that propelled him to the series championship.

How did Truex, now 18, manage to look as if he was familiar with every little nuance of the 57-year-old track at South Boston?

He was.

Truex had spent hours practicing in online simulations on iRacing.com. The website, which has been open to the public for less than two years and says it has more than 20,000 subscribers, uses laser-scanning technology to provide computer simulations of 40 major racetracks that Truex said are "spot-on." Simulations of various types of cars are available as well.

"I can't even explain to you how close it is," Truex said. "You go on there and learn every corner entry and where all the bumps are. Then you go out on the racetrack and every bump is just how you felt it. It's pretty helpful."

Truex logs on to iRacing.com several times each week, using a steering wheel and foot pedal that hook up to his computer. Sometimes he's studying a new track. Sometimes he's mixing it up with buddies from the K&N Pro Series. A few times, he's even gotten to race with Sprint Cup drivers such as his brother, Martin Truex Jr., and Dale Earnhardt Jr.

"I couldn't keep up (with the Sprint Cup drivers) and it wasn't very good for me," he said. "But whatever, I tried."

Martin Jr. knows most of the tracks now, having driven on NASCAR's premier circuit for four-plus years. But even he says the simulation can be good practice.

"I think it's not so much getting to know the track or learning about the track or things to actually go faster," Martin Jr. said. "You just get peace of mind when you get there and say, 'OK, I know this. I know what turn 1 and 2 looks like for the most part.' It just kind of eases your mind when you get there feeling like you've been there, and it makes you feel a little more comfortable."

For Ryan, though, it is about the basics.

"When you get there in practice, you don't have to spend 20 minutes just learning where the line is and learning where to turn into the corner and stuff like that," Ryan said.

Only a small portion of the 20,000 subscribers, obviously, are professional drivers. While Ryan frequently calls fellow K&N Pro Series drivers Matt DiBenedetto and Brett Moffitt to say, "Let's go racing," many of his online opponents never have driven a real racecar. Subscribers pay $8 per month.

"We didn't do this specifically for real-world racing drivers," said Steve Potter, iRacing's director of communications. "It's kind of a side benefit that we've created a tool that's useful."

But Potter added that the site's founders were not surprised at all when professionals such as the Truex brothers began using it.

"It's a game of inches," he said. "The small changes in the tracks, the bumps - the exact way that the radius of a corner changes - these are all things that you have to know. The survey-laser technique we use, which is accurate to within about a millimeter, it is the only way to get really accurate measurements and to get everything that's significant about the track."

The site recently became officially affiliated with NASCAR, and the Truex brothers and Earnhardt Jr. aren't the only professionals using it. Joey Logano and A.J. Allmendinger are among the numerous other Sprint Cup drivers who have accounts. New tracks are added frequently. Both tracks at Millville's New Jersey Motorsports Park are in the process of being re-created on iRacing.

"As you talk to more and more of the drivers or even the 30- to 35-year-old guys, they live on that stuff," said Cal Wells III, executive vice president of Michael Waltrip Racing, which employs both Truex brothers. "I think it's really healthy for them to do because it is relaxing. And the more sophisticated the games get electronically, with these amazing graphics and real-life situations, it can really help."

Unlike many online games, iRacing requires its subscribers to use their real names, which appear on the credit cards they use to pay. So if you're racing against Ryan Truex - or Earnhardt Jr. - you know it.

Surprisingly, this practice apparently does not cause many problems. Race fields are set based on competitors' driving records on the site. Novice drivers likely would need about a year to get their iRacing licenses to the point at which they could get into a race with a professional, Potter said. So the people Ryan Truex races against take it seriously.

"They usually have respect for the (professional) racers that come on," Ryan said. "All the people are racers who can't afford to race the real thing, but they're really good. They're not like fans who bombard you with questions."

Ryan used iRacing again to learn the track at Irwindale, Calif., before an exhibition All-Star race this year. He'll have more new tracks to learn when he debuts in the Nationwide Series this summer, so he'll be spending plenty of time on iRacing.

"He spends quite a bit of time on that computer doing that stuff," said Ryan's father, Martin Truex Sr. "I think it's good, because it makes him that much better."

Contact Jason Mazda:

609-272-7193