Dario Franchitti says it was challenging trying to describe tire marbles to DreamWorks Animation storyboard artists. Eventually, he said, “Call Firestone and get them to send you some.’’

A package soon arrived at the Southern California office, and they worked their 3D magic as displayed in “Turbo,” which opens in theaters July 17.

Franchitti was technical consultant on the adventure film about a common garden snail who dreams of winning the Indianapolis 500. Through a freak accident and a combination of circumstances, Theo is at the Indianapolis Motor Speedway.

“It was a very inspiring thing to be involved with to sit in a room with a bunch of people who are so knowledgeable and enthusiastic about something,” said Franchitti, a three-time Indianapolis 500 Mile Race winner. “I’ve watched a lot of animated films but didn’t know how they were made or what went into it. Watching these people and the detail they went into was much like sitting with engineers.”

Honing in on the details was important to Franchitti, who wanted to present the realism of the race, the Indianapolis Motor Speedway and the IZOD IndyCar Series as best as possible through animation. Hence, the bucket of tire marbles.

“(I was sitting) there with a pointer watching old races and going, ‘OK, this is why we’re doing this’ and someone asking ‘Why is the car there?’ We talked about some of the great racing films and some of the crap racing films of the past and the stuff that annoyed purists,” Franchitti said.

“It’s a snail racing in the Indianapolis 500, but much of the racing and the way the cars react they’ve tried to make that very realistic. When I saw the full-blown final cut of the first half of the film it blew my mind. Wait till you see the Indianapolis Motor Speedway. Even the finishes on the girders, the grooves on the track are the same. It’s astounding.

“I think it will be very entertaining for kids of all ages and huge for INDYCAR.  I was very excited to get asked to do it. When our sport of IndyCar has been brought into a new medium, a lot of times when you see the finished product you’re not happy with it. With the guys at DreamWorks, I knew we were in good hands.”