>>> the sport of nascar likes to call itself the most popular spectator sport in the country. they are in the news now for reasons they are not entirely proud of. the earliest nascar drivers remember were moonshiners. now it is a multi billion dollar enterprise but there is an old expression in racing you still hear to this day. if you ain't cheating, you ain't trying. nascar is dealing with a cheating scandal and the problem with this is it was pretty much right out in the open for all to see. our report tonight from nbc's kevin tibbles at chicagoland speedway .

>> reporter: it's fast and loud and wildly popular. but many of nascar 's fiercely loyal fans are angry.

>> nascar was built, you know, mainly rednecks and integrity and all that. you know, it was just a bunch of bullcrap that happened.

>> reporter: he's referring to last week in richmond, virginia. in the final moments clinic boyer suddenly lost control.

>> i bet it's hot in there.

>> reporter: some suggest team leaders sent coded radio messages signalling him to do it. teammate brian vickers number 55 was told to make a pit stop . radio communications seem to suggest vicker is confused.

>> i don't understand. pit now?

>> reporter: vickers is congratulated when he pits.

>> oh, yeah.

>> reporter: nascar 's governing body has ruled it was done to alloa teammate to move ahead and win a spot in the chase. nascar 's playoffs.

>> stuff goes on a lot. i think people are more subtle about it.

>> reporter: nascar levelled the largest fine in the history of the sport -- $300,000 -- against the michael waltrip racing team and deducted points from each driver.

>> there was no master plan to manipulate the rice.

>> reporter: owner michael waltrip says deals have always been a part of racing. do you consider it cheating?

>> there is not a rule i saying you can't pit your car, help a teammate.

>> reporter: for nascar 's legion of fans a little bumping for position is all part of the excitement. many here today say the waltrip team went too far.

>> yes, i do think it was cheating.

>> when you're making big money , i guess you do whatever you need to do.

>> there's bending the rules and there's breaking the rules. do you think they got too close to the edge ?

>> i think they went over the line, yes.

>> reporter: citing unfair tactics by other teams, late today nascar said fan favorite jeff gordon , who didn't make the chase, would be reinstated. still as the crowds gather at the chicagoland speedway , some maintain it's all part of the game . a game in which billions of dollars are at stake. kevin tibbles, nbc news, joliet, illinois.