JOLIET, Ill. (AP) -- Facing the biggest credibility crisis in its long history, NASCAR issued a stern warning to its drivers and teams Saturday and said it won't tolerate any more attempts to alter the outcome of races.
After a scandal-filled week spent investigating teams and undoing attempts to manipulate its championship field, NASCAR came forward with a series of rules that will change the way teams have called races for years.
NASCAR Chairman Brian France told teams he expects them ''to give 100 percent'' at all times, meeting with them for nearly 20 minutes at Chicagoland Speedway on the eve of the opening race of the Chase for the Sprint Cup championship.
''I think we wanted to be very clear and we wanted to reinforce the cornerstone of NASCAR, which is giving your all,'' France said. ''We addressed team rules, a variety of other things, all designed to do what our fans expect, and that means that their driver and their team give 100 percent to finish as high up in a given race as possible. We were very clear about that. That's our expectations.''
The warning came after an unprecedented week for NASCAR, which has been rocked by allegations of race-fixing since Clint Bowyer spun his car with seven laps remaining last Saturday night at Richmond, the race that completed the 12-driver field for the Chase.
NASCAR was forced to investigate when it became clear that Bowyer spun in an attempt to stop leader Ryan Newman from winning and give teammate Martin Truex Jr. one last chance to earn a Chase berth. The investigation uncovered at least three instances of race manipulations and led to severe sanctions against Michael Waltrip Racing and the removal of unwitting participant Truex from the Chase in favor of Newman.
The central piece of evidence was radio communications, and the penalties against MWR set off a chain of events NASCAR never anticipated.
Next came allegations of a scheme to sell track position and it triggered a new investigation involving deep-pocketed Penske Racing and tiny Front Row Motorsports.
It culminated Friday with France's stunning decision to expand the Chase field to 13 drivers to accommodate Jeff Gordon, who had been bumped out of the Chase by the shenanigans of three drivers.
Gordon was pleased with the ruling, but uncomfortable with the way the week developed.
''The integrity of the sport has been put at question,'' Gordon admitted. ''I think we have one of the greatest sports that exists. To see our integrity questioned is very upsetting to me, and I think we, along with NASCAR, have to solve this. I wish it had not happened under these circumstances.''
NASCAR ultimately decided it couldn't prove Bowyer spun on purpose, but did find that MWR manipulated the race to help Truex by having Bowyer and Brian Vickers pit late in the race. The idea was that Joey Logano would bump Gordon out of a Chase spot, and Truex would get in through a wild card.
But in singling out the MWR cars for pitting to help Truex, NASCAR threw into question the long-accepted practice of deal-making between teams. That brought to light a late race conversation between Front Row team members, who were willing to have David Gilliland move aside for Logano in exchange for something it had previously asked for from Penske Racing.
When told to relay that information to Logano's spotter, the crew chief is told the request for track position is coming from the ''whole committee.''
''We've got the big dog and all of his cronies,'' the spotter said in an apparent reference to team owner Roger Penske and other team employees.
NASCAR has tightened many of the areas that allowed the manipulations to occur in a series of new rules that were outlined for the teams and will begin Sunday. Among them:
-No more deals, no offering a position in exchange for a favor or material benefit, no altering the finish, no intentionally causing a caution, no intentionally pitting to gain advantage for another competitor or intentionally wrecking another competitor. The list of things not allowed is a work in progress, NASCAR President Mike Helton said. Penalties can include suspension.
-Only one spotter per team will be allowed on the spotter stand. It means Roger Penske can no longer watch the race from his preferred perch on the roof, and NASCAR will install a camera atop every roof to monitor things.
-Digital radios are now banned on the spotter stand, meaning spotters can no longer communicate on a private channel with a team. Spotters will also be limited to two analog radios, scanners and a handheld fan device. All communications from the spotter stand to the team can be monitored by the public.
-NASCAR said it will address new restart rules Sunday. Some drivers have complained about inconsistency on how restarts have been policed all season, and fans complained winner Carl Edwards jumped early last week past leader Paul Menard. It's been overshadowed in the Chase controversy, and will apparently be addressed before Sunday's race.
Gordon had hoped the meeting would lead to positive changes for the sport.
''This has probably been coming for a couple years now and needed to change sooner,'' Gordon said. ''I like the fact that some things are going to change because all we all want to do is race our guts out every single lap. None of us want to go out there and give up a spot or race somebody different because our teammate is running for a championship. We want to go out there racing for every position, every lap, as hard as we can.''
France said he didn't speak to any drivers after the meeting, but sensed a redefining of the rules was overdue.
''This is what they want. They want to have clarity and they don't like team rules, and they don't like some of the things that have gone on in the past,'' France said. ''They're never pleased when we call them to a meeting. But I also believe that they understand what we want to get back to - it's to not worry about anything but winning races and doing your best.''
Paul Wolfe, crew chief for defending series champion Brad Keselowski, said NASCAR was clear in its meeting.
''I think it got everyone's attention,'' Wolfe said. ''I think everyone should have a pretty clear understanding ... if you go out there and run 100 percent to your ability and run a normal race, then everything will be fine.''
Seven-time champion and Hall of Famer Richard Petty believes none of the events at Richmond differed from what occurred a week earlier at Atlanta. But because of the stakes - 10 drivers vying for five Chase berths - he said the actions of a few were magnified and NASCAR had to act.
''If it had happened at Atlanta, nobody would have paid any attention to it,'' Petty said. ''But, it was a perfect storm (at Richmond). That's what makes such a big deal out of it.''
For NASCAR, the next step is getting back on track on Sunday and putting on a good, clean race.
''Circumstances happen that are unhelpful in the credibility category, there's no doubt about that,'' France said. ''You go back to what you're about, and what we're about is the best racing in the world with the best drivers giving 100 percent of their ability.''