Dallara will carry out minor modifications to the 33 DW12 IndyCar chassis set to compete in Sunday's Indianapolis 500, cutting three slots in underwing supports of the new cars to lessen lateral and maintain vertical stiffness.

Testing by Dallara earlier this week found that the stiffness of the underwing supports might have been a contributing factor to cars slightly lifting off the racetrack in three instances during qualifying weekend at Indianapolis, when they impacted the SAFER Barrier with the car's centerline parallel to the wall. The modifications are being carried out at the Italian manufacturer's new U.S. base in Speedway, Ind.

"Dallara's response has been immediate to try and make sure all improvements possible could be implemented in time for the race – all credit to them," said Will Phillips, IndyCar's vp of technology. "Feedback from observers, safety officials and drivers enabled Dallara to have the data very quickly, and their solution and response is a great example of how safety comes first."

The simple modification will be complete for Miller Lite Carb Day on Friday, on all 33 cars in the starting lineup.

Through the nine days of practice and qualifications, five crashes were recorded. All competitors – Josef Newgarden, Bryan Clauson, Oriol Servia, Ed Carpenter and Charlie Kimball – were checked at the infield medical center and cleared to drive.