INDYCAR announced that qualifications for the second race of the IZOD IndyCar Series doubleheaders at Belle Isle in Detroit, Toronto and Houston will be split into two groups.

All cars will participate in one of two groups for 12 minutes each, with five minutes of guaranteed green-flag time. INDYCAR amended Rule 8.3.9.1, which had called for a 30-minute, all-car qualifying session.

In accordance with Rule 8.3.2.2 of the IZOD IndyCar Series rulebook, qualifying groups will be determined by the combined times posted by entries during the practice session a day earlier. Group 1 will consist of odd-numbered positions on the practice time sheet, while even-numbered positions will comprise Group 2.

The starting field positions will be determined by the best time ranking of the two groups combined, from fastest to slowest, with the fastest qualifier occupying the pole position.

"Splitting qualifications for the second race will give a premium to the amount of track time available to each competitor," IZOD IndyCar Series race director Beaux Barfield said. "It will improve the ability for competitors to get a clean lap and post a true lap time."

Qualifications for Race 1 will follow the regular three-round format, including the Firestone Fast Six, for road and street circuits. All six races are for full points.

Qualifying for Race 2 of the inaugural Chevrolet Indy Dual in Detroit presented by Quicken Loans is scheduled for 9:15 a.m. (ET) June 1. The 70-lap races of the Chevrolet Detroit Belle Isle Grand Prix on the 2.3-mile street course are scheduled for 3:30 p.m. (ET) June 1 and June 2.

The two races of the Honda Indy Toronto on the 1.75-mile Exhibition Place course are July 12 and July 13. Indy car racing returns to Houston for the Shell and Pennzoil Grand Prix of Houston presented by the Greater Houston Honda Dealers with twin races Oct. 5 and Oct. 6.