The final heat will consist of the remaining top eight cars from the practice sessions, and the order at the end of the 30-laps will set the front four rows of the grid for the main race itself.
In the original announcement, the series had envisaged a slightly higher number of entrants at this stage of the season than the current 25 cars, and had heat 3 consisting of the top ten (rather than eight) battling over the front five rows, with appropriate knock-on adjustments to the line-ups in heats 1 and 2.
Barfield stressed that Iowa was just a one-off experiment at this point: "This is the first of a few concepts we're considering," he said. “It's going back to the heritage of short-track races."
This coming weekend's race at the Milwaukee Mile - along with the season finale at Auto Club Speedway in Fontana, California - will continue to use the traditional speed trial format for qualifying this season.
That allowed Iowa Speedway president Clements to be able to boast: "We've had a lot of firsts at Iowa Speedway with IndyCar, and the mini-races are another first," understandably hoping that the new format will boost attendance throughout the day on Friday given that the practice sessions also now form such an important part of setting the grid.