How drilling holes could prevent disaster as IndyCar nears 235 mph

Ryan Briscoe gets airborne as he launches off of Alex Barron at Chicagoland Speedway in Joliet, Ill., in 2005.

INDIANAPOLIS — One of the most innovative safety measures that will be used on the Dallara DW012 chassis in the Verizon IndyCar Series is simply a hole in the floor of the race car.

INDYCAR officials discovered by cutting a hole in the floor of the car it would dramatically reduce the risk of a car going airborne during a crash. Once the bottom of the car lifts off the ground the hole will deflect air that travels over the large surface area of the bottom of the race car.

“We’re going with a hole in the floor now so that’s a new thing for 2015,” INDYCAR President of Competition Derrick Walker told “We now have part of the floor cut out to reduce the surface area of the race car. The reason we did that is when you look at open-wheel cars and racing cars in general, as ground effects has grown and grown the actual area underneath the car has gotten bigger. That sounds good as you are trying to generate downforce. But when you look at the effects if a car is not running at the right angle to the race track — if it goes nose-up — the bigger the floor, the flatter the floor, the more likelihood you have of lift.

“We at INDYCAR commissioned some studies to look at what does the current car do? What did the current car do? What can we do?

“After quite a bit of experimenting we came up with this study we have that reducing the surface area was advantageous.”

Shortly after Walker took his position as President of Competition following the 2013 Indianapolis 500 he laid out a plan that would allow the series to once again challenge for a new track record at the Indianapolis Motor by 2016 — the 100th Running of the Indianapolis 500. The introduction of Aero Kits by Honda and Chevrolet will dramatically improve the performance in 2015 as speeds are expected to make a leap toward 235 miles per hour.

Two-time Indianapolis 500 winner Arie Luyendyk holds both the single-lap track record of 237.498 mph and the four-lap average of 236.986 mph set on May 12, 1996. Luyendyk also has the fastest practice lap at 239.260 mph on May 10, 1996 — but only laps run in qualifications or the race are considered track records.

Before the current Dallara chassis can go faster, INDYCAR officials made sure it was safer to return to unbridled speed.

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“Just to be clear that didn’t come about because of the Aero Kits,” Will Phillips, INDYCAR Vice President of Technology, told “With or without the Aero Kits we would have had that floor introduced. It’s been a concern as we learn more about the car — when these cars spin air can get under it and cause lift. The first person to demonstrate that was Josef Newgarden in 2012 when he spun coming out of Turn 4 at the Indianapolis Motor Speedway. It was the first record I have of a high-speed spin of a current generation car. Since then we have been aware of it. We are constantly pushing the safety for all involved in the sport and it just took us this amount of time to have a solution that was practical and we could apply confidently as a step in the right direction.”

According to Walker, a variety of ideas were introduced before it was discovered something as simple as a hole cut out of the floor of the car would serve as an air-deflector across the flat bottom of the Dallara chassis.

“The first version of that actually had the thing on the side of the car immediately behind the front wheel — that whole section was gone and the body-line followed around the radiator like we used to have on the cars in the old days,” Walker explained. “We felt insecure about that because we like that. We call it a bumper bar or a rail across there with the angled fin. We thought this kept from interlocking wheels and that is one of the big benefits of the current car and we should retain it.

“When you look at the hole in the floor it is literally a hole in the floor of the car, but you do have the strut coming out and the rail on the outside — so interlocking-wheel prevention is still there, but the actual surface area of the car is reduced.”

After determining the hole in the floor of the car was the best approach to reduce lift, takeoff tests were conducted with very positive results.

“In the tests that we’ve had we’ve really pushed the takeoff speed up quite high,” Walker revealed. “That is something we were going to do regardless of whether the Aero Kits were coming if we could figure it out. Once we had the information and had it tested with the current car we went to the Aero Kit manufacturers and said, ‘Oh, by the way, we’re going to run with this hole in the floor.’

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“They were pretty upset initially, but they realized the safety implications and the reason for doing it. They were upset because they have done a lot of development, but we did say we were working on this — it wasn’t done in a vacuum. But they had to go back and redo some of the work. That is the advantage of the two manufacturers that we have; they understood the necessity of getting a safer aspect of the car built in. So, they went along with it and we are running these holes in the floor.”

Honda and Chevrolet are both testing a variety of Aero Kits in what is known as the homologation process. The final versions of Aero Kits will be submitted to INDYCAR for approval on Jan. 18.

According to Walker, the early data shows such an improvement in performance the series believes it may be too much; too soon.

“We knew when you change the specifications in the way we were changing the specifications there would be some gains,” Walker admitted. “Because we are trying to contain safety, speed, all kinds of aspects of competition we wondered how good it would be. We asked them and they were in development. We didn’t have real numbers — just estimates — but we didn’t know for sure. Finally, the manufacturers showed us the numbers and we saw some pretty good gains.

“At some tracks that doesn’t matter — it’s OK. At other places it’s a little too quick so we’ve taken steps to reduce the effects of the Aero Kit if necessary. I think you will see them quicker everywhere.”


Be sure to catch Bruce Martin’s Honda IndyCar Report on RACEDAY on FOX Sports Radio every Sunday from 6-8 a.m. ET.