Aero changes chip away at Indy flyover risks

Aero changes chip away at Indy flyover risks


Aero changes chip away at Indy flyover risks


Three times this month drivers bounced off the Turn 2 wall at IMS and appeared headed for the dreaded Tommy Tipover at big speeds. But Felix Rosenqvist, Pato O’Ward and James Hinchcliffe (pictured above) seemed to defy gravity or physics — or both — and instead of flipping they all came back down on the track right-side up.

Was it luck or the changes IndyCar and Dallara have made to the car since a trio of flyers in 2015?

“Nobody went over, so that’s good,” responded Bill Pappas, IndyCar’s vice president of competition and race engineering who along with Tino Belli rides herd on the rules, mechanics and aerodynamics of IndyCar. “But we’ve already started speaking with Dallara about what’s the next step when the car gets up on its side like a Frisbee, so we’re throwing around some ideas.

“Is there a way to ensure it always falls back down? We’re seeing if there’s something we can do and we’re not resting on it.”

It was 2015 when Helio Castroneves (pictured above), Josef Newgarden and Ed Carpenter took flight but all miraculously escaped injury.

“In the old days cars didn’t have big underwings and flat surfaces so they didn’t fly, but they would somersault,” said longtime team manager/owner Derrick Walker who was IndyCar’s competition chief from 2012-’15. “In 2015 the cars that were flying were all Chevys and data showed Honda could have done it but never did. The manufacturers were sending simulations to their teams every night and the next day we’d meet to see what they discovered.

“We decided to add more downforce and not add more boost for qualifying because we couldn’t afford any more flying cars. We got through the weekend but both manufacturers were mad. Chevy thought they had an advantage and the Honda guys thought they were being penalized but I’ll always compliment them for trying to find a cure.”

IndyCar allowed Chevy and Honda to make their own body kits starting in 2015, but required a new spec floor with holes in the underbody so the car wouldn’t have as much surface area when it got to the wrong angle in a crash. Dome skids and beam wing flaps were introduced in 2016.

Since then, other than Sebastian Bourdais’ massive hit and flip in 2017 and Scott Dixon being launched after running over a spinning car a week later, Indy cars have either remained upright during an accident at the Speedway or tried to tip over before returning to earth.

Getting rid of those manufacturer aero kits and scaling back downforce has certainly helped the situation and Pappas credits a couple of things in addition to the holes in the Dallara.

2019-spec speedway cars have tested the limits but stayed right-side up to date. Image by Phillip Abbott/LAT

“We built this kit last year and added lateral bulges on the outer edge of the underwing to keep the car planted on the ground and we did what we could to simulate the dome skid that was introduced in 2016, and it seems to be a big deterrent for flying cars,” said the former race-winning engineer for Juan Montoya, Gil de Ferran and Justin Wilson.

“We also put flaps on the back of the underwing that pop up when the car spins and that helps keep the back end of the car down.”

Pappas says moving the radiators forward and creating side protection for the driver has also helped driver safety but still wants to get a handle on controlling the air that gets trapped under the car when it’s sideways coming off the wall.

“We need to find a way to release that air that is packing up under the car because that’s what causes it to take off. Three of the four drivers pinched the corner, spun around into the wall at an odd angle and bounced off the SAFER barrier, so we need some sort of venting to try and keep the car planted.”

Walker acknowledged that it’s a challenge for IndyCar.

“These cars weren’t designed to go backwards or sideways at 150-200 mph but IndyCar and Dallara have done good continuing to minimize the lift issue with the use of computer simulations,” he said. “That’s enabled better control of what happens when a car gets out of shape at 200 mph.”