How IndyCar's new aerodynamics kit will impact the Indianapolis 500

How IndyCar's new aero kit designed to maximize raw speed works and the problems it presents for the 2015 Indy 500.

INDIANAPOLIS — Earlier this year IndyCar’s manufacturing partners, Chevrolet and Honda, unveiled revisions to the aerodynamic bodywork of its race cars. The update was pushed out in two phases: First came an enhanced DallaraDW12 chassis for road and street course races, studded with all manner of protuberances (see graphic below) from tip to tail which were engineered to increase the downforce on the car. Then, for this year’s Indianapolis 500, came a much sleeker version for oval superspeedways that was devised to cut as fine a swath through the air as possible.

Whereas the previous body dialed up the downforce to achieve improved handling, this new speedway edition dials down drag in pursuit of raw speed. These significant changes couldn’t be more subtle, as you’ll see below.

To hear the manufacturers tell it, however, the rollout happened in reverse. “We optimized the kit first for speedway performance,” says Chris Berube, Chevy’s IndyCar program manager. “And then we started adding the road course requirements. We didn’t design [the kit] to win just one race. We designed it to win every race.”

Adds Steve Eriksen, Honda’s vice president of performance development: “Our number one goal is to win the Indy 500. And that is above all the other goals.”

With the new aero kit, the manufacturers appeared on course to set the fastest pace yet at the Brickyard. The pole speeds of the three of the season’s first five races, a mix of street and road courses, were up an average of almost two miles an hour over last year. Early practice speeds around Indianapolis Motor Speedway’s 2½-mile oval topped out at over 230 miles per hour. What’s more, the gains were achieved without much tweaking to the underbody. “It changes everything,” says Penske driver Helio Castroneves of the aero boost. “Now you’re approaching the corners just a little differently. Your speed into the corner is faster. The car has a different reaction. You’ve got to actually adapt your style.”

Helio Castroneves: I'm lucky to be O.K. after my scary IndyCar crash

The break-in process didn’t seem as if it would command much interest outside the paddock or among any fans who weren’t already of the hardcore variety until four drivers were involved in separate but equally terrifying crashes in less than a week’s time. The pile-up started in practice on May 13 when Castroneves, a three-time Indy 500 winner, spun out while rounding Turn 1, slammed into the wall and flipped over—like a paper airplane that had been launched a bit too strongly—before landing on his car’s rear bumper pods, bouncing on its side and righting itself before it came to a stop. (He walked away without a scratch and even returned to the track to turn laps in his backup car.)

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Later in that same practice, Pippa Mann spun out exiting Turn 4 and pinballed between pit lane entry path and the frontstretch. (She wasn’t seriously hurt either.)

[youtube: https://youtu.be/29XoVcDF95I]

The next day, Josef Newgarden crashed and caught air in a wreck that was eerily similar to the one that happened to Castroneves. (Newgarden is fine.)

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Three days later, in a practice session before last Sunday’s qualifying session, it was two-time pole sitter Ed Carpenter who was crashing, burning, flying and flipping over in a mangled heap. (He’s fine, too.)

[youtube: https://youtu.be/uaZ8QbTZbb0]

The incidents, which were alarming enough to consider in isolation, become even more so upon realizing that IndyCar made the manufacturers drill holes into the kit’s underwing—or the bit of the car that gives the main cabin an added measure of protection against incidental contact—to shrink the surface of the bottom of the racecar, and thereby prevent the car from lifting off. After Carpenter’s flight, IndyCar sprang into action. For the qualifying session, it required teams to cut their engine output by 40 horsepower and run in race trim (or their in-competition body configuration) to curb the possibility of further hiccups during this Sunday's Indy 500. “We’ve said all along we want to go faster,” IndyCar series honcho Mark Miles said in a hastily called news conference that afternoon, “but we want to do so safely.”

The fact that the cars involved in those wrecks were all Chevys made it appear as if Honda was being penalized for an engineering flaw that was not of its own engineering. The qualification results, which feature Chevys in all but three of the first 12 positions—including Ganassi’s Scott Dixon, a Chevy man, in the pole position—didn't exactly cut off the line that fuels trackside conspiracy theories.

Still, don’t count reigning 500 champion Ryan Hunter-Reay, a Honda driver who will start 16th, among the crackpots. “It’s a terribly tough situation to be in for IndyCar series,” he says of the aerial crashes that preceded the (relatively) slow moving qualifying session. “You have three crashes. You have three warning signs that cars are gonna flip. Now, if you go into qualifying and you have a fourth one, and it’s catastrophic? The warning signs were there, and you didn't do anything? It’s a lose-lose.”

Then on Monday, just when it seemed the worst was over, James Hinchcliffe was involved in the most vicious crash of them all, his car hitting the wall, exploding into flames, spinning out and flipping over. It was later revealed that his right front suspension failed and that a piece of it broke his car’s safety shell and pierced the driver in the legs and abdomen.

[youtube: https://youtu.be/NlbdpXb3FSg]

After a swift trackside rescue, Hinchcliffe was hospitalized and immediately operated upon; late on Wednesday, his team, Schmidt Peterson Motorsports, relayed word that he was transferred out of the ICU. On Thursday morning, the team announced that Ryan Briscoe, a veteran open-wheel driver, would replace Hinchcliffe on the grid.

While it is important to note that the Hinchcliffe crash does not appear to be like the others, which is to say an error of aerodynamics, it nonetheless raises the question of why IndyCar waited until the 500 to unveil the new bodywork—especially given its recent experience unveiling the road course body kit. The occasion for that was the season opener in St. Petersburg, Fla., in March. The story of that race was all the yellow flags that emerged for the debris that had come flying off the bodies of the cars and onto the course and into the crowd. In fact, a piece from one car pelted a woman standing near a concession stand and left her with a fractured skull.

Fans aren’t in any imminent physical danger at the Brickyard. But there is a risk of the 99thedition of the Indy 500 being slightly less exciting, competitively speaking, than the 98th—which saw loads of passes, right up to Hunter-Reay overtaking Castroneves on a daring move at the end. “In traffic,” Hunter-Reay says, “I don’t think the new car is going to draft quite as well as the old one did. With that said, I think the race is still going to be an excellent fight to the finish. But at the moment, I'm not sure.”

The fact that practice speeds following Hinchcliffe’s crash climbed back up to 229 mph on Friday is an encouraging sign. IndyCar, its manufacturing partners and its teams have had all week to get the formula right. That’s an eternity in a sport where time is short and for a group with a reputation for working quickly.

2015 Indy 500 starting grid (12:15 p.m. ET, ABC)