If the 107th Indianapolis 500 is run in similar ambient conditions to last year’s race, NTT IndyCar Series teams will have the ability to apply approximately 250 additional pounds of downforce to their cars if all the new and existing aerodynamic options are installed for the May 28 contest. All of the items will make their debut at this week’s Thursday-Friday Indy Open Test.
The biggest year-to-year change is found at the rear of the Dallara DW12s, which wear the sleek UAK18 bodywork that was introduced in 2018. Two downforce-adding items have been produced by Dallara, starting with new rear wing pillars which enable a valuable increase in wing angle range. The idea was originally suggested to the series by Arrow McLaren driver Alexander Rossi.
Previously limited to a maximum of two degrees of positive inclination, the new rear wing pillars make it possible to crank up to nine degrees of downforce-increasing angle into the rear wing, but for this year’s event, the series is limiting a maximum of five degrees.
Attached to the rear attenuator with a sliding mounting mechanism, the pillars (in blue) can be quickly adjusted during a pit stop with a socket on a speed-handle to increase or decrease the rear wing angle to suit the driver’s needs.
The move to the new pillars and a higher ceiling for rear wing downforce will be useful in Indy 500 practice sessions when drivers run in packs and work with their teams to refine the car’s aerodynamic balance in turbulent air, and on race day. No changes have been made to limit going in the opposite direction on wing angle for qualifying, where teams run at negative numbers — nose up — to shed downforce for the four-lap blasts.
According to A.J. Foyt Racing technical director Michael Cannon, who earned the last two Indy 500 pole positions at Chip Ganassi Racing with Scott Dixon, the new pillars will have a surprisingly large impact on the race.
“In the past, you were allowed a maximum of plus-two degrees and after that, you start putting Gurneys on to make more downforce because you were limited on wing angle and the Gurneys were a workaround to get more, but it didn’t help the cars behind,” Cannon told RACER. “So with what they’ve done here in giving us up to plus-five, we have more steps of downforce we can go, and each degree is a nice little increment.”
By giving teams three extra degrees of rear downforce to use, the reliance on wide Gurney flaps should subside, and as a result, turbulence should be reduced, which could inspire more passing attempts.
“Ever since we’ve had the aeroscreen, if you’re the leader, life’s not so bad,” Cannon said. “If you’re second, you’re starting to get some turbulent grief. And when you’re the fifth car in line, you’re losing over 20 percent of your downforce. So that’s why you’ve seen people [when the maximum was plus-two degrees] rock up during the race with full-span Gurneys on the rear wing and they’re competitive because they’re living back in misery-ville. They’re in the big vacuum.
“The guys that have the big rear wing Gurneys on have that much more grip, and when the guy in front of them that’s on a little bit less downforce has to lift, the big Gurney guy just leaves his foot in it and gets past him.
“It’s not the race-winning downforce with the big Gurney, but it’s good survival downforce. What they’ve come up with is the ability to take it to a higher angle and have more downforce while also keeping the efficiency of the car decent and reduce some of the turbulence. And it’s the turbulence coming off the cars that’s bouncing you around and making the car nervous because if you’re running behind somebody that’s got a full-span Gurney, there’s a lot of tumbling air behind there and it’s pretty messy to sit behind. So, giving us some extra range to make more downforce with the wing should help everyone to go away from those full-span Gurneys.”
The other new allowance for the Speedway is the optional use of one-inch Gurney flaps at the trailing edge of the diffusers (in blue), which is a carryover from IndyCar’s road and street course rules. Use of these Gurneys are a nice way to add downforce through the car’s underwing, and since these tall flaps aren’t sitting up high in the airstream like a Gurney affixed to a rear wing, they do not create an excessive amount of turbulence.
With the new five-degree rear wing angle maximum and the optional diffuser-exit Gurneys, teams have newfound abilities to dial up downforce in race-day configuration, but since drivers need their cars to be balanced front-to-rear in order to have confidence in its handling, teams will need to add matching levels of downforce to the front of the cars.
Race engineers will use the familiar front wing adjusters to apply more downforce, and have a new option to install a second barge board (in red) which debuted at Texas Motor Speedway and mounts to the inside of the other optional barge board, which was used last year. Each barge board increases downforce, but also increases front ride height sensitivity, so it will be interesting to see if teams opt to run with the single barge board on both sides of the car, or try double barge boards and trade the downforce gains for imperfect handling.
“If you’ve got a bunch of rear wing angle on the car, you’ve got to find a way to get balanced at the front,” Cannon noted. “So it’s great that we can have more rear wing, but you might have to do some things to balance it at the front that aren’t great, so I don’t think everybody’s going to pile on everything they can get, but it all depends on the weather because you never know what you’re going to get. But it’s nice to have a range of downforce options, even if we don’t use all of it.”
Finally, teams have the optional Gurney to install on the wing-shape infill at the outer portions of the front floor section, and in a mandatory addition for every team, stability Gurneys (in green) make their debut along the top outer edges of the sidepods and rear tire ramps.
The series will also introduce a new and taller cockpit head surround at the Open Test. The revised design was done to prevent a driver’s helmet from scaling over the back of the longstanding design in a rearward impact.
Production is ongoing, with a plan to have one for every entry as the month of May begins, so for the test, IndyCar will distribute 18 of the new safety devices (in blue) — ensuring every team has at least one — with the hope for multi-car teams to ensure each driver samples it at speed before they become mandatory for the start of official practice in just under a month.