Aerodynamics will play an increasingly important role during this weekend’s NTT IndyCar Series race at Texas Motor Speedway.
New allowances for the fast 1.5-mile oval will give the 28 drivers on the entry list and their race engineers the potential of adding up to 10 percent more downforce than last year’s aero specification could produce, which equates to approximately 250 pounds of downforce.
At the front of the Dallara DW12’s floor, the Italian firm has produced a second optional barge board (above, in red) that adds downforce. With the increase in downforce, an increase in front ride height sensitivity also comes as part of the puzzle to solve.
On the outer flanks of the floor’s forward section, the infill Gurney flap (below, in blue) has been changed from mandatory to optional.
And at the back of the cars, the outermost portions of the diffusers have gone from an optional trimmed sidewall to channel the air leaving the bottom of the cars to optional full-length sidewalls which do a more effective job of concentrating the air and making more downforce.
The new aero options have been put through intensive computational fluid dynamics, simulation, and driver-in-the-loop testing prior to Saturday morning’s lone practice session, so most teams will have an idea on what they’ll want to try for qualifying and race setups.
But with the short 50-minute session serving as the only on-track outing for the series prior to qualifying, teams will likely be rushing to give the barge boards and Gurneys and sidewalls a try along with all of the other to-do items on their run plans.
“Texas is actually pretty interesting because of the new aero bits we get to play with,” Scott McLaughlin’s Team Penske race engineer Ben Bretzman told RACER. “What’s interesting is there’s not much running. It’s really limited and it’s gonna push everybody pretty hard on Saturday, because obviously we start running so early and you have to decide if you want to do qualifying work, race work, or both.
“The sidewall bits bring a pretty substantial chunk of downforce which also changes the ride profile on the car. So the teams have to figure out where do they want to run the cars and where do you want to take advantage of those sidewalls. Texas is different than any other oval track from the standpoint of that type of underwing configuring the right height profile of the car. We’ll see what people do with the little Gurneys; there’s a downforce gain there but will people take those off?”
Factor in the time required to get a handle on the correct pressures for Firestone’s tires along with refining camber settings, damper settings, damper builds, springs and the rest of each car’s mechanical setup, and the new aero options are part of a bigger menu of to-do items to cover from 8:10-9am Saturday morning in Texas. Qualifying for the 250-lap race starts soon after at 11:15am.
“And the new inner bargeboards are one step more you can go than just the single ones we had last year,” Bretzman noted. “The cars were really sensitive to one, so two will make it even more sensitive. With all of the steep banking that Texas has and the speeds we go and the compression we deal with in the corners, ride heights are really important to get right.
“So like with the full sidewalls at the back (above, in blue), we have to be careful to hit the optimal ride height at the front of the car with the barge boards in mind because their full effectiveness is affected by right height as well. Nailing both ends is critical, so there’s a lot for us to sort out in less than an hour of running.”