The Verizon IndyCar Series’ plan to race at Texas Motor Speedway with low downforce has been slightly modified to suit the high ambient temperatures expected throughout the two-day event.
Teams and drivers will still run with less overall downforce than was available in qualifying for the Indy 500 (pictured), but with temperatures above 90 degrees F on tap, the series has adjusted the maximum rear wing angle from negative six degrees to negative three degrees to compensate for the thinner air.
With the same speedway rear wing element in place as used at Indy, the extra three degrees of wing angle should add approximately 100 pounds of downforce to the rear of the Chevy- and Honda-powered Dallara DW12s.
The original setting of negative six degrees was defined after IndyCar conducted tests at Texas with the new-for-2018 universal aero kit, but those findings came in ambient conditions that were 20-25F cooler than is anticipated for Saturday Night’s DXC Technology 600 race. The speedway front wing is also part of the package, and like Indy, no limits on the angle of attack have been set. Gurney flaps are allowed for tuning the front wings only.
Teams are also required to remove both sidewalls from the diffuser exits, and a pair of inverted Gurney flaps have been implemented at the rear of the floor to further reduce downforce generated beneath the cars. Teams had the option of keeping the sidewalls on for the Indy 500, which was adopted by all 33 cars. It ensured the floor contributed somewhere between 225-250 additional pounds of downforce to the overall package. Minus the sidewalls, and with the inverted flaps affixed, the floor has become IndyCar’s focal point for slashing downforce at Texas.
Adding to the complex puzzle for IndyCar race engineers to solve, Firestone has a new tire compound for Texas, and with a single 90-minute practice session prior to qualifying, Friday’s first outing will be jam-packed with learning about the aero, mechanical, and tire needs for the 248-lap race.
The light downforce approach by IndyCar comes in an effort to reduce pack racing on the fast and treacherous 1.5-mile banked oval. With last year’s race serving as one where multiple crashes took 10 of the 22 starters out well before the finish, drivers are not expected to have the luxury of running close together for extended periods with the new aero kit in place.