IndyCar: Aero changes for TMS (3rd Update)

As you read on AR1 weeks ago, it was the Butt Bumpers that were getting the cars airborne and causing lift. INDYCAR has mandated that panels be installed to prevent the air from getting to the sloped surfaces inside the rear wheel guards.

UPDATE #3 A reader writes, Dear AR1.com, My hat's off to Mark Cipolloni and the AR1 team. You guys nailed the problem of why the Chevys were taking flight when they turned backwards at Indy way before anyone else, including IndyCar themselves. I recall you posted that the backside of the 'Butt Bumpers' should be closed off to prevent the lift that was occurring as air flowed through them due to the design on the Chevys. My hats off to you guys. Greg Morehead

06/02/15 As first rumored and recommended by AR1.com to solve the problem of flying Chevys, INDYCAR announced today it has implemented the use of closure panels to the rear wheel guards (AR1 calls them Butt Bumpers) of both Honda and Chevrolet superspeedway aero kits beginning this weekend at Texas Motor Speedway. The panels were developed by Honda and Chevrolet, respectively, and will also be utilized at Pocono Raceway and Auto Club Speedway during the 2015 Verizon IndyCar Series season.

"This has been a collaborative effort with both manufacturers and they have been working on these since the Indianapolis 500 qualifications," said Will Phillips, INDYCAR Vice President of Technology. "These closure panels serve as a blocker so air cannot flow through the rear wheel guards. This will ultimately raise the point at which cars would experience lift when traveling backwards."

INDYCAR also confirmed that the rear wing angle for all entries this weekend must be set between (-6) and (-10.5) degrees, which will still result in an increase in overall downforce compared to the 2014 event at TMS.

06/02/15 This post will be updated upon any official confirmation from INDYCAR, but it looks likely that there will be a new rear bodywork part or assembly coming to the rear wheel guards (Butt Bumpers) ahead of this weekend’s Firestone 600 Verizon IndyCar Series race at the Texas Motor Speedway.

A Twitter post from USA Today Sports' Brant James said to expect a new aero part, described as a new "contraption," coming to the cars this weekend.

INDYCAR president of competition and operations Derrick Walker said during the qualifying change press conference at the Indianapolis Motor Speedway that INDYCAR, in partnership with Chevrolet and Honda, would seek to make changes before the race at Texas.

"Well, we've already started and it will go as long as it takes to get the answers we need," Walker said on May 17. “Both our manufacturers are working very closely with us. That's one of the reassuring things of this whole exercise is how they’ve rallied around and put all their resources behind looking at how to understand it more, so I would see that motorsportstalk.nbcsports.com

05/31/15 I'm hearing here at Detroit that INDYCAR is going to mandate aerodynamic changes for the cars next weekend at Texas Motor Speedway. Will this be the change in the 'Butt Bumpers' as AR1 President Mark Cipolloni has urged?

My guess is we'll hear something in the next day or two.

Lucille Dust reporting from Belle Isle