Restrictor plates part of Xfinity's Indy aero package

NASCAR has announced the Xfinity Series package for the July 22 race at Indianapolis Motor Speedway, and it includes restrictor plates.

The race-specific requirements for the 100-lap include a taller rear spoiler and splitter package, aero ducts on the lower front bumper area and a 7/8th-inch restrictor plate that's currently used at Daytona and Talladega superspeedways. The static ride height of the cars will stay at four inches as is used in the current 2017 rules package.

Xfinity Series teams from Richard Childress Racing, Roush Fenway Racing and Kaulig Racing took part in a test in October to help determine the package.

"We race at 29 tracks (across all three national series) and they're all very special," NASCAR senior vice president, innovation and racing development Gene Stefanyshyn told NASCAR.com. "Indianapolis has a long history; it's a wonderful track. Our objective is to give our fans the best possible show we can. We are very proud of being able to participate at Indy; we want to put our best foot forward. We believe we have come up with a package that gives us the best opportunity to do that."

"We saw the cars were closer together, but we weren't able to create some passing until we introduced the aero ducts," he said. "That's the main purpose of the ducts, to give the trailing car more of an advantage ... we always hear about clean air and how the leader has clean air. Our objective here is to try to give the trail car more benefit."

Given the limited ability to test, it's still an unknown whether the package – which is specific to IMS and not expected to be used again in either the Xfinity or Monster Energy NASCAR Cup Series – will be beneficial.

"Our belief is that we will create a situation where they can pass on the straightaways," Stefanyshyn said. "That's been done analytically, it's been done with three cars. The question is when we turn 40 cars loose on the track can that still manifest itself and that's still what we're hoping will happen."