INDIANAPOLIS — NASCAR might need to go back to the drawing board in its quest to create more competitive stock car racing at Indianapolis Motor Speedway.

NASCAR officials debuted a “high-drag” aero package in Sunday’s Brickyard 400, featuring a nine-inch spoiler and other measures intended to slow the cars down and punch a big hole in the air, which officials hoped would create drafting and pack racing.

But the racing didn’t look much different from previous NASCAR races at Indy. With the exception of some wild restarts, the racing was largely single file.

Kyle Busch didn’t have many complaints — he won the race. Other drivers didn’t really see much that they liked. Kevin Harvick called it a “huge science project that probably didn’t really change that much.”

“I think everybody put in a lot of effort to try to really make everything a lot better, spent a lot of money, but I don’t know that we accomplished everything that we were looking to accomplish,” Harvick said.

VIDEO: Drivers analyze aero package at Indy

Brad Keselowski was disappointed the changes weren’t more effective.

“I think we were all expecting there to be more drafting than there was,” Keselowski said. “I don’t think the draft was much different than last year and the penalty for being behind someone in the corner was more significant.”

Kasey Kahne saw a “little gain” in terms of being able to close on cars on straightaways.

“You could suck up a little better if there were cars around,” Kahne told USA TODAY Sports. “If there were just two cars, there was no gain there. The problem is you can’t go through the corner behind a car. It makes the inside so preferred, the big spoiler and all that blocking air, you can’t even think about being on someone’s right side — or even a foot to their right side.”

Added Martin Truex Jr.: “I thought it was harder to pass than it’s ever been. Similar to last year with the really big spoiler, there was a little bit more of a suck-up on the straightaway. But I didn’t feel like it was enough. You could just barely stay close enough to the guy through the corner to get to him by the time you got to the next one. There wasn’t enough there. We didn’t see much drafting, we didn’t see much of that pack racing style.”

And there were at least two unintended side effects of the larger rear spoiler:

–Hot air seemed to build up and linger underneath the cars, more than it usually does — not exactly what drivers were looking for on a hot and humid day in Indianapolis.

“(The) cars are extremely hot inside,” Harvick said. “That was probably the biggest surprise that crept up on everybody.”

–And because of the larger spoilers on the cars lined up in front of him on restarts, Truex said he had trouble seeing where the restart zone was, costing him split seconds of reaction time — and that might have kept him from helping Harvick with a push on a late restart.

“It was really hard to see through these things with that big spoiler on there,” Truex said. “I couldn’t see the restart line coming, and my normal spotter was spotting the backstretch, so the spotter that was on the front, we don’t have really good communication yet, and I forgot to ask for it.”

Truex apologized to Harvick, saying, “it cost him the race for sure.”

All said, Harvick wondered whether the changes were worth the time and money they cost NASCAR teams.

“I know my team did a lot of extra work to come to this race after we had already come here and tested and already spent that money to come here and test for a few days,” Harvick said. “And then to come back and have to race something different was a huge undertaking for the teams for a huge science project that probably didn’t change that much. But everybody tried real hard, and in the end, I think (our) goal is more drafting and more pack racing so we’ll see if we can get to that.”

Would drivers bring this package back next year?

“Not if I was in charge, but I’m not in charge,” Denny Hamlin said.

NASCAR is expected to use a similar package when teams run at Michigan International Speedway on Aug. 16.

Contributing: Jeff Gluck, Mike Hembree