Kyle Busch was fastest in Friday's second and final NASCAR Sprint Cup Series practice at Indianapolis Motor Speedway, while Tony Stewart and Jeff Gordon struggled to get up to top speed.

Busch posted a top lap of 184.62 miles per hour, with Kevin Harvick (184.27 mph) posting the second-fastest lap.

Kyle Larson (183.767 mph), Ryan Newman (183.673 mph) and Carl Edwards (183.554 mph) rounded out top five as far as fastest single-lap speeds went.

More from FoxSports

Stewart and Gordon, meanwhile, continued to be the most-watched drivers at the 2.5-mile track -- but struggled in the session to match the speed of Busch and other top competitors.

Stewart, making his final Sprint Cup appearance at IMS as he plans to retire at season's end, was 24th on the speed chart with a top single lap speed of 180.505 mph.

Stewart was closely followed by Jeff Gordon in 25th (180.375 mph).

Gordon is the substitute driver for Dale Earnhardt Jr. in the No. 88 Hendrick Motorsports Chevrolet this weekend, as Earnhardt continues to recover from concussion-like symptoms.

"Right now the race car and the race team are better than I am," said Gordon, the FOX Sports analyst and four-time champion who retired as a full-time driver at the end of last season. "I'm just trying to play catch-up. Hopefully we can get that done by Sunday."

The drivers with the fastest cars over an average of 10 consecutive laps were Denny Hamlin (177.938 mph), Kyle Busch (177.709 mph), Sprint Cup rookie Chase Elliott (177.016 mph), Jimmie Johnson (177.008 mph) and Kasey Kahne (176.814 mph). Stewart was at least a respectable sixth on that list (176.664 mph).

Qualifying for Sunday's race is set for 1:30 p.m. ET Saturday. There will be no more Sprint Cup practices held on Saturday.

Check out the full results from Friday's final practice below.