To help teams prepare for the change, Sprint Cup officials will hold an extended practice session, likely four hours total, on Wednesday, July 8, at the 1.5-mile track located in Sparta, Kentucky. The Quaker State 400 Presented by Advance Auto Parts is scheduled for Saturday night, July 11 (7:30 p.m. ET, NBCSN, PRN, SiriusXM).
"I know we’ve said it many times, and certainly want to reinforce it here, that we’re committed to putting on the best racing on the track, and I’m certainly pleased that it’s been evident from really every conversation we’ve had with our industry that they feel the same way,” O’Donnell said during a national teleconference.
"So following what’s been really well‑documented and unprecedented communications and collaboration with our OEM partners, the race teams, drivers and Goodyear, we’ve made the decision to move forward with the package."
According to O’Donnell, the spoiler height will be reduced from 6 inches to 3½ inches and the splitter extension panel (radiator pan) decreased from 38 inches to 25 inches. Additionally, the splitter will have 1¾ inches less overhang than the current splitter.
Initially, a version of the rules package that included lowering the spoiler height as well as changes to the splitter and splitter extension panel was scheduled to debut next year. But with this year’s lower downforce/less horsepower platform resulting in a continued increase in corner speeds and a fall-off in the amount of green-flag passes, officials stepped up their efforts to get the changes in place ahead of schedule.
MORE: Ray Evernham and Jimmy Makar discuss how the Kentucky package will impact cars
The 2015 and proposed ’16 changes specifically target competition on the speedways, those tracks that are more than a mile and up to two miles in length. They have little or no impact on short tracks and road courses while the series’ two superspeedways, Daytona International Speedway and Talladega Superspeedway, have a separate rules package in place.
For now, the changes are only in place for Kentucky, however O’Donnell said, "any options are on the table."
However, it is too soon, he said, to speculate on possibly incorporating the package in future events, specifically this year’s Chase for the NASCAR Sprint Cup.
"I think it’s still … premature on that one in terms of we want to get through Kentucky, really analyze what we saw at that race, have some conversations with the industry and go from there," he said.
NASCAR made several modifications prior to the start of the ’15 season aimed at enhancing on-track competition. Among the changes was a reduction in horsepower through the use of tapered spacers, lower rear differential gears, shorter spoilers, a smaller radiator pan (underneath the cars) and an optional driver adjustable track bar.
RELATED: 2015 competition changes
Through the first 15 races of this season, the number of on-track passes under green-flag conditions is still second-most in the loop data era, which started in 2005, but it has fallen off from a high last year (64,611 vs. 60,922). Lead changes aren’t limited to those battles on pit road and the hurried rush of a restart, but the majority of them now occur on those occasions.
The reduction in horsepower has allowed drivers to stay on-throttle much more through the turns, and the aero changes haven’t noticeably impacted the advantage the leader has enjoyed while in clean air.
Taking downforce away could result in more off-throttle time for drivers in the turns because the cars won’t be as stable, and potentially lessen the aero advantage enjoyed by the leader.
Most drivers queried about the possible change last weekend at Michigan International Speedway said they approved of the timing if NASCAR chose to roll out the changes at Kentucky.
Brad Keselowski, the 2012 Sprint Cup champion, said it’s a constant battle as the sanctioning body strives to provide a quality product while the teams continue to innovate.
"In that tug of war, anytime NASCAR changes something to try to make the racing better, whether that is aerodynamically or engines or some other change, we seem to have the resources … to gain that back, whatever they might take away with a rules change," Keselowski said Sunday at MIS.
RELATED: Drivers discuss rules changes
Teams have "significantly outpaced" the sanctioning body when rules changes have been implemented, particularly in the area of aerodynamics.
"We have seen the cars gain 200-300 percent in downforce the last 10 years," he said. "At some point, NASCAR is trying to get out in front of that and that is their job, to keep the racing as good as it can be. In that sense, I completely agree that you have to continuously change the rules to keep up with the teams and the iterations that we come up with to make our cars perform that aren’t necessarily in the best interest of the sport. To me, it is a good sign to see them trying to do just that."
Richard "Slugger" Labbe, named on Monday to the crew chief role for the Richard Childress Racing No. 3 team and driver Austin Dillon, told SiriusXM NASCAR that the aero changes will be impacted greatly by the tires being supplied by Goodyear.
"It all comes down to what tires we put on the cars," he said. "How Goodyear reacts to it, to me, is going to be very, very important. … A lot of it depends on how much grip is in the tire if you go with the max downforce package."
MORE: Labbe’s goal to return No. 3 to Victory Lane
Goodyear had been prepared to test a tire to be used with the lower-downforce package at Kentucky in mid-April with the idea that the aero rules would be in place for this year’s NASCAR Sprint All-Star Race at Charlotte Motor Speedway, a non-points event. However, NASCAR eventually decided not to use the package at that time.
Now, with the Kentucky race only a month away, Goodyear officials say there isn’t enough of a window to produce the 2,200 tires needed and no data exists to determine the proper build to match with the new package.
"Back at Charlotte, we had enough lead time," Stu Grant, general manager, global race tires for the company, told NASCAR.com Sunday. "When you test in March, you can make a tire for May. But the process is so labor-intensive … it’s months in the making to do that. You can’t turn the Queen Mary on a dime."
The production run for the Kentucky tires had already been completed when the subject of the aero package changes resurfaced.
"Certainly (the Kentucky tire) is not going to have the grip that they want," Grant said.
RELATED: Grip — what every driver wants and how to get it
O’Donnell said the plan to incorporate the changes into the All-Star Race was scrapped due to time constraints. With the Sprint Cup Series off this weekend, and stops at Sonoma and Daytona up next, teams have three weeks before the Kentucky race.
"I think the key there is having everything fully vetted, the (simulation) work done, the communication with the industry and (having) everybody fully aligned," he said. "And candidly, at the All-Star Race, it was an aggressive plan, and we just weren’t there at that time, but we are there now.
"We feel like this is the best package we can put forth as an industry for the race in Kentucky and feel confident in it."
