Pretty extensive differences in the two tests, but you still have to deal with driver bias/preferences. They are probably going to go with the setup they think will give them an advantage. Drivers being drivers.
http://www.nascar.com/en_us/news-me...an-testing-sprint-cup-series-kenny-bruce.html
Gene Stefanyshyn, vice president Innovation and Racing Development for NASCAR, said two different packages featuring various changes would be tested on the 2-mile track at MIS.
"We have a prime rules package and also will be doing a low downforce package, because some of the drivers have been very vocal," Stefanyshyn said. "They think (low downforce) is a solution ... so we're going to try one of those."
Under the low downforce package, approximately 28-30 percent of the downforce generated will be taken off the car by removal of the radiator pan (which was integrated into the current package which debuted this season) as well as the use of a 3.5-inch spoiler.
Stefanyshyn said Goodyear will bring "a sticker tire so we're going to give that a go, see what that's like."
The prime rules package will involve much greater changes and will include the use of dive planes, a 9-inch spoiler, six-percent rear differential gear ratio, three different power levels (engine horsepower) as well as a driver adjustable track bar. Dive planes are small strips on the left and right side of the front bumper areas about halfway between the splitter and hood.
The engine changes will vary from the current 850 horsepower to 800 and 750 hp. Stefanyshyn said those changes would be made during Monday's test through the use of different sized restrictor plates in order to gauge the effects. If it is determined that less horsepower works best with the aerodynamic changes being considered, how best to accomplish that for next season would still have to be decided.
"I think the aero changes that we have are the right ones," Stefanyshyn said. "We've still got to figure out the power variables ... we'll see which one provides the best racing."
The test is slated to get underway at 9 a.m. ET with six different sessions scheduled throughout the day. Teams are expected to make single-file 15-lap runs in every other session, with double-file runs making up the remaining 15-lap sessions.
Drivers scheduled to participate are:
Jamie McMurray (Chip Ganassi Racing with Felix Sabates No. 1 Chevrolet),
Kasey Kahne (
Hendrick Motorsports No. 5 Chevrolet),
Danica Patrick (
Stewart-Haas Racing No. 10 Chevrolet),
Paul Menard (
Richard Childress Racing No. 27 Chevrolet);
Brad Keselowski (
Team Penske No. 2 Ford),
Ricky Stenhouse Jr. (
Roush Fenway Racing No. 17 Ford),
Aric Almirola (
Richard Petty Motorsports No. 43 Ford),
Denny Hamlin (
Joe Gibbs Racing No. 11 Toyota) and either
Clint Bowyer (No. 15 Toyota) or
Brian Vickers (No. 55 Toyota) of
Michael Waltrip Racing.
Prior to the start of the 2014 season, NASCAR unveiled a rules package that included statically setting the race car ride heights and eliminating pre- and post-race front ride height rules.
A square leading edge was added to the splitter while adjustments were made to the rear fascia and side skirts and the spoiler height was set at 8 inches. The addition of 43-inch by 13-inch radiator pan completed the changes.
