Cup cars hitting 213 mph in draft
Hendrick Motorsports driver Dale Earnhardt Jr. said he topped 213 mph when driving with a restrictor plate that had holes of 1 1/32-inches in diameter during the session attended by 25 Cup drivers.
“You can’t tell a difference from 195 to 215 I don’t think," Earnhardt Jr. said. “I couldn’t tell a difference. We went 213 once, but it felt like 200."
Drivers returned to the mid-190s when using plates that had holes of 62/64ths of an inch in diameter – still 3/64ths bigger than what they used when the Sprint Cup cars had wings on them at Talladega last October and 1/64th-inch less than what they used at Daytona in February.
“The feedback was that the cars are stable but the closure rate was a little too much at some points, and that’s what we spent most of the afternoon working on – trying to slow that closure rate down," NASCAR Vice President of Competition Robin Pemberton said.
NASCAR Sprint Cup Series Director John Darby said the quickest lap NASCAR recorded was more than 202 mph but the suck-up speeds were higher, and he said “they’re race cars so it’s hard to say they’re going too fast but with that being said, we’re real comfortable with the mid-190-range as far as racing speeds."
In addition to the restrictor-plate changes, NASCAR also had the drivers shave off the 2-inch-high extensions on the 12 inches of the right and left ends of the wing so it was a flat 4.5-inch spoiler by the end of the day. NASCAR then decreased the width of the spoiler from 64.5 inches to 62.5 inches. The spoiler remained at 70 degrees for the entire test.
“We had some suck-up speeds that were a little faster than what we cared for," Darby said. “In conjunction with that, we had a lot of conversations with the drivers and it became apparent the car had too much drag. It was good for closing up to the guy in front of you if you were in the middle of the pack.
“But if you got shuffled to the outside, the spoiler became a parachute and it sucked them backwards just as fast as they were going forwards. That typically doesn’t make for a good race."
Whether NASCAR has found a combination it is comfortable with probably won’t be determined until the April 23-25 race weekend.
“The move to chop [the spoiler] was a good one," Earnhardt Jr. said. “We just need to go a bit shorter than that. But it’s whatever they decide. They got a lot of data today, hopefully they’ll come up with something pretty good. … [The spoiler] is still too high in my opinion. I’d say 3 inches high and 8 inches-6 inches more narrow."
NASCAR needed to conduct the test to find the right restrictor plate for the race at Talladega. That race will use a spoiler, which will replace the wing in the Sprint Cup Series within the next three weeks. The spoiler for the non-restrictor-plate tracks likely will be 4 inches high.
“A lot of the spoiler trimming we did [here] was to give the teams back the ability to stay with their competitors and have the confidence that as they raced, that they could not only stay with the draft but have enough closure speed and horsepower to successfully pass each other," Darby said. “We’ve got a very good starting spot to go home with, fine-tune a little bit and come back here and have a great Talladega race."
Earnhardt Jr. called it an “interesting" day and Darby said he doesn’t expect the height extensions on the spoilers to return in April. Darby said teams likely will be notified within 10 days on what they should bring to Talladega but there could be changes during the race weekend.
“Things on paper and things in wind tunnels look very attractive sometimes, but when you turn the lights on in the room, they have a different appearance," Darby said. “The aero formula and the engine formula we came here with were correct. And the relationship between the two probably wound up almost exact to what we started with but with a little bit of a lower scale by the end of the day.
“What we don’t have in wind tunnels and what we don’t have even with our best engineers that we work with is the input from the guys that are out there holding the steering wheels. They’re the ones that feel all the effects. If they’re not comfortable, then we’re not going to have a good race and that’s what we’re here to do."
Pemberton said that the 3 1/2-inch wicker bill that sits on the rear window and rear deck lid will be used at all tracks once the spoiler is implemented. Teams will be able to adjust the length of that wicker bill.
“It will help us with our side forces for the teams and lift-off speeds," Pemberton said. SceneDaily.com