Xfinity Series aero rules for IMS put focus on blocking and restarts
There are a lot of unknowns – for drivers and fans – heading into Saturday’s NASCAR Xfinity Series race at Indianapolis Motor Speedway and perhaps that’s a good thing.
NASCAR announced earlier this year it was adapting new aerodynamic rules for the Lilly Diabetes 250, which included spoiler changes, the use of a 7/8-inch restrictor-plate and aero ducts on the front bumpers.
According to NASCAR, the aero ducts – which move air out of the front wheel wells and create a larger wake – will increase the draft envelope by approximately 25 percent, which should allow the trailing car to race closer to the leading car.
Three teams – Richard Childress Racing, Roush Fenway Racing and Kaulig Racing – tested the rules last October. For everyone else, Friday’s practice sessions were their first chance to test the unchartered waters.
“I’ve been doing this stuff for over 20 years and there are more unknowns coming into this weekend than probably I’ve ever faced coming into a race event,” said series points leader Elliott Sadler.
“I’m pretty impressed and happy with the (aero ducts). I think they have brought the competition closer together. I think there will still be a lot of the same Indy, where track position and clean-air up front are going to make a difference, but I don’t think you are going to see the leader or the top two or three cars really get away (from the field).
“I’m optimistic the race is going to be a little better than what we’ve seen here the last couple of years.”
Friday practice sessions
Sadler was fastest in Friday’s first practice while his JR Motorsports teammate, Justin Allgaier, led the way in the final session.
Kyle Busch has won the last two series races at the track. Last season, he led 62 of the 63 laps on his way to victory in the rain-shortened event. In 2015, Busch beat Ryan Blaney on last-lap pass after leading 53 of 100 laps.
Blake Koch, one of the three drivers who participated in the test last October, said the changes were greatly “magnified” during Friday’s practices in part because of the higher temperatures and 40 cars running on the track.
“Today, we were fighting a little more grip issues so we weren’t really able to team up and pass as quite as easy,” Koch said. “I still think it will be a lot better than it was – I don’t think anyone will be able to break away from the field at all.”
Two areas that are liking to see the most visible effects from the aero package during Saturday’s race will be blocking and the restarts.
“You’re going to see a lot of blocking. It’s Indy in the corners and Talladega on the straightaways,” Sadler said. “We’re racing closer and the guys behind you are going to be able to get a run on you, especially if they have help behind them.”
Allgaier said one big difference on Saturday will be when drivers attempt to push or bump-draft with each other.
“When we go to Daytona and Talladega, we all have the same rear springs (NASCAR mandates them). Here, everybody has their own rear spring package,” he said. “Some want the back of the car real low, some want it real high.
“You’re going to have to push on restarts, but the problem is going to be how hard can you push, who can you push and who is going to be able to hold on to it. I think the guys on the front row (on restarts) are going to have a big disadvantage.”
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