Motor Racing Digest

 

Posted by: Dave Thompson, follow @phillyfan17

June 17, 2012

Speeds during the extra Sprint Cup practice session on Saturday evening were down by five to six miles per hour with the new left-side tires that NASCAR and Goodyear mandated for the race at Michigan International Speedway on Sunday.

The decision by NASCAR and Goodyear late Friday evening was necessary after a number of teams tires began to blister due to the excessive heat buildup from the higher speeds produced by the newly repaved track.

Greg Biffle led the Saturday’s final with a top-speed of 195.647 mph, down from 199.093 mph in race trim on Friday. Prior to the tire change, Biffle had approached 205 mph in qualifying trim during Friday’s practice.

“The tires are really hard, you can tell,” Biffle said. ”It is giving up a lot of grip. It is kind of funny, you can hear the tires squealing when you first go out, before it builds temperature, you can feel it sliding on the racetrack. It slows the cars down, and as it builds heat it actually starts to gain some of that grip back.”
NASCAR officials made the decision to be proactive and avoid tire blowouts similar to what occurred at Indianapolis in 2008. At that race, a competition caution was called every 12 laps due to excessive tire wear which caused the tires to blowout.
The tires change was not in effect for qualifying on Saturday, when the 200 mph mark was eclipsed by 19 drivers. After qualifying, teams were left scrambling and wondering what impact the new tires would have on car setup and adjustments.

“It kind of threw us for a loop — the engine guys mostly,” Biffle said. ”They have set amount of miles we can put on the engines, and we are a little over this weekend. We are on the throttle so much around here that we are a little concerned with the engine package anyway. This is a little added blood pressure for them all day tomorrow.”

The new tire was used at Charlotte Motor Speedway in 2006 and 2007 after a repave of the track surface. The tire is a much harder compound than the one NASCAR was expecting to use at Michigan International Speedway this weekend which provides less grip, making the cars more difficult to handle.

Dale Earnhardt Jr. was on of the drivers that seemed a bit unhappy with the decision to change tires.The tire drove “like it’s six years old”, said Earnhardt.

“It’s really slick,” he added after final practice. ”Our engine guys don’t like to run over a certain number of laps. I’d like to practice more, but I can’t.”

“My car ain’t as good as I want it to be, but I can’t run more laps. This ain’t cool,” said a frustrated Earnhardt.

During the final practice session, a number of teams limited their laps to avoid engine wear. Fourteen drivers ran less than 25 laps.

The challenge for Sunday’s race is going to be which team adapts to the new tire and makes the correct adjustments on the car handling. It will also be interesting to see how these new tires hold up during a green-flag run greater than 20 laps.