AutoMatters+: Four Tires in Fontana & a Review of “Insurgent”

Kyle Larson’s Sprint Cup stock car #42
Fresh tires are a key to the race

Auto Club 400 NASCAR Race Weekend

The grandstands were packed with a sellout crowd for this year’s “Auto Club 400” Sprint Cup NASCAR race at Fontana’s Auto Club Speedway. A late race caution for debris on the track turned the race into a real nail-biter. Cautions often breed more cautions, and this was no exception, adding nine laps to the scheduled 400-mile race and changing the expected outcome.

Carl Edwards & Sam Hornish Jr. saluting their fans

Most of the drivers came in for fresh tires, but should it be two or four? Two would be quicker, but would it be the best choice? Late race leaders Kurt Busch and the hard-charging Kevin Harvick each took two. In response, as we learned in the post-race interviews, Paul Wolfe — Brad Keselowski’s Team Penske crew chief — told his driver over the radio: “If we’re going to win this thing, I think we’re going to need four.” He told us that “It’s one thing to have the four tires and have the grip, but Brad did a great job of executing the passes, making the holes and taking the opportunity to make use of the tires.” Keselowski’s upset, come-from-behind, well-earned win was nevertheless a shocker.

A sellout crowd at Auto Club Speedway

Harvick, the Sprint Cup Series points leader, has finished in first or second place in the last eight consecutive races. This places him only three races behind the record of Richard Petty, who scored 11 in 1975.

The day before, on Saturday, Harvick won the “ 300” NASCAR Xfinity Series race. He won by such a large margin that he made it look easy.

Plenty of racing room through Turn 4

Exciting races at Auto Club Speedway might come as a surprise to some. This track is extremely wide, giving drivers plenty of room to race cleanly and stay out of each other’s way, yet it is also very bumpy — a consequence of having a very old track surface.

As in all Sprint Cup races, at any given pit stop, the crew might need to change tires, add fuel and adjust the car for variables that include changing temperatures and damage.

Jeff Gordon narrowly misses the spinning David Ragan
Jeff Gordon narrowly misses the spinning David Ragan

Adjustments to the various aerodynamic elements significantly affect the handling of a NASCAR stock car. One such aero element is the front splitter — a thin, horizontal, rigid strip that sticks out, shelf-like, from the bottom of the front of the car, spanning its entire width. When its height is adjusted optimally, at high vehicle speeds the air passing over and under the front splitter produces high aerodynamic down-force at the front of the car. This is due to a combination of a high air-velocity, low-pressure area under the car; and a low-air velocity, high-pressure area above the car. This down-force will increase the grip of the front tires, so that the car turns instead of sliding sideways (a condition known as “push” or “understeer”). If the front splitter is too low, that will reduce the speed of the air passing under the car, increase the pressure under the car, and reduce down-force.

A late race pit stop

On a bumpy track, the front splitter on a racecar with a suspension that is too stiff suspension will no doubt vary its height above the ground. A suspension that is too soft will result in lean, once again affecting the relative position of the front splitter to the ground. Both will reduce down-force.

A late race restart through Turn 1

In addition to the racing, fans were entertained in the O’Reilly Auto Parts Fan Zone. There was plenty to see, do, collect and eat — by race fans of all ages.

Review of “Insurgent”

Set in the future, “Insurgent” is the first sequel to last year’s “Divergent.” A devastating war had raged, and in an attempt to restore order and peace, society had been divided into factions. Many also were Factionless, and then there were the Divergents — considered unwelcome deviants who were perceived as an existential threat to society.

“Insurgent” is a story about how a ruthless faction leader tries once and for all to eliminate the Divergents. She will stop at nothing to do that. There is also a significant plot twist, which makes me really want to see the next sequel.

Whereas “Divergent” was fresh, fascinating and original, “Insurgent” is more of a “been there, done that” kind of experience, which tends to make it forgettable pretty quickly. Hopefully, the next sequel will be more out of the box — or perhaps I should say out of the wall.

Brad Keselowski celebrates with donuts

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Copyright © 2015 by Jan Wagner – AutoMatters+ #377