Dr. Diandra: Turning at Talladega: 100 mph on ice


The secret — and the challenge — of winning NASCAR races is in the turns. While we normally focus on drafting and pack racing when NASCAR visits Talladega Superspeedway, Talladega was built for turning fast.

Even if you covered the turns in ice, a car could still take them at about 100 miles per hour.

To understand how that’s possible, we have to first understand how cars turn under normal circumstances.

How race cars turn

Talladega is just plain huge. The infield is 247 acres. That’s big enough to fit the Disneyland theme park (160 acres, which includes only the theme park and not the whole resort) and still have enough room left over to almost get the Mall of America in there too — which, come to think of it, is not a bad way to describe the tamer parts of the Talladega infield.

Large tracks like Talladega give drivers more time to build up speed down long straightaways. Wide, sweeping turns don’t force cars to slow down as much as tracks like Bristol or Martinsville.

At Bristol, about 60% of each lap is turning. At Talladega, it’s more like 10-15%. But even at only 10% of the race, drivers can’t win Talladega unless they can master its corners. The turns are where speed is gained or lost. How a car exits a corner determines its ultimate straightaway speed, and how the car enters a turn plays a large part in how it exits.

The force that makes a car turn is called the centripetal force. Even if you’re not familiar with the word, you already know all about centripetal force. You experience it every time you use a cloverleaf highway interchange or ride a merry-go-round or a loop-the-loop roller coaster.

The word ‘centripetal’ means center-seeking. Since cars turn left and right, you may wonder how the turning force always points toward the center of the turn.

Let’s do a thought experiment. Imagine tying a ball to a string. Now whirl it over your head in a horizontal circle.

The string forces the ball to travel in a circle. At every point on the path, the force on the ball points toward the center of the circle, as I’ve shown below.

A graphic showing a ball whirling around in a horizontal circle on a string, and the forces keeping it in a circle
The ball moves in a circle because the string forces it to do so via centripetal force. Centripetal comes from Greek and means ‘center-seeking’. The centripetal force always points toward the center of a turn.

The exact same physics apply to a race car — except the numbers are bigger.

The minimum weight of a Cup Series car (with driver) is about 3,675 pounds. Let’s turn the car in a circle with a radius of 1,100 feet, which is about the turn radius at Talladega. A driver taking the turn at 190 miles per hour requires a little more than 8,000 pounds of force.

That’s four tons.

If the force is any less than that, the car breaks traction and hits the wall. Then we’re talking about some very different physics.

Of course, race cars don’t have strings. Those four modest-sized patches of tire rubber in contact with the track must create those four tons of turning force.

A graphic showing how a race car turns and the directions of the forces making it turn.

In the video below (from the FS1 broadcast of the Martinsville Cup race earlier this month), I’ve shown how the centripetal force points toward the red-and-white curbing throughout the turn. You can also see how exiting the turn prepares the driver to take the best line down the straightaway.

But tracks like Talladega give the tires a little more help turning the car.

Taking it to the bank(ing)

Martinsville is a half-mile track with only 12 degrees of banking. Pole speeds tend to be in the mid-90 mph range. Compare that with Bristol, a similarly small track, but with pole speeds around 130 miles per hour. Banking makes all the difference.

In addition to being the longest track, Talladega has the highest banking of any track NASCAR runs this year: 33 degrees. For reference, most modern staircases have angles between 30 and 35 degrees.

Below, I’ve drawn the banking of a couple NASCAR tracks to scale.

Comparing the baking at Martinsville, Auto Club of California Speedway and Talladega

That banking is magic. To understand why, let’s look first at how a car turns on a flat track.

In the diagram below, the car is turning left and you’re looking at it from behind. The centripetal (a.k.a. turning) force points left at the moment we snapped these pictures.

The left track is flat. I’ve indicated the force the track exerts on the car with red arrows and labelled it ‘track force’. Gravity (which I didn’t show so as not to clutter the diagram) points straight down and exactly offsets the track force. That’s where friction originates.

But gravity and the track contribute nothing in the left or right directions that might help (or hinder) the car turning.

A graphic describing the forces acting on a car on a flat and on a banked track.

Now compare that with the same car turning on a banked track, which I show on the right side of the above picture.

Gravity still acts down. (Gravity always acts straight down.) The track force is still perpendicular to the track. But when the track is banked, some of the track force points in the direction of the centripetal (turning) force.

The banking actually helps the car turn.

Of course, there is a trade-off. A banked track provides slightly less frictional force. But the net effect is that a banked track allows a car to turn faster because the banking contributes turning force. The force from the banking adds to the force from the tires. The higher the banking, the more turning force help the track provides.

Talladega on ice

In fact, a banked track can provide so much help turning that it can compensate for a loss of friction.

Imagine a sudden, concentrated storm that covers Talladega’s Turn 4 with a sheet of solid ice. The tires don’t touch the track at all in that turn. There is no friction.

Because of the 33-degree banking, a car could still travel through turn four at Talladega at a maximum speed of just about 103 mph.

That’s not to say the car would be well behaved through the turn: It would be sliding instead of rolling and you wouldn’t be able steer – but you would make the corner.

At Martinsville, with only 12 degrees of banking and about a 200-foot turn radius, the maximum speed at zero friction would be only about 37 mph.

If a car travels too slowly around a high-banked track, gravity will pull the car down the banking. We will likely see that this week at Talladega, and next week at Dover, as well. Dover’s reputation as a ‘self-cleaning track’ originates from physics.

On a banked track, you have to move fast to beat your competitors – and to beat gravity, too.


Short-track ace Sam Ard shares Xfinity record with Noah Gragson


Former two-time Xfinity Series champion Sam Ard’s name returned to the forefront in the past week as Noah Gragson tied Ard’s series record for consecutive victories at four.

Although Ard has been nominated for the NASCAR Hall of Fame, his exploits generally aren’t well-known among many who follow the modern sport of stock car racing. He was on the Hall voting list for the 2023 class but was not elected.

In the 1970s and ’80s, Ard was a short-track master in the vein of stars like Jack Ingram, Harry Gant and Butch Lindley, drivers who could show up at virtually any half-mile track across the country and take home the trophy.

He won the NASCAR Late Model (now the Xfinity Series) championship in 1983 and 1984, scoring 18 wins across those two seasons. He put together four victories in a row late in the 1983 season, winning at South Boston, Virginia; Martinsville, Virginia; Rougemont, North Carolina and Charlotte.

Ard was so dominant in 1984 that he had wrapped up the seasonal championship with two races remaining. In 28 series starts that year, he had 24 top-five finishes and 26 top-10 runs. He won eight times.

In the next-to-last race of the 1984 season, at North Carolina Speedway in Rockingham, Ard suffered critical head injuries when his car slid in fluid from another vehicle and hit the track’s outside wall.

That crash effectively ended Ard’s career and impacted the rest of his life. Ard often talked of learning to walk again as part of his recovery. He said he would use a walker in a pile of sawdust in his backyard so that the landing would be softer when he fell.

Ard eventually was diagnosed with Alzheimer’s disease and Parkinson’s disease. In 2006, responding to Ard’s financial problems, drivers Kyle Busch, Kevin Harvick and Dale Earnhardt Jr., among others, launched a drive to raise funds for his family.

Ard, a native of Scranton, S.C., died in April 2017. He was 78.






Drivers to watch in Cup Series race at Talladega Superspeedway


The NASCAR Cup Series playoffs will reach a critical point Sunday in a 500-mile chase at treacherous Talladega Superspeedway.

The overriding factor in any race at Talladega, NASCAR’s biggest track, is the unknown. With cars running so fast and so close together, multi-car accidents are not only possible but expected, and it’s easy to become the innocent victim of someone else’s mistake.

MORE: NASCAR penalizes William Byron for spinning Denny Hamlin

The tension is doubled for the 12 playoff drivers. A bad finish at Talladega could open the door for a probable playoff exit at the end of the round Oct. 9 at the Charlotte Motor Speedway Roval.

The playoffs to date have seen four wins by non-playoff drivers, an unprecedented result. Tyler Reddick was the most recent to join that list with a win last Sunday at Texas Motor Speedway.

A look at drivers to watch at Talladega:


Denny Hamlin

  • Points position: 6th
  • Last three races: 10th at Texas, 9th at Bristol, 2nd at Kansas
  • Past at Talladega: 2 career wins

Although he hasn’t won, Hamlin has finished in the top 10 in all four playoff races. In the past six races at Talladega, he has four finishes of seventh or better. Now if he can just keep people from running into him…

William Byron

  • Points position: 3rd
  • Last three races: 7th at Texas, 3rd at Bristol, 6th at Kansas
  • Past at Talladega: Best career finish is a second

Byron stands alone as the only playoff driver who has been able to avoid major crashes and trouble in the pits, and he has finished in the top 10 in all four playoff races. After Tuesday’s penalty for his incident with Denny Hamlin at Texas, he sits below the cutline entering Sunday’s race.

Brad Keselowski

  • Points position: 24th
  • Last three races: 8th at Texas, 13th at Bristol, 25th at Kansas
  • Past at Talladega: 6 wins, the active leader

Even in trying times, Keselowski is a threat at Talladega, where he last won in April 2021 (his last Cup victory). He has led 268 laps there in the past 13 races.


Kyle Busch

  • Points position: 15th
  • Last three races: 36th at Texas, 34th at Bristol, 26th at Kansas
  • Past at Talladega: 1 career win, in 2008

Is Busch going to steadily disappear into the mist as he rides out the final weeks of his final year with Joe Gibbs Racing? His best finish in the past four races is 26th. On the positive side this week, he’s the only driver to finish in the top 10 in this year’s three races at Daytona and Talladega.

Chase Elliott

  • Points position: 8th
  • Last three races: 32nd at Texas, 2nd at Bristol, 11th at Kansas
  • Past at Talladega: 1 career win, in 2019

Can Elliott rebound from a fiery finish and a 32nd-place run at Texas? Playoff points give him some comfort, but a second career win at Talladega would be greatly appreciated in the Hendrick camp.

Martin Truex Jr.

  • Points position: 17th
  • Last three races: 31st at Texas, 36th at Bristol, 5th at Kansas
  • Past at Talladega: Best career finish is 5th

Will one of the sport’s most enduring mysteries continue at Talladega? In 70 career starts at Daytona and Talladega, Truex, a former champion and a smooth driver, has zero wins. At Talladega, he has only three top-five finishes in 35 starts.




NBC will broadcast final six NASCAR Cup Series playoff races


The final six races in the chase for the NASCAR Cup Series championship will be televised by NBC.

The races remaining on the schedule are at Talladega Superspeedway (Oct. 2), the Charlotte Motor Speedway Roval (Oct. 9), Las Vegas Motor Speedway (Oct. 16), Homestead-Miami Speedway (Oct. 23), Martinsville Speedway (Oct. 30) and Phoenix Raceway (Nov. 6).

NBC’s broadcasting team will be on hand Sunday for what is typically a seasonal highlight — a 500-mile race at Talladega Superspeedway. The next week the playoffs move on to Charlotte for a cutoff race. The lowest four drivers in the playoff point standings will be eliminated from championship competition.

The Round of 8 is scheduled at Las Vegas, Homestead and Martinsville, with the tiny Martinsville track serving as the final cutoff race. The four drivers who advance from Martinsville will race for the title at Phoenix Nov. 6.

The high drama of the Phoenix race, in which the championship will go to the highest finisher of the four competing drivers, will be carried by both NBC and Peacock.

Post-race commentary and analysis for all six remaining Cup races will be carried on Peacock.

Kyle Larson is the series defending champion. Joey Logano carries the point lead into Sunday’s race at Talladega.

NASCAR viewer’s guide for Talladega Superspeedway


After a messy Sunday at Texas Motor Speedway, the NASCAR Cup Series playoffs move on this weekend to another potentially messy spot — Talladega Superspeedway.

Home to the Big One — an almost certain multi-car crash, Talladega also occasionally produces unexpected winners, including Richard Brickhouse, James Hylton, Lennie Pond, Ron Bouchard and Brad Keselowski.

The mix of tight drafting, the Next Gen car and general playoff tension should make Sunday’s 500-mile run quite the adventure.

On Sunday at Texas, Tyler Reddick became the second driver (after Chase Elliott) to score three wins this season.

Joey Logano enters Talladega with the playoff point lead.

Playoff rookies roll on

The four drivers participating in the Cup playoffs for the first time remain factors approaching the second race in the second round.

Ross Chastain is second in the standings, 18 points above the cutline entering Talladega.

MORE: NBC NASCAR rankings put Denny Hamlin first

Daniel Suarez, Chastain’s Trackhouse Racing teammate, is seventh. He’s four points above the cutline.

Two other playoff rookies — Chase Briscoe and Austin Cindric — will start Talladega below the cutline. Briscoe is four points below the cutline. Cindric is 11 points below the cutline.

Looking for wins

Only six of the remaining 12 playoff drivers have won races at the two remaining tracks in the second round (Talladega and Charlotte Roval).

Among the six, Joey Logano has the best win record at Talladega, having finished first there in 2015, 2016 and 2018.

Other Talladega winners in the group: Ryan Blaney (two), Denny Hamlin (two), Chase Elliott (one), Ross Chastain (one).

The Charlotte Roval is relatively new, of course, but Chase Elliott already owns two wins there. Ryan Blaney and Kyle Larson also have won at the Roval.

An opening for Brad?

Few people who watched it will forget the first Cup Series victory scored by Brad Keselowski.

It occurred at this week’s tour stop — Talladega Superspeedway — in April 2009. Keselowski and Carl Edwards made contact approaching the finish line and notched the win, even as Edwards’ car flew into the frontstretch fence, spraying car parts into the grandstands.

Thirteen years later, Keselowski returns to NASCAR’s biggest track having recorded six Talladega wins. No other active drive has more than three.

Keselowski’s refurbished team — Roush Fenway Keselowski Racing — has new fire with Chris Buescher winning at Bristol and Keselowski winning the pole and finishing eighth at Texas.

RFK Racing has led 309 laps in the past two races, more than the team had led in the prior 105 races combined.

Although he hasn’t won a Cup race since scoring a victory in a Team Penske Ford in April 2021 at Talladega, Keselowski must be considered a threat Sunday.

Entry lists

Thirty-seven drivers, including Xfinity Series star Noah Gragson and reigning Xfinity champion Daniel Hemric, are entered for Sunday’s Cup race.

Talladega Cup entry list

The Xfinity entry list includes 41 drivers for 38 spots. Among those joining the series regulars are Trevor Bayne, Parker Kligerman, Timmy Hill and Jeffrey Earnhardt.

Talladega Xfinity entry list

Forty-one drivers are entered for Saturday’s Camping World Truck Series race. Included are Kaz Grala, Ryan Preece, Natalie Decker, Jennifer Jo Cobb and Parker Kligerman.

Talladega Truck entry list

This week’s schedule and forecast

(All times Eastern)

Friday, Sept. 30

Forecast: Partly cloudy. High of 77. (Weather note: There is the possibility that Hurricane Ian could impact the race weekend, depending on its path).

  • 3:30 – 5 p.m. — Truck Series qualifying
  • 5:30 – 7 p.m. — Xfinity Series qualifying (USA Network)

Saturday, Oct. 1

Forecast: Overcast with showers at times. Potential for heavy rainfall. High of 73. 60% chance of rain.

  • 10:30 a.m. – Noon — Cup Series qualifying (NBC Sports app, Motor Racing Network, Sirius XM NASCAR Radio)
  • 12:30 p.m. — Truck Series race (94 laps, 250 miles; FS1, Motor Racing Network, SiriusXM NASCAR Radio)
  • 4 p.m. — Xfinity Series race (113 laps, 300 miles; USA Network, Motor Racing Network, SiriusXM NASCAR Radio)

Sunday, Oct. 2

Forecast: Sun in the morning, increasing clouds in the afternoon. Slight chance of a shower. High of 74.

  • 2 p.m. — Cup Series race (188 laps, 500 miles; NBC, Motor Racing Network, SiriusXM NASCAR Radio)