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.


NASCAR announces rule changes for 2023 season


CONCORD, N.C. — NASCAR announced a series of rule changes for the 2023 season that includes outlawing the move Ross Chastain made at Martinsville and eliminating stage breaks at all six Cup road course events.

NASCAR announced the changes in a session with reporters Tuesday at the NASCAR R&D Center.

Among new things for this season:

  • Updated penalty for a wheel coming off a car.
  • Change to the amount of time teams have to repair cars on pit road via the Damaged Vehicle Policy.
  • Change to playoff eligibility for drivers.
  • Cars could run in wet weather conditions on short ovals.
  • Expansion of the restart zone on a trial basis.
  • Choose rule will be in place for more races.

MORE: Ranking top 10 moments at the Clash

NASCAR updated its policy on a loose wheel. Previously, if a wheel came off a car during an event, it would be a four-race suspension for the crew chief and two pit crew members. That has changed this year.

If a wheel comes off a car while the vehicle is still on pit road, the vehicle restarts at the tail end of the field. If a wheel comes off a vehicle while it is on pit road under green-flag conditions, it is a pass-thru penalty.

The rule changes once a vehicle has left pit road and loses a wheel.

Any vehicle that loses a wheel on the track will be penalized two laps and have two pit crew members suspended for two races. The suspensions will go to those most responsible for the wheel coming off. This change takes away a suspension to the crew chief. The policy is the same for Cup, Xfinity and Trucks.

With some pit crew members working multiple series, the suspension is only for that series. So, if a pit crew member is suspended two races in the Xfinity Series for a wheel coming off, they can still work the Cup race the following day.

The Damaged Vehicle Policy clock will be 7 minutes this season. It had been six minutes last year and was increased to 10 minutes during the playoffs. After talking with teams, NASCAR has settled on seven minutes for teams to make repairs on pit road or be eliminated. Teams can replace toe links on pit road but not control arms. Teams also are not permitted to have specialized repair tools in the pits.

NASCAR will have a wet weather package for select oval tracks: the Clash at the Los Angeles Memorial Coliseum, Lucas Oil Raceway Park, Martinsville, Milwaukee, New Hampshire, North Wilkesboro, Phoenix and Richmond.

Elton Sawyer, senior vice president of competition for NASCAR, said that teams have been told to show up at these events prepared for wet weather conditions as they would at a road course. That includes having a windshield wiper. Wet weather tires will be available. 

“Our goal here is to get back to racing as soon as possible,” Swayer said. “… If there’s an opportunity for us to get some cars or trucks on the racetrack and speed up that (track-drying) process and we can get back to racing, that’s what our goal is. We don’t want to be racing in full-blown rain (at those tracks) and we’ve got spray like we would on a road course.”

NASCAR stated that it is removing the requirement that a winning driver be in the top 30 in points in Cup or top 20 in Xfinity or Trucks to become eligible for the playoffs. As long as a driver is competing full-time — or has a waiver for the races they missed, a win will make them playoff eligible.

With the consultation of drivers, NASCAR is expanding the restart zone to give the leader more room to take off. NASCAR said it will evaluate if to keep this in place after the Atlanta race in March.

NASCAR stated the choose rule will be in effect for superspeedways and dirt races.

NASCAR eliminates stage breaks for Cup road course events

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CONCORD, N.C. — NASCAR will do away with stage breaks in all six Cup road course races and select Xfinity and Truck races this season, but teams will continue to score stage points. 

NASCAR announced the change Tuesday in a session with reporters at the NASCAR R&D Center. 

MORE: NASCAR outlaws Ross Chastain Martinsville move

NASCAR stated there will be no stage breaks in the Cup road course events at Circuit of the Americas (March 26), Sonoma (June 11), Chicago street course (July 2), Indianapolis road course (Aug. 13), Watkins Glen (Aug. 20) and Charlotte Roval (Oct. 8).

There will be no stage breaks for Xfinity races at Circuit of the Americas (March 25), Sonoma (June 10), Chicago street course (July 1), Indianapolis road course (Aug. 12), Watkins Glen (Aug. 19) and Charlotte Roval (Oct. 7).

There will be no stage breaks for the Craftsman Truck Series race at Circuit of the Americas (March 25).

In those races, stage points will be awarded on a designated lap, but there will be no green-and-checkered flag and the racing will continue.

The only road course events that will have stage breaks will be Xfinity standalone races at Portland (June 3) and Road America (July 29) and the Truck standalone race at Mid-Ohio (July 8). Those events will keep stage breaks because they have non-live pit stops — where the field comes down pit road together and positions cannot be gained or lost provided the stop is completed in the prescribed time by NASCAR.

NASCAR has faced questions from fans and competitors about stage breaks during road course races because those breaks alter strategy in a more defined manner than on most ovals.

Elton Sawyer, senior vice president of competition for NASCAR, said the move away from stage breaks at road courses was made in collaboration with teams and response from fans.

“When we introduced stage racing … we took an element of strategy away from the event,” Sawyer. “Felt this (change) would bring some new storylines (in an event).”

NASCAR instituted stage breaks and stage points for the 2017 season and has kept the system in place since. NASCAR awards a playoff point to the stage winner along with 10 points. The top 10 at the end of a stage score points.

It wasn’t uncommon for many teams to elect to pit before the first stage in a road course race and eschew points to put themselves in better track position for the final two stages. By pitting early, they would be behind those who stayed out to collect the stage points. At the stage break, those who had yet to pit would do so, allowing those who stopped before the break to leapfrog back to the front.

NASCAR outlaws Ross Chastain Martinsville move

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CONCORD, N.C. —  NASCAR announced Tuesday that it will not permit drivers to run against the wall to gain speed as Ross Chastain did in last year’s Martinsville Cup playoff race.

NASCAR made the announcement in a session with reporters Tuesday at the NASCAR R&D Center.

MORE: NASCAR eliminates stage breaks for Cup road course events 

MORE: NASCAR announces rule changes for 2023

Chastain drove into the Turn 3 wall and rode it around the track at higher speed than the rest of the field, passing five cars in the final two turns to gain enough spots to make the championship race. NASCAR allowed the move to stand even though some competitors had asked for a rule change leading into the season finale at Phoenix last year.

NASCAR is not adding a rule but stressed that Rule covers such situations.

That rule states: “Safety is a top priority for NASCAR and NEM. Therefore, any violations deemed to compromise the safety of an Event or otherwise pose a dangerous risk to the safety of Competitors, Officials, spectators, or others are treated with the highest degree of seriousness. Safety violations will be handled on a case-by-case basis.”

NASCAR stated that the penalty for such a maneuver would be a lap or time penalty.

Chastain said he’s fine with being known for that move, which will never be repeated in NASCAR history.

“I’m proud that I’ve been able to make a wave that will continue beyond just 2022 or just beyond me,” Chastain told NBC Sports earlier this month about the move’s legacy. “There will be probably a day that people will learn about me because of that, and I’m good with that. I’m proud of it.

“I don’t think it will ever happen again. I don’t think it will ever pay the reward that it paid off for us that it did that day. I hope I’m around in 35 years to answer someone’s question about it. And I probably still won’t have a good answer on why it worked.”

The video of Chastain’s wall-hugging maneuver had 12.5 million views on the NBC Sports TikTok account within a week of it happening. Excluding the Olympics, the only other video that had had more views on the NBC Sports TikTok account to that point in 2022 was Rich Strike’s historic Kentucky Derby win. 

Formula 1 drivers Fernando Alonso, Pierre Gasly and Daniel Ricciardo all praised Chastain’s move at the time, joining a chorus of competitors throughout social media. 

NASCAR Power Rankings: 10 historic moments in the Clash


NASCAR’s preseason non-points race, now known as the Busch Light Clash at the Coliseum, was born in 1979 with the idea of testing the sport’s fastest drivers and cars on one of racing’s fastest tracks — Daytona International Speedway.

The concept was driver vs. driver and car vs. car. No pit stops. Twenty laps (50 miles) on the Daytona oval, with speed and drafting skills the only factors in victory.

Originally, the field was made up of pole winners from the previous Cup season. In theory, this put the “fastest” drivers in the Clash field, and it also served as incentive for teams to approach qualifying with a bit more intensity. A spot in the Clash the next season meant extra dollars in the bank.

The race has evolved in crazy directions over the years, and no more so than last year when it was moved from its forever headquarters, the Daytona track, to a purpose-built short track inside the Los Angeles Memorial Coliseum.

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Over the decades, virtually everything about the race changed in one way or another, including the race length, eligibility requirements, format, calendar dates, sponsorship and title. From 1979-2020, the race was held on Daytona’s 2.5-mile oval and served as a sort of preview piece for the Daytona 500, scheduled a week later. In 2021, it moved to Daytona’s road course before departing for the West Coast last season.

Here’s a look at 10 historic moments in the history of the Clash:

NASCAR Power Rankings

1. 2022 — Few races have been as anticipated as last year’s Clash at the Coliseum. After decades in Daytona Beach, NASCAR flipped the script in a big way and with a big gamble, putting its top drivers and cars on a tiny temporary track inside a football stadium. Joey Logano won, but that was almost a secondary fact. The race was a roaring success, opening the door for NASCAR to ponder similar projects.

2. 2008 — How would Dale Earnhardt Jr. handle his move from Dale Earnhardt Inc. to Hendrick Motorsports? The answer came quickly — in his first race. Junior led 46 of the 70 laps in winning what then was called the Budweiser Shootout, his debut for Hendrick. The biggest action occurred prior to the race in practice as Tony Stewart and Kurt Busch tangled on — and off — the track. Both were called to the NASCAR trailer, where the incident reportedly accelerated. Both received six-race probations.

3. 2012 — One of the closest finishes in the history of the Clash occurred in a race that produced a rarity — Jeff Gordon’s car on its roof. Kyle Busch and Gordon made contact in Turn 4 on lap 74, sending Gordon into the wall, into a long slide and onto his roof. A caution sent the 80-lap race into overtime. Tony Stewart had the lead on the final lap, but Kyle Busch passed him as they roared down the trioval, winning the race by .013 of a second.

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4. 1984 — A race that stands out in Ricky Rudd’s career, and not in a fun way. Neil Bonnett won the sixth Clash, but the video highlights from the day center on Rudd’s 15th-lap crash. He lost control of his car in Turn 4 and turned sideways. As Rudd’s car left the track, it lifted off the surface and began a series of flips before landing on its wheels, very badly damaged. Safety crews removed Rudd from the car. He suffered a concussion, and his eyes were swollen such that he had to have them taped open so he could race a few days later in a Daytona 500 qualifier.

5. 1980 — The second Clash was won by Dale Earnhardt, one of Daytona International Speedway’s masters. This time he won in unusual circumstances. An Automobile Racing Club of America race often shared the race day with the Clash, and that was the case in 1980. The ARCA race start was delayed by weather, however, putting NASCAR and track officials in a difficult spot with the featured Clash also on the schedule and daylight running out. Officials made the unusual decision of stopping the ARCA race to allow the Clash to run on national television. After Earnhardt collected the Clash trophy, the ARCA race concluded.

6. 1994 — Twenty-two-year-old Jeff Gordon gave a hint of what was to come in his career by winning the 1994 Clash. Gordon would score his first Cup point win later that year in the Coca-Cola 600 at Charlotte, but he also dazzled in the Clash, making a slick three-wide move off Turn 2 with two laps to go to get by Dale Earnhardt and Ernie Irvan. He held on to win the race.

7. 2006 — Upstart newcomer Denny Hamlin became the first rookie to win the Clash. Tony Stewart, Hamlin’s Joe Gibbs Racing teammate, had the lead with four laps to go, but a caution stacked the field and sent the race into overtime. Hamlin fired past Stewart, who had issues at Daytona throughout his career, on the restart and won the race.

8. 2004 — This one became the duel of the Dales. Dale Jarrett passed Dale Earnhardt on the final lap to win by .157 of a second. It was the only lap Jarrett led in the two-segment, 70-lap race.

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9. 1979 — The first Clash, designed by Anheuser-Busch to promote its Busch beer brand, drew a lot of attention because of its short length (20 laps) and its big payout ($50,000 to the winner). That paycheck looks small compared to the present, but it was a huge sum in 1979 and made the Clash one of the richest per-mile races in the world. Although the Clash field would be expanded in numerous ways over the years, the first race was limited to Cup pole winners from the previous season. Only nine drivers competed. Buddy Baker, almost always fast at Daytona, led 18 of the 20 laps and won by about a car length over Darrell Waltrip. The race took only 15 minutes.

10. 2020 — This seemed to be the Clash that nobody would win. Several huge accidents in the closing miles decimated the field. On the final restart, only six cars were in contention for the victory. Erik Jones, whose car had major front-end damage from his involvement in one of the accidents, won the race with help from Joe Gibbs Racing teammate Denny Hamlin, who was one lap down in another damaged car but drafted behind Jones to push him to the win.