Side skirts have been the center of multiple controversies in NASCAR for several seasons, but a NASCAR-mandated construction change could limit the attention this year.
On Cup Series cars in 2018, the fender component will be made of composite material (the same being used for Xfinity Series bodies) instead of steel.
The change is intended to ensure that side skirts will hold their original shape unlike the steel side skits that could be deformed. Bending or flaring out a side skirt in front of the rear tire can provide more downforce and sideforce.
NASCAR outlawed the practice of intentionally modifying side skirts in 2015 after teams regularly manipulated the steel part during pit stops. But it still was possible to have a side skirt become flared out because of contact with the asphalt, which could result in a performance advantage (but without drawing a penalty; it’s believed there were no penalties for side skirt modifications last season).
The switch to a composite side skirt should reduce the potential for side skirts to be altered in a significant way.
Appeal panel gives William Byron his 25 points back
The National Motorsports Appeals Panel stated that Byron violated the rule but amended the penalty to no loss of driver and owner points while increasing the fine to $100,000.
The panel did not give a reason for its decision. NASCAR cannot appeal the panel’s decision.
The panel consisted of Hunter Nickell, a former TV executive, Dale Pinilis, track operator of Bowman Gray Stadium and Kevin Whitaker, owner of Greenville-Pickens Speedway.
Here is the updated standings heading into Sunday’s race at the Roval:
Byron’s actions took place after the caution waved at Lap 269 for Martin Truex Jr.’s crash. As Hamlin slowed, Byron closed and hit him in the rear.
Byron admitted after the race that the contact was intentional, although he didn’t mean to wreck Hamlin. Byron was upset with how Hamlin raced him on Lap 262. Byron felt Hamlin forced him into the wall as they exited Turn 2 side-by-side. Byron expressed his displeasure during the caution.
“I felt like he ran me out of race track off of (Turn) 2 and had really hard contact with the wall,” Byron said. “Felt like the toe link was definitely bent, luckily not fully broken. We were able to continue.
“A lot of times that kind of damage is going to ruin your race, especially that hard. I totally understand running somebody close and making a little bit of contact, but that was pretty massive.”
On the retaliatory hit, Byron said: “I didn’t mean to spin him out. That definitely wasn’t what I intended to do. I meant to bump him a little bit and show my displeasure and unfortunately, it happened the way it did. Obviously, when he was spinning out, I was like ‘I didn’t mean to do this,’ but I was definitely frustrated.”
The 13 drivers who will participate in the Advance Auto Part Drive for Diversity Combine were revealed Thursday and range in age from 13-19.
The NASCAR Drive for Diversity Development Program was created in 2004 to develop and train ethnically diverse and female drivers both on and off the track. Cup drivers Bubba Wallace, Daniel Suarez and Kyle Larson came through the program.
The 2020 and 2021 combines were canceled due to the impact of COVID-19.
“We are thrilled that we are in a position to return to an in-person evaluation for this year’s Advance Auto Parts Drive for Diversity Combine,” Rev Racing CEO Max Seigel said in a statement. “We are energized by the high-level of participating athletes and look forward to building the best driver class for 2023. As an organization, we have never been more positioned for success and future growth.”
The youngest drivers are Quinn Davis and Nathan Lyons, who are both 13 years old.
The group includes 17-year-old Andrés Pérez de Lara, who finished seventh in his ARCA Menards Series debut in the Sept. 15 race at Bristol Motor Speedway.
Also among those invited to the combine is 15-year old Katie Hettinger, who will make her ARCA Menards Series West debut Oct.. 14 at the Las Vegas Bullring. She’s also scheduled to compete in the ARCA West season finale Nov. 4 at Phoenix Raceway.
The three most crucial parameters in determining the severity of a crash are:
How much kinetic energy the car carries
How long the collision takes
The angle at which the car hits
The last of these factors requires trigonometry to explain properly. You can probably intuit, however, that a shallower hit is preferable to a head-on — or rear-on — hit.
When the angle between the car and the wall is small, most of the driver’s momentum starts and remains in the direction parallel to the wall. The car experiences a small change in velocity.
The larger the angle, the larger the change in perpendicular speed and the more force experienced. NASCAR has noted that more crashes this season have had greater angles than in the past.
Busch and Bowman both had pretty large-angle hits, so we’ll skip the trig.
Energy — in pounds of TNT
A car’s kinetic energy depends on how much it weighs and how fast it’s going. But the relationship between kinetic energy and speed is not linear: It’s quadratic. That means going twice as fast gives you fourtimes more kinetic energy.
The graph shows the kinetic energies of different kinds of race cars at different speeds. To give you an idea of how much energy we’re talking about, I expressed the kinetic energy in terms of equivalent pounds of TNT.
A Next Gen car going 180 mph has the same kinetic energy as is stored in almost three pounds of TNT.
Because IndyCars are about half the weight of NASCAR’s Next Gen car, an IndyCar has about half the kinetic energy of a Next Gen car when both travel at the same speed.
At 330 mph, Top Fuel drag racers carry the equivalent of six pounds of TNT in kinetic energy.
All of a car’s kinetic energy must be transformed to other types of energy when the car slows or stops. NASCAR states that more crashes are occurring at higher closing speeds, which means more kinetic energy.
Longer collisions > shorter collisions
That seems counterintuitive, doesn’t it? Who wants to be in a crash any longer than necessary?
But the longer a collision takes, the more time there is to transform kinetic energy.
A pitting car starts slowing down well below it reaches its pit box. The car’s kinetic energy is transformed into heat energy (brakes and rotors warming), light energy (glowing rotors), and even sound energy (tires squealing).
The same amount of kinetic energy must be transformed in a collision — but much faster. In addition to heat, light and sound, energy is transformed via the car spinning and parts deforming or breaking. (This video about Michael McDowell’s 2008 Texas qualifying crash goes into more detail.)
The force a collision produces depends on how long the car takes to stop. Compare the force from your seat belt when you slow down at a stop sign to what you feel if you have to suddenly slam on the brakes.
To give you an idea of how fast collisions can be, the initial wall impact in the crash that killed Dale Earnhardt Sr. lasted only eight-hundredths (0.08) of a second.
SAFER barriers use a car’s kinetic energy to move a heavy steel wall and crush pieces of energy-absorbing foam. That extracts energy from the car, plus the barrier extends the collision time.
The disadvantage is that a car with lower kinetic energy won’t move the barrier. Then it’s just like running into a solid wall.
That’s the same problem the Next Gen car seems to have.
Chassis stiffness: A Goldilocks problem
The Next Gen chassis is a five-piece, bolt-together car skeleton, as shown below.
That graphic doesn’t show another important safety feature: the energy absorbing foam that covers the outside of the bumpers. It’s purple in the next diagram.
All cars are designed so that the strongest part of the car surrounds the occupants. Race cars are no different.
The center section of the Next Gen chassis is made from stout steel tubing and sheet metal. Components become progressively weaker as you move away from the cockpit. The bumper, for example, is made of aluminum alloy rather than steel. The goal is transforming all the kinetic energy before it reaches the driver.
Because the Next Gen car issues are with rear impacts, I’ve expanded and highlighted the last two pieces of the chassis.
The bumper and the rear clip don’t break easily enough. The rear ends of Gen-6 cars were much more damaged than the Next Gen car after similar impacts.
If your initial thought is “Just weaken the struts,” you’ve got good instincts. However, there are two challenges.
I highlighted the first one in red: the fuel cell. About the only thing worse than a hard collision is a hard collision and a fire.
The other challenge is that a chassis is a holistic structure: It’s not like each piece does one thing independent of all the other pieces. Changing one element to help soften rear collisions might make other types of collisions harder.
Chassis are so complex that engineers must use finite-element-analysis computer programs to predict their behavior. These programs are analogous to (and just as complicated as) the computational fluid dynamics programs aerodynamicists use.
Progress takes time
An under-discussed complication was noted by John Patalak, managing director of safety engineering for NASCAR. He told NBC Sports’ Dustin Long in July that he was surprised by the rear-end crash stiffness.
The Next Gen car’s crash data looked similar to that from the Gen-6 car, but the data didn’t match the drivers’ experiences. Before addressing the car, his team had to understand the disparity in the two sets of data.
They performed a real-world crash test on a new configuration Wednesday. These tests are complex and expensive: You don’t do them until you’re pretty confident what you’ve changed will make a significant difference.
But even if the test goes exactly as predicted, they aren’t done.
NASCAR Cup Series drivers race on the road for the final time this season Sunday, as the Charlotte Motor Speedway Roval course ends the playoffs’ Round of 12.
The 17-turn, 2.28-mile course incorporating the CMS oval and infield will determine the eight drivers who will advance to the next round of the playoffs. Chase Elliott won last Sunday at Talladega Superspeedway and is the only driver who has qualified for a spot in the Round of 8.