How a Driver Walks Away From a 63-G Crash: NASCAR's Safety Cell, Explained
Welcome to the Happy Hour Racing Wednesday Tech Breakdown - where we take one confusing part of NASCAR and make it make sense. No engineering degree required.
The Short Version
In June at Michigan, Christopher Bell took the hardest recorded hit of the Next Gen era and climbed out with a fractured wrist. He was told the impact was 63 Gs. That is not luck. Four systems take a crash apart piece by piece: the wall gives, the car crumples, the seat holds, and the head restraint catches.
A Crash Is About Time, Not Speed
Here is the idea everything else hangs on: speed does not hurt you. Stopping does. How badly it hurts depends almost entirely on how much time you take to stop.
Jump off a chair onto concrete, then onto a mattress. Same height, same speed, wildly different landing. The mattress did not slow you less, it just took longer to do it, and that extra time is what saves your knees.
Engineers measure that in G-force. One G is your normal body weight, so 63 Gs means that for a fraction of a second Bell's body was pushed with 63 times its own weight. Every safety part at a race track exists to stretch that instant out and shave that number down.
Layer 1: The Wall That Gives
That white barrier ringing the track is not just painted concrete. Most of the outside wall at a Cup track is wrapped in a SAFER barrier, short for Steel And Foam Energy Reduction. Engineers at the Midwest Roadside Safety Facility at the University of Nebraska-Lincoln spent about four years developing it, and the first one went up at Indianapolis Motor Speedway in May 2002.
Square steel tubes are welded into a long, smooth skin and strapped in front of the concrete wall. Behind that skin sit bundles of closed-cell foam, the stiff white stuff, stacked like bricks. When a car hits, the steel spreads the load sideways across several feet of wall instead of letting it land in one spot, and the foam squashes flat. That squash is the mattress. It is also why a hard wreck can bring a long red flag: Bell's crash needed 21 minutes of barrier repair.
Layer 2: The Car That Crumples on Purpose
The Next Gen car is built in three bolt-together pieces: a front clip, a center section and a rear clip. The center section is the safety cell. It holds the driver, the seat and the roll cage, and it is meant to keep its shape no matter what. The clips on either end are sacrificial. Their job is to fold up and eat energy so the middle does not have to.
That balance took tuning. When the Next Gen debuted in 2022 the ends were too stiff and drivers were getting hurt in crashes that did not look bad. For 2023 NASCAR softened them on purpose: support bars removed from the rear clip, tubing thinned, connecting bars between the center section and rear clip taken out, and pivot points built in that tell the metal where to fold. A stiffer car looks better after a wreck. A car that folds treats the driver better, and NASCAR picked the driver.
Layer 3: The Seat That Holds You
Inside the safety cell, the driver does not sit in a seat so much as wear one. A modern full containment seat wraps the rib cage and the shoulders, so a side impact pushes on a big area of the body instead of a small one, the same reason a wide backpack strap hurts less than a thin one. Many teams now run carbon fiber seats, which soak up more impact energy than the older aluminum ones.
Around the driver's head are blocks of head surround foam, there to keep the helmet from banging into anything hard when the body whips sideways. A six-point harness pins the driver into all of it, so body and car stop as one object instead of the body continuing on alone.
Layer 4: The Restraint That Catches Your Head
Belts hold your torso. Nothing holds your head, and a helmet makes it heavier. In a hard frontal hit the body stops with the car and the skull keeps traveling, which is how drivers used to die of basilar skull fractures, where the connection between skull and spine pulls apart.
The HANS device fixed that. It is a stiff collar worn on the shoulders under the belts, with two short tethers clipped to the helmet. When the body stops, the tethers go tight and the collar takes the load, so the head slows down with everything else. NASCAR made head-and-neck restraints mandatory in October 2001 and has required the HANS specifically since 2005, one of the clearest before-and-after lines in the sport's history.
What Changed This Season
Bell's Michigan crash on lap 148 is why all of this is being re-examined right now. Chase Elliott broke traction in Turn 3, the contact sent Bell into the Turn 4 wall, and Elliott came back across and caught Bell's left side a second time. NASCAR's Mike Forde confirmed the Delta-v, the measured change in velocity, was the largest of the Next Gen era, and officials called it the hardest hit measured since their current data methodology started in 2015.
What NASCAR did next matters more. Managing director of safety systems Matt Harper and his group reviewed the car at the Joe Gibbs Racing shop the next morning, and what they studied hardest was that head surround foam: how thick, how soft, how it behaved. Bell walked away from the hardest hit on record, so NASCAR wants to know whether his foam spec should become everyone's. Work on head restraints, helmets, seat inserts and seat mounting is ongoing rather than finished.
Thank you to each and everyone who reached out to check on me, I truly feel the love. I'm grateful for my team of doctors, JGR, NASCAR and all of the previous drivers who have helped pave the way for the safety standards in our sport. See you in Pocono!
- Christopher Bell (@CBellRacing) June 9, 2026
What You Will Actually See on Track
Once you know the layers, a wreck reads differently. A nose folded back to the firewall is not a poorly built car, it is the front clip doing its job. Watch how long the safety truck spends at the wall afterward: a long barrier repair means the foam behind the steel crushed and has to be replaced. And when a spotter says a car got hit square in the door, that is the one every driver dreads, because a side impact has the least crush space between the wall and the safety cell.
The Bottom Line
Nothing in racing makes a crash gentle. Every safety system in the sport is doing one thing: buying time, in thousandths of a second, so the force never peaks high enough to break the person inside.
Bell got out of the hardest hit anybody has measured in this car and went back to work. If you ride with a driver like that, rep them. Browse our driver collections and pick up the shirt for the win you actually watched. New tech breakdowns drop every Wednesday, so bookmark the blog and never get lost in the jargon again.
