NASCAR: Christopher Bell crash hardest hit in at least a decade

Christopher Bell's crash on Lap 148 of the NASCAR Cup Series at Michigan International Speedway was the hardest hit in the four plus years of the NextGen car.

The incident occurred when Chase Elliott lost traction over a bump in Turn 3 and slid up into Bell while racing for second. The contact sent Bell into the wall, the impact resulting in a 21-minute SAFER Barrier repair, but also a secondary shot as Elliott came back up the track into the left side of Bell’s car.

In the latest episode of the official NASCAR Hauler Talk podcast, communications exec Mike Forde said Bell’s impact was the worst since that car debuted in 2022, but also the worst back to 2015 when Matt Harper, NASCAR’s managing director of safety systems, joined the company and collected data using his methodologies.

This crash was measured in delta-v which is a measure of change in velocity.

“Delta-v is a measure of speed lost in an incident,” said Forde. “So if you’re going 200 mph and then you hit a wall and scrub off X amount of speed, that difference is what the Delta-v is. I can't give you the Delta-v number for Bell. That data is proprietary, in a sense. We share that with the team and the driver and that’s their data to do what they want.” But we can confirm it was the biggest we’ve seen in the Next Gen era.”

So how is delta v different from impact in GS? "Forde asked both Harper and vice president of safety engineering John Patalak for an explanation.

Patalak: Well, it's complicated but... a G is a unit of acceleration. It's better to talk about acceleration than G. Acceleration is how quickly something's velocity changes. You can come off a stop sign on I-85 in five seconds and have a peak of five G and a Delta V, which is a change of velocity, of 60 miles an hour. Or you can hit a wall and go from 60 to 0 in .1 second and peak at 50 G. It's the same delta-v. Both are significant. Acceleration is important because mass x acceleration = force .

Harper: And we usually call out the peak G too. It's not a constant load through the crash, just the highest value. Which is also important because if you talk about peak G, that number may seem massive, but when you’re talking about injury potential, it’s the length of time you are at a high G level.

Patalak: You can have a really big G peak but if you don’t have a descent Delta-v it’s not injurious or interesting.

NASCAR also has told Joe Gibbs Racing what those numbers were, both the Gs and the Delta-v, but it’s up to the team and Bell to release that publicly. On Monday morning at 9 a.m., the Sanctioning Body also visited the JGR shop to complete a safety review of the car.

NASCAR also did an immediate walk through of the car right after the crash, but also the SAFER Barrier before repairing it.

Bell has a fractured left wrist and undisclosed ankle injuries, but his doctor has cleared him to race this weekend at Pocono Raceway."He had to go back to his doctors for a follow up appointment," Forde said. “Once we got the clearance from them, we would then clear him to race ... and he has received that clearance. ...So what that looks like is Christopher will visit his personal physicians, that physician will work with our medical team to clear him so that clearance does come from his doctors and they have to be board certified and so on and so forth, the right credentials. "They work with us and say 'we checked him out and we feel comfortable that he can be in the race car' and once we get the clearance from them, then we give him the clearance.

Harper led the Monday morning safety review at JGR.

“There’s a big emphasis being put around the head surround foam,” said Forde. “We just keep adding to this part of the rule book as we learn more and more. So important is the thickness of the head surround. And because we were happy with the way the head surround helped Christopher in this incident, we did a lot of measuring of the type of foam he used, the softness and the thickness. We want to see, 'Hey, is this kind of the magic number? Is this something other drivers should look into? This was the biggest hit we’ve ever seen in the Next Gen era, and all in all, Christopher came out of it pretty well. So that’s one of the things we’re going to be looking at going forward.”

NASCAR's director of track services, Chase Brashears, also joined the podcast to talk about the immediate safety protocols.