NASCAR's Scariest Crash of the Year: What Went Wrong With Kyle Larson’s Door Bar Failure

The cabin of a race car can often appear impenetrable, so it can be jarring to see tubing inside of a car move around as we saw in the No. 5 Camaro of Kyle Larson in the NASCAR Cup race at Talladega on Sunday.

Larson was involved in a crash during an overtime restart that sent him down the banking and then bounced him right back up which caused him to be hit on the passenger side of his car by Ryan Preece in the No. 41 Mustang. In the aftermath of the incident, a door bar from the passenger side of Larson’s Camaro had become detached and intruded into the cabin. The crash also left evidence on the composite door panel of where the impact had occurred. The in-car view of Preece’s Mustang shows Larson’s Camaro sliding back up the banking while being inclined on the passenger side, which results in the front end of Preece’s car hitting the passenger side of Larson’s car at angle and the pressure from the hit immediately ejecting the passenger side window.

Once the cars came to a rest, we could see that one of the door bars on Larson’s Camaro had detached from the rest of the structure on the passenger side of that car and intruded into the cabin. Based on the handful of angles shown of the car, this appears to be a middle door bar that is located one slot down from the window opening in the illustration above.

There are likely a variety of factors that played into this bar getting detached. The first element is the angle of impact which resulted in the front of Preece’s car hitting the side of Larson’s car while it was partially up in the air, running into the bottom of those door bars instead of head-on. This appears to have resulted in the door bars and jack post being pushed up and one of the door bars appearing to detach from the rear vertical support. The likely point of detachment is circled in the illustration above.

One of the first things that’s noticeable about that specific door bar is that it does not have a triangular gusset like the bars above and below it, which is likely what resulted in it being easier to detach than the others which likely only got bent. The choice of where to place gussets is likely done based on a simulation on how the whole door bar structure is intended to work and the choice was seemingly made to allow it to deform and dissipate energy based on the most common types of crashes that NASCAR was able to simulate.