How To Build A Safer Car

Published by Mike on June 6, 2017

Tips From The Experts

Everyone in the business of race car safety will tell you that there is no such thing as a completely safe race car. Race cars are designed to go as fast as possible within the limits of the applicable sanctioning rules and the laws of nature. There is and will always be danger that come with that whole scenario. What we can do is try to make our cars as safe as possible and hope for the best. We can always have a safe-er race car.

While there have always been fatal accidents in racing, there are certain periods in history where the death rate was higher. The 1980’s in Northeast modified racing saw quite a few fatalities until someone caught on that the front frame rails were way too stiff. Although I don’t know the exact cause of death in each instance, one can assume that Basilar Skull fracture was associated with many of those because of the many fatal head-on impacts involved.

The years 1999 through 2001 saw numerous driver fatalities from impacts with concrete walls. The most well-known involved Dale Earnhardt, Sr. That one event caused the ground to shake in every racing community, stock car especially. Most will agree that Dale’s tragic end was the catalyst that served to saved many lives since. Nearly every sanction and track now requires head and neck restraints and many tracks now have soft walls installed.

Looking back at the possible causes of the problem, there was a reason why all of a sudden, drivers were not able to withstand the force of impact for each of these periods. Something changed along the way that caused the impacts to affect the driver more severely. Reviewing those changes, and ones still taking place, is how we learn how to do things better.

The Chassis Becomes Stiffer – From approximately 1995 on, the teams and car builders continued to make changes to reduce the amount of flex in the chassis. The primary part of the cars that presented the biggest flex problems was the right front corner. As time went on, the right front corner became stiffer. The problem we are faced with is that in many cases, the first part of the car to contact the concrete wall is the right front of the car.

Brain injuries started to appear in the period between 1997 and 1999 when we saw several well-known drivers suffer serious brain related injuries. The problems associated with the stiff chassis were beginning to show on a scale that was definitely noticeable. Then in 1999, teams were allowed to increase the wall thickness in the tubing that is a part of the front of the chassis. This further increased the stiffness of the front ends. It is obvious, with the tragedies we have seen, that today, the excessive amount of G-force transmitted to the driver’s bodies make crashes more possible to cause injuries.

The Modern Era Of Safety – In the time since 2001, we might have suffered more deaths in stockcar racing as well as other forms of automobile racing had events not unfolded like they did. Everyone inside and outside the sport of auto racing had come to realize that something needed to be done to make this sport safer for the drivers. And they did.

Before 2001, talk centered on soft walls. Most of the talk about making stock car racing safer had been centered on designing a soft wall technology and virtually no one was mentioning the construction of the cars as a possible cause until it was pointed out that the cars had become very stiff. There was no longer a crush zone to reduce the G-forces.

The driver’s physical weak point is the neck, and particularly the base of the skull. That is the only part of the body that holds the head from moving forward. In sudden deceleration, the tendons and muscles are not strong enough to counter those huge forces and they break. When they do, massive damage is done to the spine and base of the brain causing death.

Starting in the late 1980’s and continuing today, Head and Neck restraints are being developed by several companies to assist in controlling the violent forward motion of the head in a crash. The use of head and neck restraints has become almost the norm among drivers. Because of that, we have almost eliminated basilar skull injuries among those drivers who wear the devises.

And so, we have tended to get away from any study or concern with the construction of the race cars themselves. Since we no longer are seeing deaths in racing from frontal impacts alone, the talk about stiff cars has died down. But we are still seeing concussions happening, the most talked about being Dale, Jr.’s struggle with that condition.

It is now believed that a stiff chassis could contribute to more than the Basilar Skull injuries. Drivers having concussions while using the head and neck restraints tells us that we are not done with research and re-design of the cars. Let’s look a little farther.

Racing Seats Evolve – The seat the driver sits in has undergone many changes over the years. Containment has become the key word and focus among major seat makers in the racing marketplace. It has been proven that if we can contain the body and head from moving around and hitting things inside, and outside, of the car, we can help the driver survive major crashes.

So, the surround type of seat has evolved and now we have hip, rib, shoulder, leg and head side restraints. We had already solved the frontal impact problems and now we can concentrate on the side impacts. Just to note here, rear impact injuries have never been a real problem and were basically eliminated once high back seats were utilized many years ago.

The side head restraints did solve the problem of the head moving too far in a side impact. With sprint car type of roll over crashes where the side of the car impacts the ground repeatedly and violently, it became necessary to keep the head centrally located.

Now we have reports of racers having problems with concussions that might be associated with these side head supports. One racer has claimed that he had symptoms of concussion from racing on a rough dirt track and not hitting anything. The only thing possible as a cause is the head striking the side restraints.

A New Kind Of Concussion – It is believed by some in the industry that the head hitting the side restraints is in and of itself causing concussions. If that were true, then maybe we need to re-evaluate how these restraints are being constructed.

In the early days of race seats when the early designs of side head restraints were introduced, there was a single layer of aluminum covered by a thin, soft foam piece. When a racer impacted in a side movement, the head and helmet hit the restraint and usually bent it out away from the seat in the direction of the impact. This is commonly called dissipation of energy.

Afterwards, the racer could either send the seat back for repair, or as was usually the case, did the repair himself by bending the aluminum back into place. I’m sure that part of the seat could take only so many repairs until it broke off. But in any event, it slowed the side motion of the head in a side impact and helped prevent neck injury.

It was also not strong enough to cause a concussion, not like we are seeing today. The top seat makers today are making these side head restraints very stiff so that they will not bend. In doing so, they are definitely transmitting more of the side impact forces to the brain. It is a direct result of limiting the motion.

The top builders of racing seats are also using layered and progressive stiffness foam in the side-head restraints. This cushions the movement and keeps the head from slamming into the stiff restraint. This has helped reduce the incidence of concussions. And they have recommendations for mounting them.

I was told by several top seat makers representatives that the drivers helmet should not be more than ¾ inch from the head restraint on both sides. This keeps the head from moving too far and “bouncing” around inside the two restraints on either side of the helmet. The farther the head moves until it contacts the restraint, the more damage that can be done.

I was also told that in the Nascar rules for the Cup cars, the seats are mandated to use stiff foam only. With the higher speeds these cars go and the possibility for high G-force side impacts, they need the stiff foam. That being said, could that be a factor in reports from Cup drivers about getting concussions? I don’t really know where else to look.

Looking At The Whole Picture – Many factors need to be addressed when considering the design of the cars as they relate to injuries. As we add structure and components to the cars in order to assist in dissipation of energy on impact, we need to also consider the effects each change has on the way the way the cars are setup and how those changes will affect the performance of the cars. For example, when building crush factors into the front of the car, adding weight to the front of the car affects the weight distribution, which directly affects the handling and the way we setup the cars.

If we decide to raise the frame rail on the front of the cars to increase the angles formed by the tubing, we might alter the geometric layout that is so critical for camber control and roll center location. These two effects play a significant role in allowing the front tires to work the way they should. Correct designs for front geometry have evolved over many years and we don’t need to destroy all of that work by overreacting.

If we cannot change the structure of the car, we can at least look at the area around the driver to see if anything can be done here to help with what we are seeing in today’s racing. It seems that the seat and restraints are really the only area left to focus on logically.

Crush Zones are Needed – Stockcars, as well as drivers, need crush zones. Stockcars have traditionally not been designed with distinct crush zones. The crush zones should be built into areas of the car that have a good chance of coming in high-speed contact with the wall or other obstructions. The crush zones should collapse in a controlled way in order to slow the car and extend the time it takes to stop the car.

In the same way, restraints for the driver should maybe crush too. Helmets are constructed of crushable material that gives way when the head hits something hard. This material is “used up” so to speak because that material does not return to its former shape to help with future impacts. The helmet then needs to be re-built with new material after each crash.

If we re-designed the side head restraint to use the same material that is used in the helmet, we would be no worse than the actual helmet in protecting the head. But that is not practical for routine bumping of the head. It is the repeated lower impacts from rough tracks and lower level crashes that seems to take a toll.

Is it possible to do away with the side head restraints? Could a new design of head and neck restraint be produced that would not only protect against frontal impacts, but side impacts too? They could be made to allow movement of the head a certain distance before coming into play, just like the current design of H&N restraints. Then we would eliminate the bumping of the head on the fairly stiff side restraints.

It is evident that this situation with the current forms of concussion needs to be studied and solutions derived to eliminate this injury. After taking care of the big problems, it seems like we are zeroing in on the smaller, but nonetheless important details.

Conclusion – The sanctioning bodies and track officials for all of stockcar racing need to be continually aware of safety issues that come up in our sport. They need to fully understand how we have come to certain points, how important it is to quickly evaluate their own particular safety rules and then put together a list of changes that will be responsible and effective. If they can do that, then once all is said and done, the types of injuries we have seen and are still seeing will be reduced and/or eliminated.

Do your individual part by buying and using a quality head and neck restraint, a modern, well designed seat, a highly rated fire suit and racing approved helmet. Above all, race with a car where all of the parts are built to dissipate energy in a hard crash. Let your car builder know that you are concerned about your safety. Create your safe-er environment today.