A well-designed racing cockpit is a system that takes into account all aspects of driver s
No racer thinks a wreck is in his or her future, but it happens far too often. So many drivers get odd injuries that could have been prevented. Taking a thoughtful and careful look around the cockpit allows any racer to improve his or her safety. Follow along and learn about how a better understanding of your environment can help you survive a crash.
The seat should be mounted to the rollcage or a structural member of the frame. It is always better to use manufacturer-supplied mounting rails, because they are specially built for your seat. They properly mount the bottom front and bottom rear of the seat. Seat rails should be bolted to the seat with Grade 8 3/8-inch bolts, heavy-duty large flat washers, and lock nuts. The bolts must be spaced as far apart as possible to properly distribute the load.
The seat should be tied into the horizontal tubing that runs behind the seat. Instead of bolting through the tubing, it is better for strength purposes to weld on a bracket and then bolt through that. The bolts should be vertical so that they are in shear.
A bracket that supports the entire width of the seat is best. Spreading the load provides a more secure mounting. A minimum of four Grade 8 5/16-inch bolts, heavy-duty flat washers, and lock nuts spaced as wide as the width of the seat should be used. Again, a manufacturer-supplied bracket should be used whenever possible to connect the seat, the rear bar, and the mounting flange.
The seat system must protect and support the areas shown in the boxes in order to ensure a
In an accident, one of the first areas of the car that your body hits is the door bar. This large area is very close to the seat and well within reach of your swinging arms. Roll bar padding on these bars help, but you can still slide between the bars. Most teams use full-sheet door pads. This is a piece of fire-retardant material that has an impact-dissipating foam laminated to the back of it.
A driver's safety in the cockpit has a lot to do with the quality, mounting, and care of the seatbelts. We have discussed these topics in previous articles, but they can never be mentioned enough. There are a few concepts to think about when buying, installing, and using seatbelts.
1. Better belt materials: In the early days of racing, seatbelts were made from the same thing that military belts were made from, which was cotton webbing. As technology advanced, it was found that nylon was a better choice for longer life and higher strength. In the last 5-10 years, polyester and combinations of materials have made their way into the market of competition seatbelts.
The seat must be mounted firmly to the rollcage structure. Here is a mock-up of a Sprint C
These materials have been preferred because of the small amount of stretch compared to the average nylon stretch numbers, but this should not rule out all nylon belts. There are quality nylon belts on the market, and the price difference between nylon and polyester does not always gain the stretch advantage for the price a racer is paying.
2. Keeping the belts as short as possible: As we just mentioned, all belt webbing stretches. The amount the belt stretches is a function of the tension load placed on it and the length of the belt this tension is applied to. The more the belt stretches, the farther the driver moves in the seat and the greater the likelihood of injury. Shorter belts lessen the stretch.
3. No sternum straps: When they were first developed, sternum straps were used to keep the shoulder belts closer to the middle of the chest and keep them from sliding off the shoulders. What has been found since then is that these straps are neck injuries waiting to happen.
As the driver's torso moves forward in a frontal impact, the shoulders slide on the belts and the sternum strap moves toward the neck. There is no fix for this. Proper mounting and the use of short belt lengths will accomplish the goal of keeping the belts on the driver's chest.
This car has two head nets that further prevent movement of the head during violent crashe
4. Proper mounting angles and hardware: The SFI Foundation has an article on its Web site (www.sfifoundation.com) detailing proper belt mounting methods, angles, and procedures. There are other articles and diagrams on the Web, but SFI's site has such a wealth of safety knowledge that it is worth the look.
5. Certifications and age: Any quality belt system has a certification tag. This is the manufacturer stating that the belt meets the minimum standards set forth by a certifying foundation under a certain specification. Most belts in America, and quality belts from overseas, have an SFI tag. The belt should also have a tag that states its date of manufacture. It is commonly held that a set of belts should not be used more than two years after its date of manufacture.
The legs make up the largest mass of the body that is unrestrained. During an accident, the driver's legs are free to hit anything from the transmission tunnel and shifter handle on the right side of the cockpit to the door bars on the left. To control the driver's leg motions, it is important to utilize leg braces and a steering column mounted knee knocker.
The leg braces are run from the front of the seat on the sides of the legs to the front firewall, or as far forward as reasonable. The braces should be made from a substantial aluminum. The edges of the braces should be bent over, not only for strength, but also to eliminate another opportunity for the driver to be cut.
Door padding is gaining popularity. This item is now offered by Longacre Racing Products.
If there is room, a knee knocker should be installed under the steering column or toward the front of the seat. Both options work well, but still consider that this should not be mounted absolutely rigid. Unlike the leg braces, the knee knocker is designed to keep the knees apart and slow down the motion of the legs. If the knee knocker is mounted absolutely rigid, the leg can wrap around it and create injuries.
Below the dashboard, the only things to stop the driver's feet are the pedals. The pedals need to be mounted solidly to the chassis, and the pedal faces themselves need to be thick enough so as not to slice into the driver's foot or leg if the leg were swung that way in the event of an accident. A thin pedal face is lighter, but it can act like a knife blade when the side of a driver's shoe makes high-speed contact.
Head nets have become a visual staple in many series of motorsports. They first appeared as an additional way to control the motion of the head and arms inside Sprint Cars. They were then utilized in the stock car realm for protection of the driver's head. They were used for the right side excursion of the head when the passenger side of the car impacted the wall.
This carbon-fiber composite seat is used in the Nextel Cup Series. Notice the long leg sup
The common window net provides little protection for the head contacting the track wall in a left-side impact. The addition of the left-side head net provides an extra barrier. However, with the advent of seat-mounted head surrounds, the need for the head net is reduced.
Some seat builders question the use of these head nets when adequate head surrounds are utilized. There is no question of their usefulness when there is no head surround or when a short head surround is used. Short head surrounds are put in some cars because of space limitations in the cockpit. They allow for ease of driver exit.
One industry expert theorized that the correct use of these head nets in conjunction with a head surround could help limit the deflection of the head surround in an accident. To our knowledge, no test results have been published in this regard.
The most complete research related to head nets was done a few years ago by Tom Gideon of GM Racing and published in an SAE paper (#2004-01-3513) titled "Race Car Nets for the Control of Neck Forces in Side Impacts." This paper looks at right-side head nets and their placement and usage in controlling head-and-neck loading during a frontal right-side impact.
Gideon begins by discussing the situations that require the use of these nets. In short, whether a driver wears a HANS Device, a Hutchens Device, or some other head-and-neck system, in the event of a side impact, all of these devices have, at best, only limited control over sideways head movement. In these types of accidents, if a seat-mounted head support system is not in place, only the head nets provide protection for the head.
The head net must be mounted correctly in order to properly control the energy in a side i
Gideon ran 16 sled tests at a 50g pulse. Various seats, net designs, and impact angles of 45, 60, and 90 degrees were tested. It is important to note that none of the tests utilized a seat-mounted head support system. Some very interesting conclusions can be drawn from the results.
1. As compared to the control test done without a net, the right-side nets were shown to reduce neck force and head acceleration at all crash angles tested.
2. Gideon found that net geometry and placement in relation to the seat and driver is important. The lower strand should be oriented to support the load of the shoulder. The upper strand should pass along the center of the helmet when viewed from the side. This is the preferred placement because Gideon found that if the upper strand of the net is above the center of gravity (CG) of the helmet, neck compression forces increase. If the upper strand is below the CG of the helmet, neck tension increases.
Head nets were first mounted in a stock car on the right side to control head movement fro
3. Nets should be designed with consideration of the car, seat and driver.
4. In a non-reinforced seat with no head surround system, it is better to have a net.
5. Right-side nets were tested, but there is no reason to think that left-side nets wouldn't function with similar positive results in left-side impacts.
6. The next level involves testing how the nets can be used in conjunction with a head surround to make up for the limitations of specific cockpits.
The days of using a stripped down passenger car to race professionally have been over for a while. Each Nextel Cup race car is now a purpose-built vehicle that has systems and infrastructure built in to enhance safety. This is not true of the common stock class series in which the race team must carefully provide a design that is safe. When designing the cockpit of your race vehicle, it is so important to look at the mounting of each accessory that goes into the car in regard to what may happen to that piece if you are involved in a wreck.
It was discovered that the window net on the left side did not adequately control head mov
One of the main areas of concern is the mounting of the tachometer. This is an accessory that is often attached using hose clamps. Anything added beyond the normal parts of the interior and rollcage should be bolted to a rollbar with bolts that sustain it in case of a wreck. Other cockpit accessories that are commonly mounted incorrectly include the coil, the on-board computer, the radio, the drink bottle, and the fire extinguisher. Once the basics of cockpit safety are reviewed, it is time to look at more advanced levels of safety.
The most basic racing seatbelt system is the five-point system with two shoulder belts, two lap belts, and a submarine belt. To gain additional body control, the five-point system can be changed by replacing the single sub belt with two individual belts to control the motions of each leg. This system is called the six-point harness.
The six-point harness system is a vast improvement in body control compared to the five-point, but there is still another way to increase a driver's body control. In the typical six-point system, the leg belts snake through a loop in the lap belt and hook into the shoulder belts. This belt arrangement puts an odd angle on the direction of force for the tightening of the shoulder belts.
Advanced cockpit designs offer very strong support brackets to reduce flex in the head sur
One way to keep the benefits of the leg control of the six points and keep the belts in an optimum alignment is to add the single sub belt so that the shoulder belts pull against it. This belt system is offered by many manufacturers.
Seat foam molds are used to fill the void between the driver and all parts of the seat. This spreads the impact loads over a larger area of the driver's body to reduce the unit loading. There are two types of foam molds.
The most popular mold has foam that expands inside a plastic bag while the driver is in the seat. The foam expands into the void areas, surrounds the driver, and then hardens. It is normally covered with a protective fabric.
The second type of foam mold is the polystyrene bead mold, which is created by fitting a bag of polystyrene beads into the seat, and having the driver sit in it. All the excess air is sucked from the bag, and a resin is inserted to bind the beads together. When the resin hardens, the driver is removed and the polystyrene beads are fixed in place. This type is most popular in Indy racing. Both methods allow the impact loads to be spread over a larger area of the driver's body.
This Super Late Model cockpit has all of the adjusters, the MSD box, and the fire bottle s
On the subject of seat foam molds, it is important to understand that foam molds are not substitutes for high-quality seats or correct seat design. Some have suggested that the combination of non-rib seats and foam molds may provide adequate protection for the ribs, lower back, and spine support. However, on-track result do not support this suggestion. There is no substitute for a quality seat, and a seat foam mold is only an addition to a safety system and not a band-aid for lesser designed safety products.
The following statement is from noted racing physician Dr. Terry Trammell: "Safety is not a driver's right; it is a driver's responsibility." It is important to understand that just like your race engine, your safety equipment is a system in itself. Any addition to your safety program must not only consist of high-quality products, but also must fit well into your overall safety system.
By Bob Bolles
We spoke with Randy LaJoie, who manufactures racing seats and systems for stock cars. He agrees with the information presented in this article and adds that it is very important for the seat components to be rigid in order to properly protect the driver in all crash situations. We thought, like many others, that some flexing of the seat and head supports might absorb some of the energy in a crash. But we didn't consider the other consequences, such as secondary impacts and their effects on the driver if the seat components are bent out of place. According to LaJoie, "No driver has ever been hurt by the seat not moving."
If a seat bends upon impact, then it no longer fits the driver snugly. From that moment on, the driver is sitting in a seat that does not securely fit his or her torso, and that translates into a lot of movement and possible injury in a secondary impact.
If the head support bends away in an impact, then the head has farther to go to reach the support in a second or third impact. Contact with the rollcage or track wall is now possible, not to mention possible neck fractures, whereas a rigid support will keep on locating the head where it should be in relation to the body. To prevent serious injury, all of the body (head, chest, and hips) must stay in line upon impact. Modern race seats make that happen. We thought it necessary to clarify this point.