A lumbar cushion supports...
A lumbar cushion supports the lower back and removes any air gap between you and the seat to minimize injury in the case of an accident.
The head support extends out...
The head support extends out from the sides of the headrest area and is designed to minimize fatigue. It also holds your head in place, slowing its motion during an accident.
Shoulder supports can also...
Shoulder supports can also be bolted on the back of the seat, extending around the shoulders to give you additional support during cornering. It also helps slow your upper bodys motion during a crash.
The leg supports hold your...
The leg supports hold your legs in place, restricting movement while driving and in the event of a crash.
This drawing shows you the...
This drawing shows you the key measurement points. When making your measurements, use a straight edge, not a tape measure. A tape measure will conform to your bodys shape giving a false measurement. A straight edge (yardstick) will show the width of your body as it would be in the seat. Starting with the chest width (A), this measurement should be taken 1-1/2 inches below the armpit. Next, the shoulder height (B) is taken by sitting on a flat surface with your legs hanging over the side. Place the straight edge on the flat surface and measure up to the top of your shoulders. The armpit height (C) is measured the same way as the shoulder height, except you measure up to the armpit. For hip width (D), using the straight edge, measure across the midsection of your hip while sitting on a flat surface. This gives a true hip-width measurement as if you were in the driving seat. The last measurement is chest depth (E). This is done by placing your back flat against a wall and measuring 1-1/2 inches below the armpit from the wall outward.
This photo shows how snug...
This photo shows how snug you should fit in your seat. The hip area and all the way up through the shoulders should not have any gaps. You should feel slight pressure from the seat.
There is a lot more to your racing seat than having a comfortable place from which to race.
Comfort is definitely required to prevent fatigue, but safety is the major concern. How should you fit into the seat and what kind of seat and seat accessories should you have? Circle Track went to Steve Kirkey from Kirkey Racing Fabrication, Inc. to learn more about seat selection, how to fit one to your body and how they can provide you with the best support and protection.
The construction of racing seats can vary from manufacturer to manufacturer and seat style. With any seat, the most important consideration is that it is made with strong, durable material to keep the driver well supported and safe. In an effort to cover most of the racers, we looked at a seatKirkeys 36 Seriesthat is designed for short-track racing from Hobby Stocks up to Late Models, both on dirt and pavement. The 36 Series seat is constructed with 0.125-inch, 5052-grade aluminum and has an aluminum extrusion bead running around the edges to make the seat strong and prevent any sharp spots. The headrest has a reinforced tubular rolled edge and offset aluminum extrusion around the perimeter to increase strength and driver safety.
When the cover was designed, the same effort was used to create good support throughout. A half-inch of high-density polyurethane foam is used throughout the entire seat with one-inch extra padding on the left and right rib areas. The seat features an inner-thigh support designed to keep your legs from flopping around from the g-forces created by normal racing and in the event of an accident.
There are several Kirkey seat accessories designed to keep the driver comfortably supported and safe. Starting at the top of the seat, there are right and left head supports. These supports are designed to help with neck fatigue by holding your head in an upright position. They will also slow your head down during a side impact. The head supports are bolted onto the back of the headrest, wrap around the sides and extend outward about seven to eight inches. The head supports are wrapped in half-inch, high-density polyurethane foam.
Moving down the seat, shoulder supports can be added to keep your body from falling over the side of the seat and increase body support during cornering. They are also bolted onto the back of the seat, wrap around the sides and extend outward seven to eight inches. They should be positioned with the driver in the seat so they fit snug against each shoulder, but not so tight that the driver is unable to move freely. The shoulder supports are wrapped in one inch of high-density polyurethane foam.
The lumbar support is a small piece of foam fitted to the lower seat underneath the cover to give stability and comfort to your lower back. Most of all, it removes any space between your back and the seat. This is critical in an accident because space means your body can move and movement can cause injury. The leg supports are designed to support your legs, minimizing fatigue.
Position them in the car where its comfortable and gives your legs the most support, then bolt the support onto the side of the seat. If you look at the picture of our seat, the upholstery is cut back so the supports can be added quite easily. The cover can be removed and attached at will. The leg supports are bolted to the sides of the seat and are wrapped with an inch of high-density polyurethane foam.
Fitting the seat to your body When buying a seat, the most important step is getting one designed for the type of racing youre doing and one that fits your body. If there is extra room between you and the seat, then you have the ability to slide around. This gives you less support and increases the chances of injury.
How do you pick the correct-sized seat? First, you start by measuring your body. The most important measurement is hip width from side to side. Take this measurement while sitting on a bench in your full racing suit with your legs hanging over the side and measure through the centerline of the body. This is the biggest part of your body and where all the weight is in the seat. Fitting a seat in this manner is similar to buying a pair of shoes: you need to be snug in the seat, not too tight but not too loose. You should feel pressure on your hips. Next, measure the shoulders, width of chest, height of your armpit, chest depth, driver height and weight. You should fit into the seat the same way in these locations as the hips: snug with a little pressure.
Make sure the seat youre sitting in is properly sized for you, Kirkey says. A lot of guys buy a used car and they just sit in the seat that comes with it, Nine times out of 10, its not the right seat. Be aware of some older seats. A seat, over time, will fatigue just like any other part. It may not be visual, but the aluminum will fatigue after just normal use. When youre buying a used car or if the car you have has a seat thats more than three or four years old, its time to buy a new one.
In the event of an accident, Kirkey said replacement of the seat is a judgment call. If the seat is just bent slightly, no more than a half-inch or so, and you can spring it back in shape, you dont need to replace it. But, if the seat is in any way deformed beyond a half-inch, pulled away from its mounting bolts, the rib supports been opened up straight or the leg support is opened up straight, then the seat has done its job and its time for a new one.
As in anything to do with racing, safety should always come first. If youre a driver, then the seat is your office chair, the place youll be spending the majority of your time. Selecting the proper seat and making sure it is as safe as possible is the primary building block toward cockpit safety.