Seatbelts. Yup, you gotta use them. They are required by law on the street, and if you’re going to the race track you not only need to wear a seatbelt, you need to wear a minimum of a 5-point harness. This is all for good for a number of reasons. First, it will save your life, no question. Second, the 5-point harness holds you snug in the seat so you can use your appendages to do more important things like steer, heel-toe downshift, and do victory donuts.
Even for amateur weekend motorsports, where a 5-point harness isn’t a requirement, the installation of a harness is a great idea as it increases your safety and allows you to drive faster. Whether you are putting a set in your street car/weekend autocross racer or a full-blown, dedicated track car, there are a few things you need to consider about as you purchase and install the belts.
Harnesses aren’t a terribly expensive upgrade to your car, between $70 and $400 per set, with many options to choose from. The main option differences are a latch/link buckle (where you have to hold five belts together simultaneously to adeptly latch the belt) versus a camlock style (which is much easier to fasten –especially when wearing a helmet, gloves, and HANS device). Both latch systems quickly disengage with a single touch of the buckle, a requirement in case a driver needs to exit a vehicle rapidly. Yup, this usually means fire.
Attaching these belts to your car takes some pre-planning and careful attention to the belt paths as they go over your body and to their fixed point. The easiest way to install a set of harnesses is by using a snap-in system with Grade 8 eye-bolts. One of the advantages of eye-bolts is the belt can rotate on the eye of the bolt and the correct bolt will thread directly into your vehicle’s stock seatbelt anchor location, which by design is the strongest part of the car’s interior.
The sub-belt (the belt that goes right between your legs) won’t have a stock bolt hole that you can utilize to mount it. This will require drilling through the floor pan to install an eye-bolt. This isn’t a big deal for a racecar, but some folks don’t like the idea of making Swiss cheese out of the floor pan of their brand new Mustang (you know, the Mustang the bank still owns). Regardless of your opinion of floor pan damage and resale value, it is crucial that you install the sub-belt because it is the belt that ensures the entire belt system is properly located on your body. You want the lap belts on your lap, not up in your stomach area. If you tighten your shoulder belts and you don’t have a sub-belt installed, inherently your lap belt will ride up and not be position correctly which means: injury to you. This is a bad thing.
If you have a roll cage, a roll bar, or a harness bar, you can simply thread your shoulder harnesses around the bar behind your driver seat and use the three-bar adjuster to get the belt to the correct length and snug. The important thing to remember is the correct threading of the webbing through the three-bar adjuster. There is a method to the madness on how to do this correctly.
I spoke with Ken Myers, owner of I/O Port Racing Supplies, who sells harness systems daily to motorsports enthusiasts, and is a technical inspector for the National Auto Sport Association (NASA). Ken mentioned a few things that right away fail a car during a technical inspection. Cotter pins not placed in the snap-in systems, improper angle on shoulder harnesses (see why this is bad below), and not threading harnesses the correct way are common mistakes during installations.
It is crucial that the belt path from the attachment point in the vehicle (floor pan for lap belt or roll bar for shoulder harness) not be hindered or redirected by the seat prior to going over your body. The forces during an impact are immense and these 3-inch-wide belts are designed to help you withstand an impact. However, if the belt is redirected by a seat, then as the belt straightens out during a crash it can break the seat and then create slack in the belt which means you move forward and your body runs into stuff — hard stuff — like the steering wheel or windshield. Bad for your face.
According to Rick White, co-owner of Autopower Industries, a very critical item to installing any 5-point harness correctly is the angle of the shoulder harness behind the driver. “If the harness is too low (i.e. attached to the floor pan near the rear seat), in a collision the belts will compress the driver’s spine causing injury,” he says. “It is better to have the belts as close to level as possible to the driver’s shoulder height. This is properly done with a harness bar, a roll bar, or roll cage in combination with the seat height.”
To keep the shoulder harnesses from sliding laterally on the roll bar you can use a little bit of roll bar padding to isolate the belts (like the photo above). If you want to get fancy about it, you can install large collars that fit around the roll bar that look pretty slick.
Autopower Industries indicated after the belts expire in two years you could send them back in to have the webbing replaced and the belts re-certified utilizing your existing hardware. This will save you money and keep you safe. Win-win. 5-point harness installation is a worthy upgrade to any performance car as long as it is done correctly. Follow the instructions that come with the belts, improve your lap times and be safe!