Drag Race 101: Roll Bars, Cages, Harnesses and More


I’ve been a fan of drag racing in all its forms since the early Seventies. I’ve seen the likes of Big Daddy Don Garlits, Kenny Bernstein, Shirley Muldowney, John Force and many others, both live and on TV. I’ve seen hundreds of events. In fact, I’m a fan of motorsports, period, whether it’s stock cars, Formula 1, sports cars or our beloved drag racing. One thing that ties them all together is that they’re dangerous. People have died and been seriously injured pursuing our sport. That’s why, if you have a passion for the sport, you need to learn now how to be safe.

Use the Minimum Requirements as a Beginning

The minimum safety requirements for each of the amateur and professional classes and brackets have already been discussed. I’m not going to talk about all of them here. This article is going to be about things that are designed to keep the car from crushing around you and to restrain you inside the compartment in the event of a catastrophic event. I’m going to talk about the difference between a roll bar and a roll cage, and then the various kinds of each. Next point of interest will be the types of seats, and finally seat belts/safety harnesses.

Roll Bars Don’t Prove Enough Protection for Me

A roll bar is usually a section of metal tubing bent into a squared U-shape with the open end bolted or welded to the floor of the car. These are usually placed immediately behind the front seat(s) to protect the driver (front seat passengers) in the event of a roll-over accident.

The problem is, they only provide maximum protection if the vehicle rolls over perfectly level and this rarely happens. Usually, the front of the vehicle rolls lower than the back causing the roof to crush unequally and onto anyone in the front. They also provide almost no protection from side impacts. When properly installed, they do provide a solid base for other passive restraint systems.

Nerf Bars versus Full Bars

Roll cars come in two flavors: Nerf bars and full bars. Nerf bars are only behind the seat(s). They are U-shaped and upside-down, but they only cover the area immediately behind the head and headrest of the seat. Typically they stick up about three to four inches above the head of the occupant, although some are only two inches of the seat and extend about three inches on either side of their head. If there are two seats in the car, there will be two Nerf bars. Manufacturers used to commonly install Nerf bars in two-door roadster convertibles.

Roll bars extend across the width of the vehicle. One side is bolted or welded the floor just to the outside of the front seats. The cross bar rises to just under the roof of the car and follows the contour of the roof as it meets the door pillars at the sides.

Roll Cages Provide the Most Safety in a Catastrophic Wreck

A full multi-point roll cage on a construction jig. The roll cage is built out of rolled tubing while the jog is constructed of square tubing. This image perfectly shows the cocoon of safety created by a well-designed roll cage.

Roll Cages provide a huge step forward in safety for the driver of a race car. Roll cages range from the most basic to extremely intricate. Like roll bars, they are constructed of sections of tubing bent into certain shapes designed to keep a driver safe in the event of a wreck. The most basic of roll cages adds another upside-down U with a set of tubes connecting it to the roll bar. The back part of this roll cage sits behind the (front) seat(s) while the front part is right behind the windshield with the connecting tubes forming a roof of sorts over the front seat passenger(s).

There are numerous variations of this basic roll cage design. Some cages have three braces extending between the front and rear legs while others have more or less. Some have lateral braces at shoulder and/or hip level on the sides to provide more side impact protect. Still others are designed so these side braces can be removed to ease entry and exit from the vehicle. Others still have the front legs follow the contour of the dash of the car instead of being perfectly straight. These are all called four-point roll cages.

This is an example of a roll cage custom-designed for a single seat racer. This particular one is for a Baja racer, but closely resembles what can be found in purpose-built dragsters.

Some four point cages are designed with cross pieces at the top and bottom of the windshield. This works to keep the windshield opening from crushing or distorting in a wreck. This gives you an extra way to exit the car if it’s on its side or roof.

The Faster You Go the More Protection You Need

Not every roll-over wreck has you rolling sideways-door-roof-door-wheels, etc. Sometimes you go end over end. Even worse, sometimes one roll will launch your car a few feet into the air and have it crashing down on the bumper, either straight down or at an angle, causing more front to rear crushing damage to the car and passenger compartment. If you’re building a car that’s going to be a sub-eight-second slammer, you should start thinking of having more brace points for your cage.

I mentioned in the NHRA rules and regulations article that every race car I built got at least a five-point cage. These consisted of the roll bar behind the front seats, with the front legs following the windshield closely and the legs following the contour of the dash to maximize leg well protection. The rear brace also had a brace in the middle, providing protection from angled impacts from above.

For faster cars I would install modified six-point roll cages, with the sixth point branching out from the front brace in the middle of the windshield and bracing below the dash. The front legs would extend straight down from the top of the windshield and meet the floorpan/frame. Extending at an angle to in front of the leg well would be an extra set of braces.

Rhino bars, bars at shoulder and hip level to the outside of the seats provide added protection to occupants in the event of side impacts. Once you reach a certain level of competition, these will be a requirement, but at most amateur levels they aren’t, although they’re mandatory for me no matter what. Because they make getting in and out of the car quite difficult, I typically weld the bottom ones in and make the ones at shoulder level so I can bolt them in and out quickly and still maintain maximum protection.

Put Tails on Your Cage

Eight point roll cages wrap you in a cocoon of safety. These add two more legs extending to the rear of the passenger compartment, usually just behind where the back seats would be. There are also nine point cages that have a middle leg between the seats. These rear legs are bolted and/or welded to the frame side rails and rear cross member.

Protection can be enhanced by running connecting tubes from the middle legs to the rear legs. These can be just a single tube, either straight or at an angle from top to bottom (or vice versa) or they can be a big X, or a web.

Most eight and nine point cages will extend the area of the roof that’s protected from crushing in a roll-over wreck. They also provide increased protection from another hazard that is pretty unique to drag racing-objects falling through the roof. Super-charged/blown engines running large amounts of boost and compression plus nitromethane have been known to blow their tops. What I mean by this is that even with the engine safety precautions, the occasional engine’s blower has been known to be launch a dozen or more feet in the air when something really bad happens to the engine. The blower has to come down somewhere, so extra crossmembers and support are added to the top of eight and nine point cages.

Where to Plant It: Comfort or Safety?
821-8000SSome of the seats found in modern day performance cars are very well suited for the drag racer. Sure, they’re comfortable and usually quite adjustable. They’re in performance cars, so they’re also most likely solid enough and contoured to provide excellent support and stability while barreling down the track. Older cars, even muscle cars? Not so much. If you’re building a strip burning drag racer out of anything less than say 15 years, you’re going to need to consider upgrading the seating arrangements.

Although there were a few alternatives, back when I first started building cars Recaro was the only name to know in performance seating. They had a few different seats, but their best one was the one that you had to measure your body and send them the results so they could hand craft it to fit you perfectly. These seats fit you and you fit them like a glove. You were comfortable and had excellent lateral stability. More importantly, the seats provided an excellent level of safety and enhanced the safety effects of the other safety systems used.

Racers today have a number of choices in high performance racing seats. Recaro is still out there, but Sparco is now the brand most racers use. Procar, TMI, Simpson, and Roush Racing are other well-known names in the industry. You could also go completely custom and have a local racing/performance fabrication shop help you build one for your measurements.

Get Properly Belted

Cars come from the factory with a seatbelts that are quick and easy to secure. These are called three point restraints in that they are connected to the car at three points: On either side of your hip and above your shoulder. These are fine for every day driving. They’re even legal for a few NHRA classes and brackets. However, they really don’t hold you snugly in your seat, you’ve got too much room to wiggle and slide. Another problem is that they can be difficult to release if there’s any tension on the belt.


You need racing seat belts, racing or safety harnesses. These are also classified by the number of points at which they attach to the car. Basic racing harnesses are four point harnesses with two lap belts and two shoulder belts. Five point harnesses provide what is known as anti-submarining protection. Submarining is when the force at your which your forward velocity is reduced causes your body to want to slide forward and down. Five point harness have a belt that attaches to the car in front of the seat. Six point harnesses have two belts providing this protection, with one belt restraining each leg, angling towards the front of the car and attached to a central strap (see image below).

Building a really high performance passive restraint system for your strip burner will entail thinking of the seat and the harnesses at the same time. The seats I like the most are designed so that the harnesses are threaded through openings in the seat placed so as to more properly conform to my body’s dimensions. For example, openings in the seat back one or two inches above my shoulders, allowing me to be held more snugly on the vertical axis. Side slits in the seat will house the lap belts, contouring them more closely to my hips, forcing my buttocks into the bottom of the seat. You get the picture.

Five and six-point harnesses provide maximum protection.

Some racers weld or bolt the harness attachment points to the body of their car. Not me. I prefer to weld bolts to the roll cage and attach the belts to the cage. One bar runs between the center legs at should height and is the shoulder belt attachment point while another runs across the floor and is where the lap belts attach. Anti-submarine belts, when used, attach to the side posts or rhino bars.

This Sabelt eight-point safety harness incorporates arm straps with the shoulder straps and works with a HANS device.

One area that many people forget is hand and arm safety. I had a friend tell me once that he’d just hold onto the steering wheel in a wreck so his arms would be Ok. They weren’t. Arm restraints keep your arms from flailing about like a puppet with the strings cut in a wreck. They attach to your arms and the (usually) the lap belt(s) to keep your arms restrained. They can keep your hand safe inside in a wreck if you’re not using a window net. They can also keep your hands from flying and hitting the roll bar.

Protect Your Neck

The HANS Device can save your live and is mandatory at some levels of NHRA racing.

Dale Earnhardt Sr. died in a NASCAR race when he slammed headfirst into a retaining wall at Daytona International Raceway. His shoulder and lap restraints worked too well. While his body was properly restrained in his seat during the collision, his head and neck weren’t, they kept going a little beyond the normal range of motion. This caused his neck to hyperextend, causing what’s known as a basilar skull fracture. Immediately following Dale’s crash, NASCAR mandated the HANS device, something many other sanctioning bodies had already mandated.

The HANS device is a restraint system that slides over your shoulders, usually under your safety harness. There is a U-shaped frame that slides over your shoulders. Attached to this frame are two clips that attach to your helmet, keeping your head from snapping forward in a collision.

About Mike Aguilar 388 Articles
Mike's love of cars began in the early 1970's when his father started taking him to his Chevron service station. He's done pretty much everything in the automotive aftermarket from gas station island attendant, parts counter, mechanic, and new and used sales. Mike also has experience in the amateur ranks of many of racing's sanctioning bodies.

Be the first to comment

Leave a Reply

Your email address will not be published.


I agree to receive emails from RacingJunk.com. I understand that I can unsubscribe at any time. Privacy Policy
Copyright © 2005-2020 MH Sub I, LLC dba Internet Brands
All Rights Reserved.

Internet Brands