How To Build a Road Circuit Race Car - Roll Cage & Bars

Honda Tuning takes you through the ins and outs of assembling a grassroots road/circuit racecar by constructing one for our own sinister ends. Tech ed. Greg Leone performs the buildup, this month going over all the ways to stay alive in the event the worst happens on the track.

When driving down the road doing a typical 80 mph or so, the average person isn't thinking about the laws of physics acting, or waiting to act, upon their vehicle. In fact, most don't really think about how or why they could become injured or killed in the event of a collision. But chew on this: the impact of a car traveling at 40 mph is the same as the force created if it were dropped off of a five-story building. Imagine what an 80-mph impact would do.

Today's production cars are a compromise between comfort/convenience and safety. Most folks don't want to hassle with buckling a five-point harness when they get into their minivan. In the racing environment, though, the odds of being involved in some kind of collision greatly increase. It only makes sense then that every precaution be taken to preserve the life and well being of the drivers.

With safety standards the way they are today, it's rare that a driver is killed even when traveling at speeds in excess of 200 mph. However, safety was not always such a priority. In fact, before the 1950s, helmets were not even mandatory in most organizations. Even as late as 1967 it was rare to find safety restraints in motorsports, and when used the unregulated mounting points would often pull out from their attachments.

With respect to fire protection, in-car fire extinguishers and fire systems were not seen as necessary in the early days of racing. Indeed, they were considered too heavy. The development of fire-resistant material for use as clothing started in the late 1960s, and the first material used was asbestos, but it proved to be notoriously itchy. The next materials used were heat-resistant polymers which included NOMEX, then triple-layer NOMEX, which is still in use today.

Rollover devices (i.e. roll bars, roll cages) and side-impact and side-intrusion restraints were nonexistent in the early days of racing. Many safety devices we take for granted today have been developed at the cost of countless racers' lives dating all the way back to the beginning of motorsports. Even today safety advances and rule regulation changes are credited to the data gathered from recent serious wrecks. Tragedies like Dale Earnhardt's death focused the spotlight on harness, helmet and neck restraint technology. Although unfortunate, it's safe to say Earnhardt and others like him have undoubtedly saved countless lives through their sacrifices.

Care should be taken when planning which safety equipment you're going to use. Be sure to read the rules from the series in which you plan to run. These rules should outline the exact parameters of the equipment needed for competition. How much would it suck to arrive at the track without the proper mounting of the harnesses, or an improper cage design, and not be able to compete? Also, one could easily spend a small fortune on safety equipment, so first buy what fits your budget and the rules, then buy what you feel comfortable using.

Although just a basic six-point cage is mandated for our car, we feel more comfortable racing a car that has extra cross bracing and gussets. You also might want to think about welding on a camera mount, a helmet hook, or any components you might want to add before you paint the car, so that when it's done, it's done right!

After considering all these things it was time for us to pick our arsenal of safety gear. Starting with the rollover protection for the car, we used gussets from the Chassis Shop to add strength to the cage. These are best used where a cross brace cannot be added (i.e. on the inside edges in the passenger compartment of the cage structure).

The fire system we chose is an electrically triggered AFFF foam system, a definite step up from the required 2-pound hand-held system. The SPA Technique system provides far better protection because of the instant deployment and multiple nozzles.

We utilized the Sparco Pro 2000 seat for a number of reasons, mainly its light weight, deep bucket and comfort. Also, a Sparco 3-inch six-point harness will keep the driver on lockdown. A Sparco battery kill switch and window net finish off the car's safety complement.

As for personal battle armor, a Bell M2 FA keeps the dome intact. Although protecting your head is important and mandatory, keeping it cool is almost as important. The M2 FA (Forced Air) has ducting to allow air to be pumped in. Keeping your head cool is one thing, but keeping your head on is quite another. Taking on this task is the HANS device (Head And Neck Support) made by Hubbard/Downing, Inc. An amazing advancement in racing safety, the HANS device works with the harness and keeps your neck from breaking during impact. It's not mandatory but we highly suggest buying a Sparco Tec-5 lightweight three-layer Nomex 3 racing suit if you plan to race. This three-layer suit has good anti-burn technology. For the gauntlets and booties, Sparco Fast Tech gloves and Race-cat Puma/Sparco shoes fill the bill.

[1] First the factory driver seat attachment rails are cut off the body using a grinder. The Sparco seat brackets are attached to the Sparco seat at the lowest setting.
[1] First the factory driver seat attachment rails are cut off the body using a grinder. T
[2] The Sparco seat is then placed in the driver floor area so that we can measure, adjust and mark where the seat will need to be mounted to facilitate the driver. The floor is hammered down to allow the seat to be mounted as low as possible. This will substantially lower the center of gravity.
[2] The Sparco seat is then placed in the driver floor area so that we can measure, adjust
[3] Three pieces of 1.5x1-inch-square tubing are cut and welded together to form a "U" shape.
[3] Three pieces of 1.5x1-inch-square tubing are cut and welded together to form a "U" sha

[4] After assembling the Sparco side mount brackets onto the Sparco Pro 2000, the seat is placed in the driver location and adjustments are made and marked as to the driver's preference.
[4] After assembling the Sparco side mount brackets onto the Sparco Pro 2000, the seat is
[5] Mounting plates are then cut out and welded to the chassis where the corners of the U-frame will mount.
[5] Mounting plates are then cut out and welded to the chassis where the corners of the U-
[6] Afterward, nuts are welded to the U-frame where the Sparco side-mount brackets will bolt. The U-frame is to be welded to the mounting plates. The Sparco side-mount seat brackets are then bolted to the U-bracket.
[6] Afterward, nuts are welded to the U-frame where the Sparco side-mount brackets will bo

[7] Next the Sparco Pro 2000 is bolted to the brackets at its lowest setting.
[8] A bracket needs to extend from the main hoop horizontal cross bar to the seat back and bolt into the seat. We're ready to sit down.
[8] A bracket needs to extend from the main hoop horizontal cross bar to the seat back and
[9] First the Sparco 3-inch six-point harness mounting points are determined. The shoulder straps should be mounted at 90 degrees and a maximum of 40 degrees. This will prevent compression of the spine during an impact.
[9] First the Sparco 3-inch six-point harness mounting points are determined. The shoulder

[10-11] The nut plates are then welded to the chassis. Two are welded behind the seat on each side for the lap belts, and one is welded to the floor in front of the seat for the anti-submarining strap (aka the sixth point).
[10-11] The nut plates are then welded to the chassis. Two are welded behind the seat on e
[11]
[12-13] Eye bolts are then threaded into the nut plates, and the lap belts and sixth strap are clipped into place
[12-13] Eye bolts are then threaded into the nut plates, and the lap belts and sixth strap

[13]
[14-15] The shoulder straps are then wrapped around the horizontal cross bar behind the seat.
[14-15] The shoulder straps are then wrapped around the horizontal cross bar behind the se
[15]

[16] At this point the harness is adjusted to fit the driver.
[17] First the SPA fire bottle location is determined. We chose the right rear of the vehicle, forward of the shock tower, largely because the weight of the bottle and the bracket will help ballast the chassis. The bottle should be mounted in the fore and aft direction.
[17] First the SPA fire bottle location is determined. We chose the right rear of the veh
[18-19] A mounting bracket is then fabricated and welded to the chassis in the section behind the passenger seat.
[18-19] A mounting bracket is then fabricated and welded to the chassis in the section beh

[19]
[20-21] The Decabon tubing (plastic-coated aluminum) is then plumbed in the driver compartment and into the engine compartment. Three nozzles are pointed at the driver and three are pointed at the engine.
[20-21] The Decabon tubing (plastic-coated aluminum) is then plumbed in the driver compart
[21]

[22-23] The nozzles are then attached to the tubing. Each fitting is a press fitting and just needs to be pressed and snapped into place. Also, the nozzles are a bulkhead fitting so they can be mounted to the firewall.
[22-23] The nozzles are then attached to the tubing. Each fitting is a press fitting and j
[23]
[24-25] Next the power pack/control panel is mounted and wires run to the bottle.

[25]
[26-28] The activation buttons are installed. The one with the plastic shroud is mounted within the driver's reach (when seated and strapped in). The second button is mounted to the outside of the vehicle for activation in the event the driver is unconscious.
[26-28] The activation buttons are installed. The one with the plastic shroud is mounted w
[27]

[28]
[29] Strangely enough, window nets don't usually come with mounting brackets. In this case we'll use a spring-loaded bar.
[29] Strangely enough, window nets don't usually come with mounting brackets. In this case
[30] The bracket is welded to the cage where it's out of the way, yet can still be accessed when you're strapped into the driver's seat.
[30] The bracket is welded to the cage where it's out of the way, yet can still be accesse

[31] The lower bar from the kit is replaced with one that's bent and can swing and drop out of the way when in the down position.
[31] The lower bar from the kit is replaced with one that's bent and can swing and drop ou
[32] The Sparco window net is attached to the bars and brackets.
[33] On the driver-side door "X" brace, we wanted a little more protection to prevent intrusion during an impact. A 1-1/2-inch chrome-moly tube is cut in half and notched to fit over the interlinking tubes.
[33] On the driver-side door "X" brace, we wanted a little more protection to prevent intr

[34] This brace is then welded onto the cross bars. This adds strength to the welded section.
[34] This brace is then welded onto the cross bars. This adds strength to the welded secti
[35-36] Chrome-moly gussets are made from plate steel. The steel is cut out, dimple dyed, bent, and welded to the "X." Now we feel safe and comfy.
[35-36] Chrome-moly gussets are made from plate steel. The steel is cut out, dimple dyed,
[36]

[37-38] Lastly, 3/16-inch holes are drilled into a noncrucial area in all of the required tubes in the cage.
[37-38] Lastly, 3/16-inch holes are drilled into a noncrucial area in all of the required
[38]
[39] This is required and should shut off your car completely when switched off. Some switches only have one pull, which means that it controls one circuit at a time. The one we chose has three circuits, one to interrupt the battery, one to interrupt the ignition, and one to ground out any remaining juice from the lines.
[39] This is required and should shut off your car completely when switched off. Some swit

[40-41] We fabricated a box that fits flush with the dash vent and mounted the Sparco switch to it. We then routed all the electrical and flipped the switch.
[40-41] We fabricated a box that fits flush with the dash vent and mounted the Sparco swit
[41]