Roll Bar Safety
Since I have a long background in chassis building & a lot of real world crash experience where people lived & died ... I figured I'd chime in with some advice & guidance. To make this official, I need a soapbox to stand on.
In my driver development program, we lived, breathed, taught, practiced & required safety. If one of those young drivers had been disabled or died on my watch, I don’t think I could live with myself. I required HANS devices & have full containment seats before the racing sanctioning bodies did.
We required a 3-layer nomex suit with a fire rating of TPP # of 21 or greater. There are a LOT of BRANDS with suits that test below 21. In addition, we required nomex or Carbon-X underwear long johns, long sleeve under shirts & socks. (Carbon-X is best)
My young drivers personally commited they would protect themselves, as a promise to me. One driver showed up at the track without his fire retardant underwear. No Nomex/Carbon-X … no driving my race cars. “Aw Ron, but it’s just practice. I’ll have it on tomorrow for the race.” Not no … but hell no. He ran & bought some Carbon-X underwear & made the last half of practice.
I have lost friends because they were “just”. They were just practicing, just playing around, just testing. Cars, guard rails, cliffs & concrete barriers don’t know you’re just playing, just practicing, just testing, etc. A drag racing friend died in 1985 doing a private test. He had his helmet & 5-point harness on … but not fully tight … because they were just testing. But when a car flips & crashes … the forces don’t know you were you “Just …”
I had a young driver, hit the concrete wall on a practice day at a ½ mile track when I wasn't there. He was hurt & bruised bad, but otherwise ok. Some of the injuries suggested he wasn’t wearing his HANS. He wasn’t … and I dropped him from my program. He broke his promise to me to be smart & protect himself in this dangerous sport.
I’ve been on fire, been upside down at 177 mph, hit walls so hard I’m lucky to be alive & broke my back in 1991 … almost didn’t walk again. This stuff is serious. If you’re going to build your car to be more like a race car … and drive it in race situations … then plan for race level safety measures. The sport of Pro Touring … where drivers compete in AutoX, real road courses & fast events like the Silver State Challenge … are just asking for someone to get killed or disabled … because there are less rules.
Don’t let the lack of rules guide your safety.
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In my drag race chassis building business, we had a funny … but true … phrase we’d use. We built our cars to win races … and protect the driver. We called our additional safety procedures “our client retention program” … and with a bit of tongue-in-cheek-humor, we would tell prospective clients, “if you crash one of our race cars & live … you may buy another one. But if you crash & die … you won’t be buying any cars.”
We built our cars with methods that took more time & money, but protected the driver. We didn’t allow the customer to choose parts if they affected safety. All of this safety was “built into the cost” and wasn’t “optional” to the customer. If they didn’t want to spend the money for our level of car & safety, they weren’t our kind of customer.
Don’t want anyone dying on my watch … and I have seen too many people die … including a prospective customer who went somewhere else because we wouldn’t use his homemade fuel cell. Another chassis builder did build a car with it.
The fire didn’t kill him … when he went through the guard rail at Green Valley Raceway in Ft Worth, Texas. The fuel cell ruptured & broke free, allowing fuel to go forward in the cockpit. He died 4 days later in the hospital from pneumonia … which is common with severe burn victims.
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Alright, I’ll get off my soapbox and share some safety stuff with you …
Roll Bars
A. A 4-point roll bar with plates bolted to or welded to thin sheet metal in unibody type cars … adds a very small level of protection. I believe more to satisfy insurance companies than to protect the driver. Car owners add them thinking they are getting a degree of safety that really doesn’t exist … and then have a false sense of security when driving in races, or race like conditions.
B. A 4-point roll bar that mounts to actual frame structure, does offers a higher degree of crush protection in the event of a roll over or impact to the roof.
C. The more footprint points the roll bar or cage has, the stronger it will be. The more of these points that actually connect to frame structure, the stronger it will be.
D. A 4-point roll bar with 2 extra struts that connect the main hoop to the subframe connectors in unibody type cars, makes a difference.
Look at the red bars in the attached photo at the bottom of this post.
E. A 4-point roll bar with 2 extra connector struts … with the 2 rear bars attaching to real rear subframe … is significantly better.
F. A 4-point roll bar with 2 extra connector struts … with the 2 rear bars attaching to real rear subframe … in an X-brace fashion … is substantially better.
G. Building a 6-point roll bar with 4 rearward bars … 2 straight & 2 in an X-brace … both attaching to real frame … is as good as you can build without adding door bars or a cage. There are various designs. I think some are safer than others.
H. Door bars are one the best additions you can add to a roll bar for safety & performance … if you don’t mount them too low. It supports the roll bar from “folding” with the added bonus of strengthening the chassis for improved* performance. *Maybe a discussion for another thread sometime.
I. An added bonus, if you didn’t mount them so low they’re worthless, is door bars add protection in side impacts, when someone runs a red light & crashes into your door, or the passenger door where your loved ones ride.
J. For Pete’s sake … don’t install a roll bar so close to the driver’s or passenger’s head … that they hit it in an impact … UNLESS you are ALWAYS going to wear a helmet … including on the street. Guys have died from moderate wrecks on city streets, when their unprotected head hit the roll bar and split their head open. In those type of typical auto wrecks, they would have been better off to have no roll bar. Please don’t use this as an excuse to not have one. Just install it with this in mind.
Material Matters:
K. Most roll bars & cages are made with inexpensive seam welded mild steel. Mild steel grades commonly vary from 1010 to 1030. The higher the number, the stronger it is. Most seam welded tubing commonly available is 1010 or 1012, the cheapest with the least strength. But 1018 is available, for slightly more money, if you look for it. Buying a roll bar … ask the manufacturer what they use.
L. DOM stands for drawn over mandrel. It is a better process for manufacturing round tubing, working with the grain of the steel & leaving no weak seam. It is still mild steel … but because the process costs more, manufacturers use higher grades ... typically 1018 to 1026. Most stock car cages are made from this. A small percentage are made with chromoly. Because of the constant crashes & repairs in oval track racing, these racers & chassis builders like that the mild steel DOM bends easily creating localized crush zones. Personally, I don’t want a roll bar over my head as a crush zone.
M. Stainless steel tubing is similar in strength to DOM mild steel. In racing, we use it on bumpers & nerf bars that we WANT to bend on impact. We use stainless, instead of DOM, only so we don’t need to paint it or chrome it. We tig weld it & bolt it on.
N. 4130 Chromoly is the strongest option of commonly available & affordable tubing materials. OMG! Chromoly is SO MUCH STRONGER than mild steel, DOM or stainless steel … it’s hard to compare them. NHRA understands this & requires mild steel bars to be 1-3/4” x .134” wall or 4130 Chromoly at 1-5/8” x .083” wall … and the Chromoly is STILL STRONGER. All pro level drag cars are made from Chromoly for this reason. Chromoly is so strong, that often when a car wrecks, instead of crushing, it spreads the load over the whole car … and therefore the entire chassis “bows.”
Roll Cages:
O. When you up your game to a well designed roll cage with 8, 10, 12 or 46 points, you just increased the safety factor by triple, and the chassis rigidity too. Again, in unibody type cars, you will want it to connect to real frame structure as much as possible. The increase in torsional rigidity ... and the performance gains make this a double win.
P. The optimum set up, is to make the cage out of Chromoly for the best driver & passenger protection … and make the front & rear bars out of DOM for crush zones in the event of front or rear impacts.
Other safety components:
Q. If you guys want to discuss any of this, I’d be happy to share with you insight on fire extinguisher systems, full containment seats, head & neck supports, suits, helmets, etc. Let me know.
As the Watch Commander used to say on Hill Street Blues, "Be safe out there."
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