By on May 29, 2010

What is that car? Some of you will figure it out immediately, while the rest will want to sneak a peek at the end of this article. Regardless of the make and model, here’s what it is: it’s a race car that competes in an entry-level ARCA series. No longer street legal. Not even close. Since it’s a race car, it uses (some) racing safety equipment. That’s all well and good. There’s a problem, however. In the past couple of years, I’ve seen more and more drivers incorporating “harness bars”, four-or-five-point belts, and other racing-style accessories in their street/trackday cars. Those people are risking their lives, and if you’re one of them, you should keep reading.

As trackday drivers progress into the intermediate level, they start to notice a few things about the interface between (wo)man and machine in a street car. To begin with, most of us sit much too far away from the steering wheel when we’re on the street. This is the standard test: Sit all the way back in your seat, with your shoulders resting firmly on the seatback. Now stick your right arm out and lay on the top of the steering wheel. Where on your arm does the wheel make contact? For most street drivers, the answer will be “the ends of my fingers, maybe.” That’s bad news. Move your seat and seatback forward until it’s your wrist that touches the top of the steering wheel with your arm straight out.

This puts you a lot closer to the wheel. How close? Well, here I am behind the wheel of the Mystery Car, which is now revealed by its windshield banner to be a Mystery Rental Car. Surely you’ll figure it out now, but note that I have about a 90-degree bend in my arms when I am grasping the wheel.

Yes, that’s an Omega Speedmaster “Broad Arrow” I’m wearing. Thanks for asking. Even this close to the wheel, however, we face another problem with car control. Most street cars can generate 1g or more on a racetrack. The Audi R8 I tested at MSR Houston two years ago generated transitional g-forces of 1.18g during a 90-mph entry to a corner. This is more sideways force than I would encounter if the driver’s seat were mounted sideways on a wall and I was trying to sit in it. No wonder, then, that during fast driving we find ourselves sliding around in the seat a lot.

Heavy braking produces a similar effect, and not all inertia-reel seatbelts will hold us in the seat when it happens. This means we can’t use our left foot to brake. We have to use it to press against the floor and keep us in the chair. Damn. What we’d really would be a way to hold us securely in the driver’s seat during trackdays.

Enter the harness bar. It allows us to use four-or-five-point harnesses in a street car. Fixes all the problems. We’re locked securely in the seat. We can left-foot brake, we can fingertip-control the car since we aren’t hanging on to the steering wheel in corners. It’s perfect.

Race cars don’t have harness bars. They have roll cages. When you roll the car and land on your roof, the main roll hoop and halo bar are supposed to prevent the roof from collapsing. Most of the time, this works. Sometimes the forces are too much to predict, but in general, when race cars roll over, the cage does what it’s supposed to do.

What happens in a street car? Well, the roof collapses. There’s some roll reinforcement in most factory cars, but it’s not what you get in a race car. When the roof collapses, it’s okay, because a three-point belt allows your head and torso to move forward, away from the collapsing roof.

Unless, that is, your head and shoulders are locked in position by shoulder harnesses. What happens then? Simple. Your neck supports the force of a rolling automobile landing on the roof. Hope you have a strong neck. If you don’t, you are either dead or paralyzed.

Some track rats figure this out, so they go ahead and cage their street cars. That leads us to another problem. During a high-speed impact, your body and head will end up in all sorts of places, even if you’re strapped into the seat. I was in a race-car accident where the top of my helmet grazed the “halo bar” at the juncture of roof and windshield. Without that helmet, I’d have cracked my skull. It’s illegal to wear a helmet on the street in many states. Don’t ask me how I found that out. Even if you don’t crack your head, your hands, arms, and other soft body parts may come into direct contact with solid steel rollcage bars. That’s a contest the steel bar always wins.

There’s a race-car safety system, and it consists of a full cage, five-point harnesses, helmet, and full race suit. There’s a street-car safety system, and it consists of three-point inertia belts, airbags, and soft interior surfaces. Don’t mix the two. The results are never good. It’s mandatory to wear a helmet at most trackdays, unless you’re driving the ‘Ring, so that’s just something we have to live with. The rest of the time, however, be smart. Leave the racing equipment at the track. If you think your car is too fast to drive on-track without a half-cage or five-point belts, it’s worth considering whether you and your massive talent really shouldn’t be in a real race car.

Our Mystery Car, for example, can be raced at any Flat Rock ARCA race for the staggering sum of $300 plus damage. That includes entry to the race. Why not give it a shot and see whether you’re ready to be a racing superstar? I wasn’t quite ready myself: as the official ARCA report shows, I finished one step off the podium in my oval-track debut. This was my ride: behold the amazing Flat Rock Tempo!

Get the latest TTAC e-Newsletter!

38 Comments on “Five-Point Belts Will Paralyze You and Other Fun Safety Facts...”


  • avatar
    bumpy ii

    “Where on your arm does the wheel make contact? For most street drivers, the answer will be “the ends of my fingers, maybe.””

    Huh. I didn’t think it was possible to put the seat back that far. That’s what I get for spending my life in subcompacts, I suppose.

    “not all inertia-reel seatbelts will hold us in the seat when it happens.”

    CG Lock? I didn’t like the thing at all, but some folks do.

    The gist of the article is valid, but overlooks the fact that most people turn their street car into a tweener-mobile because they can’t afford a full-time dedicated race car (and the trailer and tow vehicle for it).

    Is the chiropractor in the last pic any good?

  • avatar
    pariah

    Aahhh, a Tempo; I had it pegged as a first-gen Escort.

  • avatar
    Robert.Walter

    The polycast wheel and cowl trim in the first pic gave it away… the door handle, key trim, and the gap filler betw the roof and rr 1/4 panel confirmed it.

    Good article BTW.

  • avatar
    Ion

    At my job, I really am amazed at the variety of seating positions people have. I prefer to sit back in my seat with the seat at a 90 degree angle, close enoungh to have my entire toes on the gas pedal at WOT. But I’ve seen people sit huddled at the edge of their seats or have had cars were the seats were reclined at very low angles. I can see how this people drive this way but It can’t be comfortable or safe.

  • avatar
    CarPerson

    Some NASCAR drivers drive with their chest just a few inches away from the steering wheel hub.

    My preferred position (5’10″) and my wife (5’7″) is the “Italian” driving position: Seat as far back as it will go with arms straight out. Incidentally, I’ve read this is best as it keeps you out of the crumple zone and out of the most aggressive part of air bag deployment.

  • avatar
    Demetri

    “Move your seat and seatback forward until it’s your wrist that touches the top of the steering wheel with your arm straight out.”

    Unfortunately, in many cars, the enclosure around the steering column is pretty bulky, and my knees start coming into contact with it if I get that close. I usually keep it so that the top of the wheel is at the bottom half of my palms.

  • avatar
    niky

    It’s best for ensuring that your hands will come off the wheel at the exact moment you need to be steering away from the accident.

    My friends and family used to chide me all the time for sitting too close to the wheel… and yet I sit the proper distance away for car control.

    Interesting article… I was thinking there would be some profound biomechanical reason for paralysis… not the fact that the harness would hold you in place to become the new B-pillar once the roof crushes.

    Five-point harnesses itch

  • avatar

    Schroth makes DOT legal harnesses in 4 and possibly 5-point:

    http://www.schrothracing.com/

    but, otherwise I agree completely with your statements.

    • 0 avatar
      Jack Baruth

      They may be DOT-legal, but if the car rolls, it won’t matter. :)

      Also, some people mount their DOT-legal harnesses to the rear seatbelt attachment points. This can lead to compression of the spine, which is a bad thing.

      • 0 avatar
        John_234

        I apologize for the necropost.

        Essentially, I’m wondering if a more rigid seat that was resistant to the crushing weight of a rollover, analogous to passenger rollover protection in a convertible, might change the situation of using a racing harness as a DD?

  • avatar

    Jack, how about an article about Auto-X? Are those people wasting their time, or do they provide the necessary base for the racing pyramid?

    • 0 avatar
      Jack Baruth

      I’m no autocrosser (I finished almost exactly halfway down the field in the SCCA 2007 National Championship) but I’ll write it, no problem.

    • 0 avatar
      ckb

      In my limited experience i’d call Auto-X a gateway drug. Its a really fun afternoon and you can start to explore the limits of traction (largely understeer when you inevitably overcook it in all those hair pins). Events are usually right outside your door +/- a 1/2 hour drive. As for your car you don’t need to worry about excessive brake or tire wear, just make sure its in a decent state of tune and you’re good to go.

      If its your bag you can really get in to it and start trailering your crx to national competitions and what not. Or somewhere along the way you’ll do a track day and never look back (the track being a speedball to auto-x’s pot brownies).

      As for being the base of the racing pyramid…if you’re driving around in your own car thinking of auto-x as your gateway to racing, you’re at least 15 years too late. You needed to start seriously karting when you were 5 to have a reasonable shot at a racing career (or so I’ve been told).

  • avatar
    supremebrougham

    I had heard about the whole stretching your arms out and letting your wrists touch the top of the steering wheel, it’s my preferred position, even though my knee ends up bumping the dash (I’m only 5’5″ and a half). I also heard that this is the way of determining if you are far enough from the airbag to be safe too.

  • avatar
    Robert.Walter

    For most of us, on public roads, competition driving stance is not relevant. What is relevant is keeping our head out of the DSAB deployment zone, and our knees off of the column shroud and dash knee bolster.

    This is accomplished by sitting as far back as possible, but yet still being able to fully depress the pedals with the ball of your foot, and being able to hold the wheel with a comfortably bent arm.

    And a safety belt that has no slack across the pelvis or torso (also goes even if your car has pyrotechnic (or if an old old Audi, then Procon-Ten) active belt pre-tensioners…)

  • avatar
    Morea

    “It’s illegal to wear a helmet on the street in many states. Don’t ask me how I found that out.”

    OK, I asking anyway. Anyone have any details on this? It is something I have always wondered about. Wouldn’t I be safer if I wore my helmet on the street and not just on the track? Aside from looking like an eccentric, what’s the problem?

    • 0 avatar
      geggamoya

      Depending on the helmet, it could restrict visibility to the sides and affect your ability to hear the traffic around you.

    • 0 avatar
      Morea

      Hearing yes, visibility no. Full-face helmets these days have eye openings with widths that exceed what anyone can see peripherally. Of course, open face helmets do not have this problem.

      As for hearing– how is it any worse than loud stereo systems. (Do any states set volume limits on stereos for INSIDE the vehicle?)

  • avatar
    geggamoya

    I don’t think those two examples are anything to be concerned about either, just the two i could think of that might affect driving.

    Funny helmet in car story:
    An acquaintance of mine used to complain to his wife about her poor driving, and was told by her to never critisize her driving or get out of her car. The next time he did shut up, with a helmet on his head. The wife was not satisfied with his solution.. :D

  • avatar
    twonius

    How do cars like the GT3 and R26R deal with this problem? It looks like they keep the cage well behind the driver, but there’s probably a lot more to it.

  • avatar

    Yes, that’s an Omega Speedmaster “Broad Arrow” I’m wearing.

    And you’ve just made it tax deductible by writing about it.

  • avatar
    OMG_Shoes

    Interesting. Makes me think of these 4-point passenger car belts. I note the vendor proudly states “These four point belts are Federal Safety Standard approved #302!”. Fine and great, but standard #302 covers flammability of interior materials, not seat belt design, construction, or performance. H’mmm.

  • avatar
    RavenOne

    Harnesses must be mounted perpendicular to the driver’s back. Too high, and the driver can slide up when upside down, too low and it will compress the spine.

    Just because it holds you snugly doesn’t mean it’d done properly…

  • avatar
    hurls

    Not a racer here, nor do I play one on weekends. But I do own a Miata, and you don’t have to look very far to find plenty of pictures of Miatas upside down next to mountain/canyon roads.

    A lot of people DD Miatas with rollbars ( bars, not cages), but I often wonder as someone on the tall side for this car, if I’d not be trading the potential crushed head in the dirt/pavement head for a potential smashed like a watermelon at a Gallagher show head on the roll bar were I to install one.

  • avatar
    esldude

    Alternate method of spacing which gives roughly the same result is as follows: Put your right arm out straight grasping the wheel at 9 o’clock or left art at 3 o’clock. If you can grasp the wheel on the opposite side with your arm pretty nearly straight, you are well positioned for good control of the wheel.

  • avatar
    PeriSoft

    Don’t run a car on-track that hasn’t got a full cage, a good racing seat, and a full harness. Full stop.

    If you can’t afford two different cars, don’t do track days. Get a Formula Vee, or buy a total beater to do track days, but don’t run fast in a car without a real cage. Street cars are really good at protecting you from a street accident; they haven’t been designed to handle off-angle impacts with armco at 100+mph. You will die.

    Either go fast in a car built to handle it, or don’t go fast at all.

    My dad raced in the SCCA, FIA, and IMSA for many years, in everything from Vee to GT1. He hasn’t run a real race car for quite a few years, but did a track day in his 350Z for grins. He was looking at setting up a C6 to do street/trackdaying, but came to the conclusion that it was foolhardy. The same car cannot do both things well enough to be worth the risk. He’s going to gut the C6, put a real cage in it, and do it right.

  • avatar
    ZoomZoom

    Regarding the “Leppen Chiropractic” advert on the back wall in the last photo of the series:

    Is it irony or just creative target demographic work?

  • avatar
    porschespeed

    Not street legal?

    Depends on where you are.

    In most states, if it has headlights, run/turn/brake lights, a horn and a few other amenities, it’s able to be plated.

    May have to do it as a “kit-car”, but under the majority of states’ regs, you can license an old CART car with a few concessions to the DMV/DOR.

  • avatar
    George B

    Jack, A friend of mine was talking to me on the phone as she drove around Columbus Sunday evening. She suddenly said she saw “the most beautiful lime green Audi” and somehow I was able to describe the driver. Small world!

  • avatar
    shivak

    “During a high-speed impact, your body and head will end up in all sorts of places, even if you’re strapped into the seat.”

    This is very, very bad. Don’t forget your HANS device!

  • avatar
    Tosh

    “…. This is more sideways force than I would encounter if the driver’s seat were mounted sideways on a wall and I was trying to sit in it. No wonder, then, that during fast driving we find ourselves sliding around in the seat a lot.”

    Yes, except you are ignoring the friction due to the downward force from the 1g (your weight due to gravity) which acts against you sliding around as much as you would if you were sitting in a seat mounted sideways.

  • avatar
    RRocket

    TTAC is always pretty quick to point out flimsy studies, or “studies” not backed up by research. So I’ll put it to you. Where is the research to support this article? How many people in the USA have actually died using 4/5 point belts with a harness bar on the street?

    Sheesh…you guys are starting to sound like MSM with fear mongering articles like this.

    • 0 avatar
      bradley76

      Exactly, the comments and writing are so misleading, one could get a more solid response from a politician about ethics. Multi point harnesses on a sub developed chassis, questionable. However, to say they’re all bad/dangerous isn’t the truth about cars, it is a series of omissions that fails to both correct public perception of safety devices and advance their knowledge of such technology. Nobody bats an eye at the roll cafes in Ruf cars as a factory manufacturer, yet they are criticized in your article with the halo bar comment and to not mix the two with street driving, multi point harnesses or roll cages. How does Ruf do it,btw?

  • avatar
    AKADriver

    There have been a number of vehicles which used the aforementioned Schroth or Sabelt 4-point harness as original equipment in European markets. They’re all limited-production performance cars, however; there aren’t enough of them to generate crash statistics.

    A roof-crushing rollover in a street car is never a good experience. Partial ejection is a common result with a 3-point belt, and that’s not any better than the hypothetical harnessed scenario. Thankfully, street rollovers in passenger cars are rare.

    Building a “tweener” car is futile, but you can take measured risks. I run a roll bar in my Miata that sits entirely behind the passenger compartment. Before doing any serious track work with it, I plan to add properly-installed seats and harnesses – and then take them back out for street driving.

  • avatar
    63chevies

    My daughter has a 78 jeep cj5 and with the risk of roll over I built a full rollcage and 4 point harnesses for driver and passenger with a passenger safety handle to grab so your arms stay inside the vehicle. I realize the article is not about a jeep but you can’t lump all street driven vehicles into one group. I also added wider axles and a built 302 Chevy small block with 1000 cfm MPI fuel injection so the gas pedal can get it out of as much trouble as the brake pedal.


Back to TopLeave a Reply

You must be logged in to post a comment.

Subscribe without commenting

Recent Comments

New Car Research

Get a Free Dealer Quote

Staff

  • Authors

  • Brendan McAleer, Canada
  • Marcelo De Vasconcellos, Brazil
  • Matthias Gasnier, Australia
  • W. Christian 'Mental' Ward, Abu Dhabi
  • Mark Stevenson, Canada
  • Faisal Ali Khan, India