Myth about race seats and harness being dangerous without a rollbar / cage

[CMM3]

This should help put to bed the myth that a race seat and harness without a cage is more dangerous. A discussion resulted within a thread I started regarding the danger in using a Sparco Harness Bar in a z3 Coupe a short while ago in the Z3 section.

For anyone who is looking at adding safety equipment to their car you can add a race seat and harness and improve the safety of your car.
A cage can always be added later if desired.

It is critical to have the seats and harness properly mounted and positioned.

The information below is from the owner of HMS the company who specializes in safety equipment for track and race cars.


Injuries in rollovers generally result from the head or other body parts being partially ejected (or exposed) to the side window, head contact with the door frame (with a 3-point belt you are directed that direction), or in the body "dropping" onto the roof when the car comes to rest upside down.

During a rollover it is not unusual to see g-loads of 10 to 35. It is quite impossible to control any actions of the body by human force at much more than 5g if even that. You have absolutly NO POSSIBILIY OF CHOOSING THE DIRECTION OF YOUR BODY (ducking out of the way) You are basically along for the ride. Severe head and neck injuries usually occur NOT by the roof collapsing but by the body dropping down on the roof. During the event, the body is basically suspended in space (even in a harness), you have no opportunity or possibility to duck or move out of the way of a collapsing roof. At the end of the event (if the car is inverted) the risk is that the body drops down and the head hits the roof causing the head or neck injury.

A properly installed and worn 4, 5 or 6 point belt will help to keep the body properly positioned in the seat which is the best source of protection. A very tight lap belt might even get you an inch lower (further away from the roof). Most newer (1990+) cars have signifiant roof structures that even when collapsed provide more protection than you might imagine. Ask any EMT and they will tell you that they seldom see serious head or neck injuries resulting from a crushed roof.

John Melvin (nationaly recognized independent racing safety expert) touched on this topic at the recent SCCA National Convention with basically the information above. As long as a 4, 5 , or 6 point belt is installed in COMPLETE complience with the manufacturers instructions you will be better off with such a harness in a rollover with or without a rollbar.
_________________
Joe Marko

[timsev]

That's some good info but me thinks the wolves are going to start attacking soon.

[LukeP]

The reason is more-so to have proper angle of the shoulder belts vs mounting a harness to the floor. The shoulder belt angle is important for a front impact.

Harness bars do the trick, but cost the same as a roll bar, so why not have the added protection?

[SSRI]

Thanks for this post, been on the edge about getting fixed back seats in my car with out a cage this summer, but now I am, will run a 4-point and a harness GUIDE bar.

The reason is more-so to have proper angle of the shoulder belts vs mounting a harness to the floor. The shoulder belt angle is important for a front impact.

Harness bars do the trick, but cost the same as a roll bar, so why not have the added protection?

Harness guide bar, 120 bucks, or if you have a car with rear head rests use those, from my understanding the rear headrests are within level of your shoulders and are not going anywhere during a crash.

Of course this is coming from a HPDE view, not true racing.

[MasterKwan]

He's just asking for a law suit.

http://jalopnik.com/5390934/mustang-...over-tire-wall

Mustang had a rollbar too. You can see the feet sticking through the floor sheetmetal.

Without some real test results, I'm not sure how his opinion is any more valid than any other forum poster.

[Jimax]

Still boggles my mind why people will throw thousands of dollars on suspensions and lightweight wheels but skimp on safety. Would you put on a ballar suspension up front but leave the rear stock? Of course not because that's preposterous. If you're going for safety, less is not more.

[CMM3]

I posted another thread in the z3 section warning that the Sparco Harness bar made for a Z3 coupe is a death trap.
Be sure that what you use for a harness bar is at the proper angle in relation to were the shoulder straps exit the seat and it can withstand the forces in put on it in an impact.
If you check out Brey Krause you'll see they test there harness bars to meet DOT requirements http://www.bkauto.com/

[SSRI]

He's just asking for a law suit.

http://jalopnik.com/5390934/mustang-...over-tire-wall

Mustang had a rollbar too. You can see the feet sticking through the floor sheetmetal.

Without some real test results, I'm not sure how his opinion is any more valid than any other forum poster.

So essentially the roll bar became useless in this situation? The whole point is to avoid the roof from crushing, but since the bar went through it did nothing to stop the roof from caving in.

How different would it have been if the mustang wasn't running the roll bar?

[breakfast]

and how does the race seat compare to an oem seat?(which a lot of people toss in harnesses with)

[SSRI]

and how does the race seat compare to an oem seat?(which a lot of people toss in harnesses with)

It shouldn't be much different besides an adjustable angle, a member on here who works for Recaro, said reclining seats are NOT designed to break in a crash if the roof caves in. So in design theory the only difference is materials, and back angle...

[LukeP]

And harness guides. OEM seats do not have a provision to locate the belts, which should not be overlooked.

[MasterKwan]

So essentially the roll bar became useless in this situation? The whole point is to avoid the roof from crushing, but since the bar went through it did nothing to stop the roof from caving in.

How different would it have been if the mustang wasn't running the roll bar?

The takeaway is that a shitty rollbar is as bad as not having a rollbar at all.

My point though, is that the comment about strong roof structure in modern cars needs to be taken with a grain of salt. My Subaru had a very strong roof structure, my E36, not so much. Blanket advice like "modern roofs are strong" is just asking for an exception that injures people in the car.

[284Shooter]

And harness guides. OEM seats do not have a provision to locate the belts, which should not be overlooked.

I firmly believe that bringing a harness under the headrest pushed by L5/S1 to rupture. The straps rode on top of my shoulder instead of the seat and compressed my back when sufficiently tight. In fairness I had a preexisting condition but this took me from minor pain in the morning to crawling the next day.

[SSRI]

The takeaway is that a shitty rollbar is as bad as not having a rollbar at all.

My point though, is that the comment about strong roof structure in modern cars needs to be taken with a grain of salt. My Subaru had a very strong roof structure, my E36, not so much. Blanket advice like "modern roofs are strong" is just asking for an exception that injures people in the car.

If the mustang had fixed back seats where did the driver / passenger go? the seats must have been crushed no?

Also was it the roll bar or simply the sheet metal in the car? Every time I see my brothers roll bar I can only think, what is stopping from that floor board sheet metal tearing and making the bar useless, so is it the bar or just the design of the half cage?

[MasterKwan]

Also was it the roll bar or simply the sheet metal in the car? Every time I see my brothers roll bar I can only think, what is stopping from that floor board sheet metal tearing and making the bar useless, so is it the bar or just the design of the half cage?

To me, if you're bolting a rollbar to the sheet metal floor, it's basically a harness bar. The floor has no strength to speak of and tear through probably doesn't take much. Essentially you're depending on the roof to protect the rollbar from full impact. I had a bolt in in my subaru and that's what I thought of it as, a place to bolt my harness too.

As for where the mustang people went, I don't know. they walked away apparently. The mustang accident is really worst case where the whole weight of the car came down on the roof. I saw a 350Z roll at summit and the roof collapsed on the instructor side but, the driver side stayed up. They had to crawl out the driver's side window.

[CMM3]

The reason is more-so to have proper angle of the shoulder belts vs mounting a harness to the floor. The shoulder belt angle is important for a front impact.

Harness bars do the trick, but cost the same as a roll bar, so why not have the added protection?

It wasn't so much a cost issue for me. I was thinking about a cage but time constraints prevented going this route. But I needed to get a lower seating position, anyone over 6' tall in a Z3 Coupe with a helmet on can attest it's a tight fit. So I had a need to install race seats which then left me with the decision between having a gage put in or to fabricate a harness bar. Timing didn't allow for the cage. But since I was having reinforcement work done which yielded a very strong reinforced cross bar tying the rear shock towers together it yeilded a platform to build a harness bar from. So I went this route. I may at some point in the future have a cage put in but for now doing HPDE's I think I've got an excellent solution

[Itsablurr]

The primary issue with using a roll bar/fixed backs/harnesses on the street is the lack of upper body mobility that is required for safe street driving. Relying on mirrors-only for the task of checking for blind spot idiots, any number of weird merge angles into traffic, etc etc is a recipe for a higher likelihood of misjudgement resulting in some sort of collision.

[shiza40]

Vehicle roof structures, even "modern" ones, are only required by law to pass static loading tests that use only fractions of the vehicle's weight (about 500 pounds) and as a result will likely deform and crush during a rollover. This will suck for you on the street or on the track. I doubt there is any data that says you are more likely to roll over on the track, but since speeds are obviously higher, who knows. The main point to his whole debate, for me, is that if you are only willing to add in "some" of the safety equipment available to you then you also better be willing to deal with the consequences of the "rare" events you purposely chose to risk wouldn't happen to you.

Internet debate doesn't mean much when you are vegetable or worse.

[SSRI]

The primary issue with using a roll bar/fixed backs/harnesses on the street is the lack of upper body mobility that is required for safe street driving. Relying on mirrors-only for the task of checking for blind spot idiots, any number of weird merge angles into traffic, etc etc is a recipe for a higher likelihood of misjudgement resulting in some sort of collision.

You can still properly retain stock seats belts with a fixed back seat, you just need to properly position the female receptacle.

As long as the belt isn't touching the bolsters and is actually up against the person it should be fine, lots of people make the mistake of running them over the side bolster when they NEED to be run under through the belt loops.

Another "solution" would be to loosen the top of the harness an inch or so to give you some wiggle room, I'd still go with stock belts.

[TOOLEAN]

This expert is really going to advocate a 4-point harness?! This should be good...

[gforcealt]

To me, if you're bolting a rollbar to the sheet metal floor, it's basically a harness bar. The floor has no strength to speak of and tear through probably doesn't take much. Essentially you're depending on the roof to protect the rollbar from full impact.

I poked a screw driver through the floor of my car when prying the roll bar foot into position.

Really, though, a screw driver is nearly a point load and the feet of a bolt-in roll bar are big and flat. If the Fed rollover protection requires the roof to withstand a static load of 500lbs, you have that 500lbs plus however much it takes to push the roll bar feet through the floor. It would probably take much, much more than 500lbs to push the feet of a bolt-in roll bar through the floor, so . . . The racing rule makers wouldn't require roll bars and allow bolt-ins if they didn't provide more protection.

I plan to have the floor of my car reinforced and tied into the side sill for just that much more protection.

On the safety of a harness and fixed back seat without a roll bar, you have to appreciate that there are no absolutes. HMS didn't say always and anytime, a fixed back seat and harness without a roll bar is OK. I read the quote as HMS saying that in most roll over accidents, a fixed back seat and harness without a roll bar is OK.

[jeremy5000]

[SSRI]

I poked a screw driver through the floor of my car when prying the roll bar foot into position.

Really, though, a screw driver is nearly a point load and the feet of a bolt-in roll bar are big and flat. If the Fed rollover protection requires the roof to withstand a static load of 500lbs, you have that 500lbs plus however much it takes to push the roll bar feet through the floor. It would probably take much, much more than 500lbs to push the feet of a bolt-in roll bar through the floor, so . . . The racing rule makers wouldn't require roll bars and allow bolt-ins if they didn't provide more protection.

I plan to have the floor of my car reinforced and tied into the side sill for just that much more protection.

On the safety of a harness and fixed back seat without a roll bar, you have to appreciate that there are no absolutes. HMS didn't say always and anytime, a fixed back seat and harness without a roll bar is OK. I read the quote as HMS saying that in most roll over accidents, a fixed back seat and harness without a roll bar is OK.

Thank you, people are jumping to the point quickly, it was never said in the post that if you use these safety items you WILL survive a 150mph crash at the Glen.....

[elliott95]

Just skip a roll bar and pony up the money for a cage OR know what could possibly happen to you in the event of an accident. End of story.

The sad part is that passengers have no idea how safe/unsafe the car is.....

I almost bought a roll bar but after seeing cars flip at even 50mph into trees i spent the extra cash....

Personally i would not trust anything bolt-in without significant reinforcement plates but still i would be wary.

[LukeP]

I poked a screw driver through the floor of my car when prying the roll bar foot into position.

Really, though, a screw driver is nearly a point load and the feet of a bolt-in roll bar are big and flat. If the Fed rollover protection requires the roof to withstand a static load of 500lbs, you have that 500lbs plus however much it takes to push the roll bar feet through the floor. It would probably take much, much more than 500lbs to push the feet of a bolt-in roll bar through the floor, so . . . The racing rule makers wouldn't require roll bars and allow bolt-ins if they didn't provide more protection.

I plan to have the floor of my car reinforced and tied into the side sill for just that much more protection.

On the safety of a harness and fixed back seat without a roll bar, you have to appreciate that there are no absolutes. HMS didn't say always and anytime, a fixed back seat and harness without a roll bar is OK. I read the quote as HMS saying that in most roll over accidents, a fixed back seat and harness without a roll bar is OK.

Reinforcing on the sidesill is pretty much a requirement for proper bolt-in mounting. PITA for some? Sure, but it's the right way to do it.