Safety aspects of racing seats and racing harnesses in street cars

[Inaccurate]

I feel woefully unprotected when wearing oem restraints. I feel that a FIA-Homologated racing seat and FIA-Homologated 6-point racing harness (when properly installed and worn) offers superior protection in a street car than the oem restraint system (inclusive of the airbag system). Among many car enthusiast forums, there seems to be a common notion that racing harnesses are less safe than oem seatbelts for rollover protection. The argument is that a racing harness will prevent the driver from moving to the side to evade the collapsing roof. Whereas with the oem seatbelt, the driver is able to move away from the collapsing roof. On the surface, this argument seems plausible. However upon closer examination, this notion has no merit. Here are some links to such discussions - Click here for Example 1 Click here for Example 2 Click here for Example 3 Click here for Example 4 Now to clarify, I am *not* saying that a driver will not experience reduced headroom and not suffer head/neck injuries during a rollover *with either* the racing harness or oem seatbelts. Head and neck injuries are very common with rollovers. This is a fact of life (risk) that we accept when we travel in a normal passenger car (sans a roll bar). My point is that a FIA-Homologated racing harness (when properly mounted and worn) is not less safe than the oem seatbelts during a rollover. Based upon my research (see links below), it is my conclusion that the FIA-Homologated racing harness (when properly mounted and properly worn) is actually much safer than the oem restraint system (inclusive of the airbag system) during a rollover. But, what about the roof crushing inward ? This is a sad fact that we all live with every time we ride in an automobile. We just do not normally realize it, or think about this risk. Based on the SAE (Society of Automotive Engineers) studies linked below, a driver will not have the freewill to evade the collapsing roof during a rollover. In my words, this is just wishful thinking by the uninformed person. As often citied by the SAE technical papers collectively, the true issue is the structural strength of the roof to withstand the rollover forces. The roof and other vehicle structures must be strong enough to resist occupant compartment intrusion that can increase the risk of head and neck injury. Below is an illustration depicting where the occupants (driver and passenger) will mostly likely be positioned if/when the roof crushes. This illustration is from a SAE technical paper that I purchased entitled "A Computational Analysis of the Airborne Phase of Vehicle Rollover: Occupant Head Excursion and Head-Neck Posture" (SAE Technical Paper 2005-01-0943). A driver will not have the freewill to evade the collapsing roof during a rollover. "During the airborne phase of vehicle rollover, the vehicle is spinning/rolling approximately around the center of mass" (SAE Technical Paper 2005-01-0943, page 4). Because the occupant is located some distance from the axis of rotation, the occupant will experience great centrifugal force during the rollover event. "In addition to head excursion, this study examined the occupant position at specific roll rates to map probable occupant postures and orientations relative to the occupant compartment" (SAE Technical Paper 2005-01-0943, page 4). "This information [in this study] can be used to understand occupant positioning at vehicle-to-ground contacts, which inevitably follow the airborne phase" (SAE Technical Paper 2005-01-0943, page 16). Through my entire research of the effects of seats and seat belts in rollover protection, I *never* encountered the suggestion that the oem restraint system provided, intentionally or unintentionally, the ability for the occupant to move away from the collapsing roof. On the contrary, I was bombarded with the fact (according to Society of Automotive Engineers) that the ideal goal is to *not* allow the occupant to move during any type of collision (especially rollovers)! According to the SAE papers, the flail (violent thrashing from being thrown about) of the occupant is very severe during a rollover. In fact, based on the SAE papers collectively, this flail and possible ejection is the most common reason for injuries and death during rollovers. To reduce or prevent flail during rollovers, according to the SAE papers collectively, a seatbelt should hold the occupant firmly against the seat (with no permissible movement) to offer the best rollover protection. According to another SAE technical paper that I purchased entitled "Testing of Seats and Seat Belts for Rollover Protection Systems in Motor Vehicles" (SAE Technical Paper No. 982295), improvements in rollover protection "can be achieved by reducing the seat belt system effective slack" and designing seat belts which "restrict occupant movement" (page 7). This seems to me to be in favor of the racing harness. Whereas, the oem seat belt is problematic with maintaining tension during rollovers according to many of the SAE technical papers. This possible failure of the oem seat belt to maintain tension during rollovers could permit the occupant to consequently experience excursion leading to flail and possible ejection. Here is a case in point from my morning commute just a few weeks ago. Before leaving the house, I heard on the local news that there was a rollover investigation ongoing along my route. The news said it was a fatality rollover. Later as I was driving to work, I did see the vehicle. The police investigation (road blocked off) was still ongoing and the scene was still as it occurred. It was a very disturbing sight to me because of my recent research into this topic. I unfortunately could envision (in my mind) the trauma that this driver incurred. The vehicle was an SUV. It landed upright, so it must had done at least one complete roll. There were personal items (papers, clothing, etc.) on the road surface all around the vehicle. These items were ejected from the vehicle during the rollover event. I had seen other rollovers in the past, and there is always personal items scattered along the road with each rollover that I had ever seen. I paid careful attention to the roof of the vehicle this morning. It was *not* crushed to any significant extent. But, the driver sadly died from the rollover. What happened ? Remember the personal items along the road ? To me, this indicates several things. The rollover is indeed a very violent event from the rollover action itself. Just like my research had revealed. If the flail is strong enough to eject small lightweight objects (papers, clothing, sunglasses, etc.) from the vehicle, imagine what is happening to a person during the flail. Furthermore, if these small objects were ejected, was the driver ejected ? There is a strong chance the driver was ejected either completely or partially enough to cause death. Modern seatbelts do *not* retain the occupant very well to prevent partial ejection during a rollover. "...Partial ejection remains a primary important injury mode with modern seat belt systems" (SAE Technical Paper No. 982295, page 7). If the occupant is not ejected, the violent flail in itself is sufficient to cause death. This is why I choose a racing harness, especially after witnessing this unnecessary death. My FIA-Homologated racing harness that was properly installed and worn *will* keep me firmly in my seat during a rollover. "Design attributes that may favorable affect the performance of seat belt restraint systems for rollover protection include seat attributes which lower the occupants body in the vehicle" (SAE Technical Paper No. 982295, page 7). The ability to be mounted low is a feature of the racing seat. Having a lower seating position provides more headroom if the roof did crush. This is an advantage that I gained with the racing seats. With my preferred mounting position for the racing seat, I now sit 2 inches lower than with the oem seat (which had been adjusted as low as the oem seat allowed). I looked forward to having a lower seating position. The oem seat did not lower enough for my taste (and, I am only 5'7"). In the same study (SAE Technical Paper No. 982295), another conclusions was a seat that restricted occupant movement was a favorable feature for rollover protection (page 7). This seems to be in favor of the FIA Homologated racing seat which has bolstering to firmly hold the occupant. To this extent, SAE Technical Paper No. 982295 asserts that as a seat provides more cushion (for comfort) that the seat becomes less safe. That is, the cushion prevents the occupant from being held firmly into the seat, and the occupant consequently experiences excursion leading to flail and possible ejection. This favors the FIA-Homologated seat, which does not have thick cushions and has side bolstering to firmly hold the occupant. Emphasis was placed on rollover collisions throughout this discussion because this seems to be the most controversial topic in regards to having a racing seat and/or racing harness in a street car. The other forms of collisions include frontal collisions, rear-end collisions, and side impacts. For these collisions, the FIA-Homologated seat, FIA-Homologated harness, and FIA-Homologated bracket are tested to withstand the most severe impacts. The FIA seat test requires a minimum performance of 20 g for rearward impacts and 15 g for side impacts (Source: "FIA Standard For Competition Seats", page 3). In my opinion, the racing seat provides equal or greater protection than the oem seats for frontal collisions, rear-end collisions, and side impacts. In conclusion, I feel that a FIA-Homologated racing seat and FIA-Homologated 6-point racing harness (when properly installed and worn) offers superior protection in a street car than the oem restraint system (inclusive of the airbag system). I even tried to encourage my wife to allow me to install a 2-inch harness in her car for her protection, but she did not want the inconvenience of strapping into a harness (however, she does wear oem seat belts). While researching the SAE technical papers, one fact was stated over and over again - the occupant *MUST NOT* be allowed to move during a collision, including a rollover collision. The occupant *MUST* be held in position as firmly as possible against a rigid seat (rigid meaning no cushioning) throughout the collision event. To me, this is the epitome of a FIA-Homologated racing seat and FIA-Homologated 6-point racing harness (when properly installed and worn). Below are links to several SAE Technical Papers. Each link will give a brief summary of the respective technical paper. And, I found the summaries (abstracts) to be very helpful in of themselves. By the way, these are easily purchased online for immediate downloading (pdf format) for $14 each. I purchased several...fun reading. To aid you with reading these summaries and/or papers, I have included a brief translation of some commonly used terms: Excursion - the displacement (or distance moved) of the occupant from the initial seating position. Flail - the violent thrashing (waving and swinging motion) from being thrown about. Hybrid III - a test mannequin (dummy). Kinematics - the detailed study of the motion of a body. Biomechanical Principles of Racecar Seat Design for Side Impact Protection(click here) Biomechanics of 4-Point Seat Belt Systems in Farside Impacts(click here) Investigations Made on Riding-Up of the Lap Belt of a Safety Harness System(click here) Restraint Systems in Racing Accidents(click here) Biomechanics of 4-Point Seat Belt Systems in Frontal Impacts(click here) The Relationship Between Vertical Velocity and Roof Crush in Rollover Crashes(click here) Ejection Mitigation in Rollover Events - Component Test Development(click here) Occupant Injury in Rollover Crashes: A Reexamination of Malibu II(click here) A Study of Kinematics of Occupants Restrained with Seat Belt Systems in Component Rollover Tests(click here) Injury Causation in Rollover Accidents and the Biofidelity of Hybrid Iii Data in Rollover Tests(click here) Injury Mechanisms and Field Accident Data Analysis in Rollover Accidents(click here) Rollover Ejection While Wearing Lap and Shoulder Harness: the Role of the Retractor(click here) Modelling the Effects of Seat Belts on Occupant Kinematics and Injury Risk in the Rollover of a Sports Utility Vehicle (SUV)(click here) Rollover Severity and Occupant Protection - A Review of NASS/CDS Data(click here) Modeling the Effects of Seat Belt Pretensioners on Occupant Kinematics During Rollover(click here) A Computational Analysis of the Airborne Phase of Vehicle Rollover: Occupant Head Excursion and Head-Neck Posture(click here) Factors Influencing the Likelihood of Fatality and Serious/Fatal Injury in Single-Vehicle Rollover Crashes(click here) Rollover: A methodology for restraint system development(click here) Near- and Far-Side Adult Front Passenger Kinematics in a Vehicle Rollover(click here) Three-Point Restraint System Design Considerations for Reducing Vertical Occupant Excursion in Rollover Environments(click here) Initial Occupant Kinematics in the High Velocity Vehicle Rollover(click here) The Contribution of Occupant and Vehicle Dynamics Simulation to Testing Occupant Safety in Passenger Cars During Rollover(click here) Testing of Seats and Seat Belts for Rollover Protection Systems in Motor Vehicles(click here) Head Excursion of Seat-Belted Cadaver, Volunteers and Hybrid Iii Atd in a Dynamic/Static Rollover Fixture(click here) Characterization of Belt Restraint Systems in Quasistatic Vehicle Rollover Tests(click here) Investigation of Restraint Function on Male and Female Occupants in Rollover Events(click here) Modeling of Occupant Impacts During Rollover Collisions(click here) Testing for Occupant Rollover Protection(click here) Human Subject Experiments in Occupant Response to Rollover With Reduced Headroom(click here) Evaluation of Experimental Restraints in Rollover Conditions(click here) Compressive Neck Preloading During the Airborne Phase of Vehicle Rollover(click here) Timing of Head-To-Vehicle Perimeter Contacts in Rollovers(click here) Headroom, Roof Crush, and Belted Excursion in Rollovers(click here) Electromyographic Activity and Posturing of the Human Neck During Rollover Tests (click here) Determination of the Significance of Roof Crush on Head and Neck Injury to Passenger Vehicle Occupants in Rollover Crashes(click here)

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[godfather2]

whoa, time to go for the ph.d

[fsttyms1]

Yea..... Try to get the majority of the population to wear a 4,5,even 6 point harness. Its hard enough for the govt to get people to wear the simple one we have. 4s have been talked about and i can see them mainstreamed. 5 or 6 no way. There just wouldnt be the ability to be any comfort for the occupants and less people would wear them.

Nice slow rollover

http://video.google.com/videoplay?do...arch&plindex=2

[TheMirror]

Oh my goodness, what exactly was Antonio thinking there??? He missed that braking point by a MILE. I guess there's a reason why he isn't racing in F1 anymore.

Sweet original post by Inaccurate. I'm gonna dig through it deep because this is a subject that really interests me.

Cheers,
-Mirror

[Whiskers]

But drinking and driving is cool, right?

[charliemike]

What do you suggest? A HANS system?

[BENDER08]

as long as you have a roll cage and your on the track

But drinking and driving is cool, right?

[Inaccurate]

By the way, this thread is a supplement to my TL Diet thread. If you wish to see pics of my racing seats, see the link below.

Putting the TL on a diet (click here)

[o1s]

i used to have a 5 point harness in my old s14. reaching for almost anything like radio, a/c, or adjusting a/c vents is almost impossible when strapped in.

[Will Y.]

Originally Posted by fsttyms1

Yea..... Try to get the majority of the population to wear a 4,5,even 6 point harness. Its hard enough for the govt to get people to wear the simple one we have.

Generally, a racing harness is safer than the shoulder/seat belt combo during a collision WHEN WORN.

This is the reason we have airbags and explosive charges all over the frikkin' interiors of cars nowadays-- many people were lazy and/or too moronic to realize that shoulder/seat belts will save their butts in a wreck, so they didn't use them and the safety lobby/gov't had to come up with "passive restraints" like airbags. n:

[Devastation]

damn man, you did your research

[derrick]

I was in a rollover accident (went around 1.5 times) when I was a kid. The forces are incredible ... it was like my life flashing before my eyes ... glass breaking everywhere, it was almost surreal.

However, I was in the backseat (passenger side) and I was kept snugly in the seat (wearing seatbelt). In fact, I had to take my seatbelt off to get out of the car. I broke my collarbone trying to land on my side (than my head).

I don't know if the multi-point restraint would have helped me further. I know a rollbar would have helped because the A-pillar on the front passenger section collapsed on the '89 Camry ... good thing that seat was empty or else ... massive head-injury!!! I'm sure a rollbar would have more evenly distributed the force on the roof section and less of a collapse on the A-pillar.

Good research you did. Now ... if they lower the center of gravity on the SUV ... would have that prevented the rollover? I think prevention is more important in research than reactive type safety systems ...

[Maximized]

I've been in many race seats w/ harnesses. The cars always had roll bars. A properly worn harness and seat will allow literally no movement. If the roof crushed without a roll bar, it is going to crush your skull. I've seen many roll over collisions and a tall driver simply would not fair well without a safety cage. An OEM 3 point harness allows you or the force to move your torso.

[Maximized]

Case in point:

This happened a few years ago at Gingerman. My friend was running his car while this happened.

[Inaccurate]

Originally Posted by blueracer17 (copied from the "TL Diet" thread)

I haven't read all the posts in this very long thread, but I have an observation regarding your shoulder harness install. The way they are installed now, with the mounting point so far below shoulder level, will break you back in a head on collision. The shoulder harness mounting point should be level or within about 3 inches of shoulder height. They should also not touch the seat, they should be centered and then go over your shoulders. I am not an engineer, but I built a super late model asphalt circle track race car and safety came first since concrete always wins at 130 MPH. The seat was a custom built Butler Built just like the one 50% of the nascar guys use. The belts were 6 point Simpson Platinums mounted per the manufacturer, I also used a HANS device. I have seen so many bad installs. Its hard to properly install a race harness in a street car without a rollcage. What you need is a 6 point roll cage with a horizontal bar that passes behind the seat slightly below shoulder level. Then you run the shoulder harness over this bar and bolt it to the floor in a straight line pull arrangement. You have them mouned way low and they are crossed, not sure why you would cross them. I'm sure you did your research, but I did mine and this is what I came up with. Your current setup will compress your spine as it sinks you into the seat bottom. Also, you don't want the shoulder harness to run up hill once it leaves your shoulders, 10 degrees down max, closer to level the better and don't let it touch the openings in the seat. I just realized too, that your harness is very long, shorter is better here. There are 100 different things to consider, I have only mentioned a few. There is also a science to the lap and 6 point harness. The key is to have the belts catch you early in the "event" ie crash to help control the body movements. Long runs and poor geometry dont allow this to happen. Sorry it got a little winded. I just hate to see people make mistakes when they have the best of intentions, esp. regarding safety matters.

First and foremost, thanks for the civil exchange of thoughts. I appreciate your polite presentation. Thanks for taking the time to reply.

Driving an automobile is always risky. The only truly safe seat is in a person's living room (in front of the television). I am aware of every issue that you mentioned. And, you are correct. You citied the IDEAL installation. I am fully aware that my install consist of compromises. However, please keep in mind that even the oem system has many compromises too as I have presented in this thread.

And, you are correct that I spent many hours [days and nights] doing my research regarding how racing seats and racing harnesses should be installed. I am fully comfortable with my install... More so than I was with the oem install. Not saying that I am right. Just saying that I am aware of the compromises and I feel more safe with my system than I felt with the oem restraint system. As they say, this solution fits *me*.

Below, I will share my reasoning regarding the respective issues that you correctly pointed out.

Racecars experience much more g-force in collisions because they have rigid tubular framing. Whereas street cars have designed crumple-zones. Also, racecars reach higher speeds too which greatly increases the g-force in a collision. Street cars are expected to sustain approx 20 g's in the most severe collisions. On the other hand, racecars are expected to sustain much higher forces (perhaps 30 to 40 g's).

<< The way they are installed now, with the mounting point so far below shoulder level, will break you back in a head on collision. >>

A racing harness should be mounted near horizontal. This is paramount when a HANS is used. However for non-HANS use, some harness makers consider my setup as "acceptable" (no more than 45 degrees).

EXAMPLE 1


EXAMPLE 2


I have reviewed slow-motion video and high speed photographs of a human tester strapped into a test-sled wearing a racing harness.

EXAMPLE 3


As I see it, the upper body curls forward suggesting that my shoulders will be level with the access holes in the seat in which the belt is routed. The big assumption here is that the seat will support the downward force that is being applied by the belts. And, I trust the FIA-Homologated racing seat to withstand that force (although it is not stated anywhere by the maker nor FIA).

<< they are crossed, not sure why you would cross them. >>

Please see my notes in blue color in the pics below.

EXAMPLE 4


EXAMPLE 5


EXAMPLE 6




<< Also, you don't want the shoulder harness to run up hill once it leaves your shoulders, 10 degrees down max, closer to level the better and don't let it touch the openings in the seat. >>

Just pointing out to other readers that my setup does not do this. I think this is being mentioned as general discussion (not related to my install).


<< I just realized too, that your harness is very long, shorter is better here. >>

No argument here. Yes, it is a compromise. The belt will stretch approx 12 inches or more in a severe frontal collision. I strapped myself in the harness, and plotted my positioning after experiencing the expected belt stretching. My head will barely impact the center of the cover for the steering wheel. However, there is another six inches of space under that cover before my head contacts anything solid. That is, even with the excessive belt stretch, I am comfortable that I will clear any hard objects during a frontal impact.

In closing, I wish to say "Thanks" for taking the time to point out possible problems with my install. I know that you meant to help, and I do appreciate it.

[charliemike]

Originally Posted by Will Y.

This is the reason we have airbags and explosive charges all over the frikkin' interiors of cars nowadays-- many people were lazy and/or too moronic to realize that shoulder/seat belts will save their butts in a wreck, so they didn't use them and the safety lobby/gov't had to come up with "passive restraints" like airbags. n:

Umm, no. I mean, that's not even close to the truth.

Side airbags have been shown to dramatically decrease injuries and fatalities when worn in conjunction with seatbelts.

All you have to do is look at the differences in IIHS tests between a car w/o side airbags and curtains and the same model with them ... And those crash test dummies are belted in ...

[phil2]

I have harnesses in my sti that I use at watkins glen all of the time, but I got it connected to harness bar and I have hans.

[Will Y.]

Originally Posted by charliemike

Umm, no. I mean, that's not even close to the truth.

Side airbags have been shown to dramatically decrease injuries and fatalities when worn in conjunction with seatbelts.

All you have to do is look at the differences in IIHS tests between a car w/o side airbags and curtains and the same model with them ... And those crash test dummies are belted in ...

I hope I was somewhat close to the truth in that passengers' failures to use seatbelts was a primary motivating factor for passive restraints- which included either the motorized auto shoulder belts or the FRONT airbags in the late '80s-early '90s. Please enlighten us if there were other primary factors for the decision to require airbags.

The original primary factors for SIDE airbags or curtains, I don't know, but I'd trust a roll hoop and racing harness more than regular belts and airbags.

[blueracer17]

I understand that you feel that you are safe and have confidence in your installation. That said your sled test photos are from a reclined seat race car such as an Indy car or Formula 1 car. I have reviewed similar sled tests from full bodied race cars. These would more closely represent your situation. Most full bodied race cars run a seat with approximately 25 degrees of lay back. I still say that your install has the potential to compress your spine in a head on or try to push you under the lap belt. What happens in an upright seating position is the body actually trys to submarine under the lap belt. The 6 and 7 point harness help to reduce this by "capturing" the body sooner in the crash event. The sooner the belts "capture" the body, the less chance you have of accelerating before the belts finally "capture" you. This is due to the 6 and 7 point harness being mointed wide and close to the hips. I agree that what you have is better than the 3 point OEM system, but since you have decided to design your own system, I'm just pointing out the flaws.

Since I got flamed for not using pargraphs, here's a new one. I now see why you crossed the harness (the long run from the seat to the mounting point). I assume that is to keep the belts from sliding off the HANS device, or your shoulders I suppose. I'm not trying to belittle what you have done, it's very impressive, I just think that you are crossing a few different theories into one and they don't always mix (IE reclined seat and 25 deg. layback). I would focus my research on more upright seats. One last thing to consider, a car without a roll cage and multi point harness, will most likely kill you since you can't move to avoid a collapsed roof. I mean no disrespect and appreciate your open mindedness. Too often people think that there ideas are the best and don't want to hear what others have done and/or researched. In my case I have researched and then carried that research out to the real world (my race car). Good luck! How did you mount the ant submarine belt/s (cant remember if you used a 6 point or 5 point setup).

[CLpower]

What are you going to do with the air bags? Remove them right?

[charliemike]

Originally Posted by Will Y.

I hope I was somewhat close to the truth in that passengers' failures to use seatbelts was a primary motivating factor for passive restraints- which included either the motorized auto shoulder belts or the FRONT airbags in the late '80s-early '90s. Please enlighten us if there were other primary factors for the decision to require airbags.

The original primary factors for SIDE airbags or curtains, I don't know, but I'd trust a roll hoop and racing harness more than regular belts and airbags.

That's not what you said though

And to my knowledge airbags have never been proven to do anything for non-seatbelt-wearing fuckwits but fuck them up even further

Are we having this discussion? Really?

Roll hoops and racing harnesses? I'm sure that will sell well in Honda's next Odyssey.

[Inaccurate]

To enter into this other conversation....

Air bags were introduced into American autos in an attempt to protect those that refused to wear seat belts. And as mentioned, the air bags fall very short in their goal in gracefully protecting the "unbelted".

However as time progressed, air bags did begin to effectively supplement some shortcomings of seat belts. One example is the side-curtain airbag. This topic is covered in my opening post of this thread. One major flaw with modern seat belts is that the retractor fails to maintain tension during rollovers. The occupant is allowed to experience fatal flail or fatal ejection during a rollover because the seat belt retractor will release it's tension (allowing the belt to freely reel out along with the occupant). The solution (umm, band-aid) was to use side curtain air bags to hopefully prevent the occupant from being ejected out of the side window and to somewhat cushion the occupant during the flail.

[Inaccurate]

blueracer17,

I did *not* mean to imply that this single sled test photo of a reclined seat was the only thing that I reviewed. I really get the feeling that you underestimate me. Plus, I was hoping that you realized that I was intelligent enough to realize that the seat was reclined, and that I should take that into consideration (and, I did).

When you stated "will most likely kill you since you can't move to avoid a collapsed roof", this really disappointed me too. This is the whole point of my research, which was presented in the opening post of this thread. Therefore, it appears that you either did not read the material or you disagree with the SAE studies.

[Will Y.]

Originally Posted by charliemike

That's not what you said though

And to my knowledge airbags have never been proven to do anything for non-seatbelt-wearing fuckwits but fuck them up even further

Are we having this discussion? Really?

Roll hoops and racing harnesses? I'm sure that will sell well in Honda's next Odyssey.

My original comment was a follow up on fsttyms1's observations in post #3 regarding trying to get people to wear racing harnesses, let alone seat belts, in street cars. I was pointing out that people's reluctance to use shoulder/lap belts led to passive restraints, which led to all the airbags in personal passenger vehicles.
Roll hoops, safety cages and 4- or 5-point harnesses would be inconvenient to most for passenger cars (per discussion in this thread) but they might be safer than the shoulder harness/airbag set-up. However, that option is unavailable for social and regulatory reasons.

[EuRTSX]

70% of americans don't fit in racing seats and harnesses

[Maximized]

Originally Posted by Inaccurate

When you stated "will most likely kill you since you can't move to avoid a collapsed roof", this really disappointed me too.

See the picture of the E36 M3 above. If the car was equipped with a fixed back race seat and harness, the driver would likely have suffered severe injury. Instead, he walked away. Like I said, I've seen a few rollovers on the street and track and I personally wouldn't feel safe running a harness without a roll bar. It's cheap insurance if you plan to get into motorsports.

[blueracer17]

I'm checking out of this one. Good luck with your project. My comments were based on the information you presented to me in your original reply (test sled photos warnings ect). The fact remains that your harness is mounted to low and it rides on the openings in your seat. This is not correct and I stand by these statements. I did not read every single word of all your research, I have done enough of my own to feel I don't need to. I will take back the roll over statement, and leave it at that since my race car is a full tubular car with roll cage so roll over protection is abundant. As long as you are satisfied with your install and feel safe, who cares what I or anybody else thinks. Fact is, I would not do it totally your way.

[Inaccurate]

Originally Posted by Maximized

See the picture of the E36 M3 above. If the car was equipped with a fixed back race seat and harness, the driver would likely have suffered severe injury. Instead, he walked away. Like I said, I've seen a few rollovers on the street and track and I personally wouldn't feel safe running a harness without a roll bar. It's cheap insurance if you plan to get into motorsports.

I don't doubt that some rollover victims where able to escape injury from a collapsing roof because they were able to move around. However, I will say that it was luck or god's will.

Many years ago, folks were less serious about their auto safety. Back then, a common mentality among some people was that they would not wear seat belts so that they could be thrown-free from the vehicle as opposed to being trapped in the vehicle during a hellacious rollover. Little did people think that the vehicle would roll over on them if they were ejected.

Believe it or not, there are cases of unbelted people getting thrown free of their vehicle and escaping with minimal injury (scratches and minor bruising) during a roll over or other collisions. This was pure luck or god's plan for them to survive. However, it is not recommend that one rely on this type of luck (not wearing belts in order to be thrown free) to survive a crash.

I admit that my example above is extreme. I agree that there is a greater chance (than in my example above) that a person might benefit from flail (being thrown out of their seat and seat belts) during a roll over if the roof collapsed. On the other hand, you need to admit that many people die from flail and/or ejection (partial or complete) during roll overs because their seat belts did fail them.

"Seat belt use is the most effective way to reduce the risk of injury or death in a rollover. More than 70 percent of people killed in rollover crashes are unbelted. Without seat belts, occupants in vehicles that roll can be thrown from the vehicle, greatly increasing the risk of serious injury or death" Source: Insurance Institute for Highway Safety - "What can be done to reduce the likelihood and severity of injuries when rollovers occur?" (click here). Again, another credible source (other than the credible SAE citied in my opening post) stating that occupants having the freedom to move around is *not* a good thing. Did these unbelted occupants survive the collapsing roof because they moved away from the collapsing roof ? According to this credible source, the answer is "no". "More than 70 percent of people killed in rollover crashes are unbelted."

"But the assumption that a weak roof collapsed and crushed the passengers is simply not supported by the data. In 74% of cases, roof intrusion was not a factor. Rollover accidents are fatal because the occupants are usually ejected, or partially ejected, during the crash" Source: "The Counterintuitive Truth About Roof Crush Standards" (click here).

Where does this leave us ??? We have two competing theories: 1) "better to move around to escape the collapsing roof" versus 2) "better to stay in the seat to survive the flail and prevent ejection". And, this is a hot debate even among automotive engineers and researchers.

What is the answer then ?

Relying on moving around to escape the collapsing roof is *not* a suggested option (possible and it does help *sometimes*, but not recommended) !!! "The performance of restraint systems and structural components is crucial to preventing injury... the roof and other vehicle structures must be strong enough to resist occupant compartment intrusion that can increase the risk of head and neck injury... Good seat belt designs with tensioners that remove slack are important to hold occupants in their seats and away from the roof as much as possible" Source: Insurance Institute for Highway Safety - "What can be done to reduce the likelihood and severity of injuries when rollovers occur?" (click here).

As had been mentioned numerous times already, the real solution is to have the bolstered seat and 6-point harness (a window net too) along with a ROLL BAR.

But, I am sure someone will be along shortly to discuss the shortcomings in this setup too. Things such as "your head will hit the hard metal roll bar"... so, now you need a helmet too !!!

Then someone will be along after that to discuss the shortcomings in that setup too. Things such as "the heavy helmet will cause basal spinal injury in a severe collision".... so, now you will need a HANS too !!!

Then someone will be along to discuss the shortcomings in that setup too. Things such as "the roll bar is not good enough"... so, now you will need a full roll cage too !!!

Perhaps I should get a convertible car, and then I will have no more worries if my roof will collapse during a roll over.

Screw it. I am staying home. What ? Someone is saying that I will get hit by a meteor crashing thru my house ??? If it is God's will, so be it.

[Maximized]

You bring up valid points. I personally wouldn't want to take the risk of myself being harnessed in a fixed back seat IF my car turned over. Roof structures of OEM cars are inherently weak and most of the times I've seen major intrusions in the passenger space in a rollover. If you are in a fixed racing seat w/ a properly worn harness, where is the force going to go? It's going to be placed on your head and spine. That's where a roll bar comes into play, and better yet a cage.

I also think height and seating position play a lot into this discussion. I cannot remember if that was mentioned in your original post. I am 6'2" and my head is fairly close to the headliner of my Mustang. When I open track the car, I sit more upright and my helmet is mm's away from the headliner.

FYI, I had a friend who was thrown from his Bronco back in high school due to not wearing a seatbelt. If he would have stayed in the car, the police and medics said there was no doubt he would have died. One of those rare exclusions to the rule I guess!

[Inaccurate]

Originally Posted by Maximized

I also think height and seating position play a lot into this discussion. I cannot remember if that was mentioned in your original post.

There was a small paragraph discussing this in the opening post (see excerpt below). BTW, thanks for the fair exchange.

"Design attributes that may favorable affect the performance of seat belt restraint systems for rollover protection include seat attributes which lower the occupants body in the vehicle" (SAE Technical Paper No. 982295, page 7). The ability to be mounted low is a feature of the racing seat. Having a lower seating position provides more headroom if the roof did crush. This is an advantage that I gained with the racing seats. With my preferred mounting position for the racing seat, I now sit 2 inches lower than with the oem seat (which had been adjusted as low as the oem seat allowed). I looked forward to having a lower seating position. The oem seat did not lower enough for my taste (and, I am only 5'7").