removable roll bars/cages

[fatoni]

Originally Posted by NastyNate

I'd love an elise but wont for one reason: Im not paying that much for a car to be powered by a celica motor. Besides, when the miata is paid for it will be a full track car. Moving on I will go up. M3, gtr, maybe corvette, or a v8 genesis. Though I really want a new style supra if it ever vaporizes. Glad I dont have kids so it makes the choice easier and harder.

id take the vette in a heartbeat but a used elise manages to be more fun while not being much faster (read dangerous) all while keeping the cost of consumables down

[NastyNate]

My miata is fun. I want stupid.

[oneday]

Originally Posted by NastyNate

My miata is fun. I want stupid.

Put a roll bar in it without a proper seat or harness and you'll have stupid...oh, wait...look like you are living your dream.



<--owned a track/street Miata with a HD DD bar, FIA seats, and FIA 6-pt harnesses.

[ZDan]

Originally Posted by fatoni

on the street a rollbar increases your chance of injury and increases the severity.

Do you have data to back this up?
I agree to a point, but the question is, what is the actual increased risk?
I think that the added risk (for front-seaters) is often tremendously exaggerated.

a rollbar doesnt protect you from a roll over with a 3pt harness

It's not as black and white as you're making it out to be. I think it's absurd to assume that a roll bar in a car like a Miata can do no good whatsoever in a rollover if you don't have a harness. You're most likely going to be better off with some structure supporting the cabin area in the event of a rollover even with no seatbelt or harness. How that benefit weighs against increased risk of whacking your head on the bar is the question. This will be *highly* dependent on the specific application as well as the exact nature of the incident.

I see a lot of absolutist claims around this issue, very little data.
Show me the statistics regarding injuries from incidents with roll bars and 3-point belts vs. no roll bars with the same belts, in multiple different applications including open cars and older cars with little rollover protection.

Blanket statements are easy to make and easy to believe in. Doesn't mean they are always (or even most of the time) right...

[fatoni]

Originally Posted by ZDan

Do you have data to back this up?
I agree to a point, but the question is, what is the actual increased risk?
I think that the added risk (for front-seaters) is often tremendously exaggerated.


It's not as black and white as you're making it out to be. I think it's absurd to assume that a roll bar in a car like a Miata can do no good whatsoever in a rollover if you don't have a harness. You're most likely going to be better off with some structure supporting the cabin area in the event of a rollover even with no seatbelt or harness. How that benefit weighs against increased risk of whacking your head on the bar is the question. This will be *highly* dependent on the specific application as well as the exact nature of the incident.
%
I see a lot of absolutist claims around this issue, very little data.
Show me the statistics regarding injuries from incidents with roll bars and 3-point belts vs. no roll bars with the same belts, in multiple different applications including open cars and older cars with little rollover protection.

Blanket statements are easy to make and easy to believe in. Doesn't mean they are always (or even most of the time) right...

this whole last page has been about how i dont have any data. were talking about peoples lives here so we cant exactly perform prospective trials. all we have is what has already happened but we cant isolate any variables in a world we cant control.
i will say that at least 95% of people will have their head above the line intersecting the rollbar and top of the cowl and even more once forced away from the seat. a rollbar will only protect things under that line in the event of a rollover

[ZDan]

Originally Posted by fatoni

this whole last page has been about how i dont have any data. were talking about peoples lives here so we cant exactly perform prospective trials. all we have is what has already happened but we cant isolate any variables in a world we cant control.

Actually, there should be enough Miatas with and without roll bars that have been in accidents. I wonder if anyone has tried to assign risk with vs. risk without, that could be useful info...

i will say that at least 95% of people will have their head above the line intersecting the rollbar and top of the cowl and even more once forced away from the seat. a rollbar will only protect things under that line in the event of a rollover

I dont think you can categorically say that. There's no magic line of absolute protection vs. no protection whatsoever. Maintaining more survival space is generally going to improve safety in a rollover whether your head is above a line or not, again the only question (to me anyway) is how that plays against the added risk of whacking your head on the roll bar in more types of crashes.

For most modern non-convertibles, I would bet that the added risk of the roll bar for all types of accidents probably does outweigh any reduction in risk in rollover accidents only. For convertibles, I dunno...
In any case, we're often forced to run roll bars by track and/or sanctioning body rules (this is the case with my cars).

[86racer]

So I am neither an expert on racing or the physics of accidents, but...

1) I wish we would not flame each other, and instead work towards finding the facts so that we can make safe choices in modifying our cars

2) I have reviewed many sites on this subject, and the messages seem pretty consistent: There seem to be two "safe" choices for cars that will be used for both street and track:
A) A totally stock vehicle (from a belt/seat/airbag standpoint) plus a good helmet (SA2010) for events, OR
B) A firmly installed half cage in coupes (or a sturdy roll bar higher than driver's head in convertible, though it seems unlikely to be as safe as a coupe) well clear of the driver's head, plus helmet, plus racing seat with fixed back, plus 5-6 point harness properly tensioned and attached to cage, plus hans all used together for events, but with just the half cage and stock seat/belt for street.

I realize that, while stock safety devices are extensively tested and regulated, aftermarket devices seem to run the gamut from totally unsafe to much safer than stock, and that the aftermarket systems are just that, systems that need to be used together. While a full cage is what is called for in wheel to wheel racing, it seems compelling that the risks to our skulls are high when not restrained by harnesses and helmeted. Many of us are mostly interested in DE and cannot/will not be trailering our cars to tracks, thus my/our interest in alternatives to the full setup.

Fatoni states: "this whole last page has been about how i dont have any data. were talking about peoples lives here so we cant exactly perform prospective trials. all we have is what has already happened but we cant isolate any variables in a world we cant control."

I understand where this statement comes from, but it is incorrect. The IIHS does and shares crash test dummy tests that we can learn from. While I personally have ruled out "racing" any convertibles, I still found it useful to view this clip, because it is easier see what is going on inside:
http://www.consumerreports.org/cro/v...01/6513160001/
From this, I can say that in none of the tests they perform does the driver's head get anywhere near the back of the car (or behind the head rest, for that matter). While this test lacks rollover tests, there are other rollover videos of both live and test dummies, including this one;
[ame="https://www.youtube.com/watch?v=K6h7wqLqJ0U&NR=1&feature=endscreen"]Rollover test 3 cabrio - Test ανατ�οπής τ�ιών cabrio - ADAC - YouTube[/ame]
See 1:03 for why I am so concerned with rollover in convertibles, even with roll bars. I understand that it is not uncommon for heads to hit the roof in coupes, but that's got to be better than hitting cement. Further, I am considering a CG Lock for any spirited drive to keep me lower. But also notice that the heads do not swing wildly to the rear of the car (predictable, given the direction of forces), thus bolstering the stance that a rear cage that is well clear of the seated and restrained head is not going to be hit by the head.

Some have asserted that the problem with any fixed seat in the absence of a full cage is that the roof could collapse in a rollover and leave your head as the highest point. I have even seen assertions that the stock seats are "designed to collapse." My conclusion so far is that stock seats are NOT designed to collapse (I have seen no reputable reports to that effect, nor videos of them collapsing). I also conclude that coupes are safer than convertibles in this regard, as are newer cars vs. older cars, and that a rear/half cage is likely less effective than a full cage, but likely still better than no cage at all -- and since I am considering mixed usage cars in which full cages should be avoided, it seems clear to me that a half cage in a newer car is likely the best solution.

I bet there are differences in stock rollover protection for various cars, but I have so far been unable to source those ratings.

Consumer Reports weighed in on Rollovers:
http://www.consumerreports.org/cro/2...-101/index.htm
From this I infer that newer cars are becoming more crush-proof, but I was also dismayed to confirm that "Safety belts are not required to hold occupants in place during a rollover. As cars roll, occupants are pulled out of their seats and toward the roof. Most safety belts in use today won't stop that," thus my interest in CG Lock or full Harnesses. Of note, the IIHS Rollover test is not dynamic, but instead loads the roof with weight:
[ame="https://www.youtube.com/watch?v=-IwOwog3skk"]Tiguan Rollover Crash Test - YouTube[/ame]
Another site with advice on avoiding rollovers:
http://www.safercar.gov/Vehicle+Shoppers/Rollover/Causes

Oh, and on the subject of race seats, I am convinced a Halo seat offers superior protection for the helmeted and harnessed person, especially for side impacts and rollovers, but would be wary of using it on the street:
http://forums.bimmerforums.com/forum...at-Halo-or-not

That's it for now. for reading, and for any constructive comments on this subject.

[mad_sb]

@86racer , I'm in the same boat as you. I'm looking into a custom weld in back half cage. I will probably continue to use the stock seats (air bags yo!) so i will be limited to either a road legal (has a red push button release) 4 point ASM harness set (Schroth Racing Profi II ASM FE Harness) or just a regular 4 point ASM (Profi II ASM). Probably the latter and keep the stock belts in the car for road use.