Are half cages really worth the time, money, effort?
 

Are they going to do anything in a rollover? I know this is open to many variables but assuming you've flipped and land on the roof I don't imagine the windscreen is going to stop you from getting severely injured or worse.
Opinions?

Generally no. They are a good mounting point for harnesses but will not hold up very well in a serious crash. There are a few well built and strong bolt in options out there for some cars though. GMG makes a pretty nice one for the GT3.

So really they're just a glorified harness bar? I suppose the likelihood of flipping is much more when racing vs time trials, but probably better to be sure than sorry.

I disagree to some extent (BTW, I used to have a roll bar but now have a cage).

IMO in principle you can look at them like "roll bars" in an open wheel cars, they don't have windshield either. If you draw an imaginary line from the top of the roll bar to the top of the hood (or maybe fenders) of your car, that line is what is "between" you and asphalt when you're upside-down.

I'm not really any kind of safety expert, just an uneducated opinion.

They are far better than nothing at all. In a flat crash (ie no roll) the can at as solid mounting for a harness. In a roll over they will protect the b-pillar from collapsing and since your head is near the b-piller they will help protect you. They are not as effective as full cage, but I think a excellent compromise for street driven cars as you get good benefits, but much less chance of head to bar contact on the street.

Hey;

Let's break this down a bit into two main areas of incursion.

To the extent that the rear roof area stands to come DOWN, they are then useful, and obviously desireable. That extent is usually minimal in reality. The most vulnerable portion of any car roof - by far - is the distance between the cowl and the b-pillar, the longest unsupported length of metal in any car, even with a cage. Taking steps to buttress this area is ALWAYS a good idea. To wit;

http://www.redlinerennsport.com/06_D...ning_Boxed.jpg

Where they stand to do you the most good is in keeping the roof from mashing SIDEWAYS. This is where the rear roof area is most vulnerable. The extent to which a roof will mash in this manner is the result of how it rolls, and generally the result of the speed at which it rolls.

"Soft" rolls will not effect it too much, but a flip and roll is much worse. This is where the wheels catch and actually launch the car airborne for a time, when it then lands on some portion of the roof. Even a soft roll at higher speeds - although creating less rotational force - will see the car airborne for a short time. The landing point is most often on the door frame/drip rail area, and the results of this can be significant, given proper circumstance. The top of the windshield area is usually a secondary stress point, and is not generally subject to the high highest loads.

This car rolled on pavement, and the results are clear.
http://www.redlinerennsport.com/fliproll.jpg

So, are they worthwhile. I'd have to say yes!

^^^ What model Porsche is that John??:D

For a car you drive on the street, I think a half cage is the best you can do. The front hoop is not a good idea on a street car. A good Roll bar with supports going forward across the door will make it very strong and even in the almost impossible event of the A-pillar crushing, your head should still be safe.

Also depends on the car. A former GF of mine hydroplaned, flipped, and rolled a Miata at about 70mph. despite sliding on the windshield frame for a bit she walked away without a scratch. At an autocross a few years ago I saw a fellow flip and roll some form of Honda (I think a Prelude?) with a bolt-in roll bar and the A-pillar buckled quite impressively, probably because he slid on it for several yards. Driver got out and walked away. "Modern" cars are specifically designed withthe idea of a high-speed rollover in mind, and the A and B pillars are among the strongest points of the car.

IMHO, a Roll Bar is fine for what it is intended for, IE when the vehicle rolls over- if this is your biggest concern, then a roll bar will do. It does absolutely nothing to help in the far more likely event of contact with another car and/or immovable object.

Hmm. This is in a 951 which 'feels' like it's a very solidly constructed car, but....
It is a highly modified street driven car and it will be a very quick car soon with approx 500hp. The events we generally participate in are what we call Super Sprints. This is a timed event on a track over 6 laps where you run in speed groups but not side by side. Overtaking is permitted on straights or if signaled by. The chance of contact with other vehicles is remote. Still, anything can happen.
So the general feeling is a half cage is better than nothing. A full cage is best but there are concerns in a street driven car. Can't these concerns be surmounted?

Full cage for you my friend! I have a standardized rant about how the true tragedy is not if you die in a motorsports accident, because then all those who love and care for you mourn a bit then move on with thier lives remembering you fondly. The true tragedy is if you are injured horribly and must spend months or even years in recovery or worse- live out the balance of your life as an invalid. Then all the ones you love and love you in your life have the task of taking care and providing for you the balance of your existence, becoming a financial and physical burden- imagine needing to have an adult diaper changed the rest of your life because you skimped out on a rollcage! I for one, wish that on no one I love! I doubt I am wrong in my guess that you are spending a fair amount of coin building your high-horsepower track monster, and are possibly balking at the idea of spending a fair amount on the safety side of things now. Well, DONT! Spend the money to protect your life and your health.

With good planning and construction there is no issue with a rollcage for a dual-purpose car. Do it right, or buy a Prious.

The issue with full cage on the street is head trauma during a minor front impact from contact of the bare head to the cold steel of the cage. Roll bar padding helps, but steel is very hard and heads are soft.

On track you have a multi-point harness and helmet to minimize that risk.

Really? Because in my car(s) with roll cages when driven on the street the 5-point harnesses are used, no OEM belts exist, and all bars within range of the drivers head are covered with padding as per the rules, and to be honest if the debate is going to be increased street comfort VS on-track safety in a 500WHP car the issues are clearly screwed up. Yes, there are lots of 500whp cars out on the street without cages, but they are not turning competetive laps on a track, which is where you are far more likely to screw up and put yourself into serious risk! And FWIW if you arent wearing your belts on the street you deserve whatever you get for being an idiot.

This is purely guessing right.

No studies have been done to show this one way or the other.

Remember that tehre is some flimsy moulded plastic covering steel at the A and B pillars in cars. I gotta say that some SFI wrapped bars sound a bit better to come in contact wtih than cheap plastic covered Steel. Just my opinion of course.

Flying Fin wrote: I have seen you drive; You definately need a cage :thumbsup:


My other trackcar is a '01 Mustang GT and I have a "light" (from the roll bar forward 2 bars forward along the roof to the A pillar, down through the dash and 2 bars back along the floor back and 2 diagonally going up to mid level on the roll bar.) cage because it is built weak (Think pudding) and will flatten.

A new GT3 can also crush, but with a techquipment roll bar above my head and sitting with my head next to the B pillars (6'4"), so that all airbags can still deploy, I feel safe enough. These cars are pretty well build.

Still if my car would have come with an RS bar, I would have put the forward part in also, seems drivable enough to me on the street.

The Mustang was also a daily driver, you get used to it.

My cage has more padding than my stock A and B pillars did before the installation (a thin sheet of vinyl will do far less to cushion my head than the sfi high density cage padding). By lowering my seat and mounting it 2" closer to the tranny tunnel, my head position is now far further from my cage than it was from the roof and A/B pillars in the stock configuration. I'm not a safety expert, but I don't really see why there seams to be such passionate feelings about how reckless it would be to drive a car with a cage on the street.

I should clarify that while a bolt in half cage is of course better than nothing, just get a true cage if you are concerned about a rollover.

How much do you guys pay for a good custom cage? We get quoted stupid amounts out here. $7-$10k!
I do think I will have to relent however as I agree that nobody should have to put up with me in a wheelchair.

quotes vary from $2000 US to $7000 US depending on type of cage, materials, builder, prep work, etc. I paid $2500 US for my initial cage, but since have added extra bracing and tubing that would have put the cost at more like $3500

as mentioned I would put in a full cage from the start

Ha!

You can argue this six ways from Sunday, and it is way more complex a topic than can be done justice to on this forum. It's been discussed before. Suffice it to say that - whether the stock vehicle is "safe" or not (and they HAVE been tested) - adding tubing to a street car is not necessarily a good idea, and it would be a miracle if it did anything but lessen your chances if you clonk it. This coming from someone who has inspected and investigated more wrecks than everyone here combined, times 10. You can take my word for it... or not.

You can wear your helmet on the street. You might expect to get pulled over, though. If you wear your harnesses, you might get a ticket. Most are not D.O.T. certified, if you didn't know.

In the end, it boils down to managing your risk. If you think tubing is your savior, then have a go. I'll take your money and build you a great cage. Won't even try very hard to talk you out of it. If you don't want to take the risks that adding tubing to a street car offers, then you better drive within a reasonable limit with what safety equipment - and ability - you do have.

You should hold the image of that wheelchair in the deep recesses of your mind no matter what you decide, just to keep it real.

7-10k Aus $ is a good price! Every race car i've had built has been upwards of 5k US for the bare minimum!

$7-10K USD.....damm thats steep!!!! I was quoted $2000 for a custom 8 point cage out of 1.75x.120 DOM for my race 928 that is under construction....right now only the back half is done....but the rest should be done in a month or so

SFI padding is pretty hard if you don't have a helmet on!

Do it, don't do it, do it, don't do it????

That's Aussie dollars but it's all relative. It costs a lot. I tend to believe that uncovered steel sills in the car present a big enough potential issue in a crash on the road (or track). I do wonder if a cage is correctly padded how that would not be more forgiving than the standard cabin internals. Of course you do bring the cage closer to the head and perhaps that increases your chance of impact?

Maybe but that is not necessarily unsafe. Think about a full containment head halo seat. If those where SFI padded bars instead and you hit those you don't have the same kinetic energy buildup if you hit the same padded bars it they were 8 inches away. Think about what happens to a baseball when you hit it on the sweet spot vs. a screw up closer to the handle.

I'm a long way from an expert, but...

I believe a cage makes a street car much safer no matter where it's being driven or what equipment the driver is wearing. In all the years I've seen these discussions take place, I've seen ample amounts of evidence of rollovers/incursions/etc where the cage provided a benefit. I've never seen anyone with actual evidence (or better, an actual study) that shows any significant number of drivers hurting their head on a cage. In fact, I've never heard anecdotal evidence of it happening even once.

That isn't to say a person's head wouldn't hit an SFI-padded cage in a collision, but -- as ninjabones points out -- it's not like the A- and B-pillars are made of fluffy cotton. Just as a crashing car doesn't know whether it's on a track or a street, a piece of steel doesn't know if it's part of a cage or a chassis when it slams into your head. And at least you can pad a cage.

Do you really think Porsche (and other companies) would include cages in street cars if it made those cars significantly less safe in street driving? The big, unpadded roll bar was included on my 1983 CJ7 was part of a safety package conceived after repeated lawsuits forced AMC to completely re-engineer the patently-dangerous CJ5.

And for those of you who pretend that your head isn't going to move far enough to hit the rolled roof edge, A-pillar or B-pillar, I'd suggest you talk to an experienced EMT about how far the body and head travel in a collision. I always tell people to imagine a sphere that extends 24 inches out from your head in all directions. Everything in that sphere is fair game in what most of us would consider a low-speed impact.

Right On, FBB!
--------------------------------
Well...

To try and simplify it greatly, it is about deformability, and surface shapes.

Deformability - Take a sledge hammer, smash it into a stock roof pillar, and then a cage hoop. Which one deforms more? Simple. Whether replacing the hammer with your head offers a survivable impact in the case of the stock pillar is highy debatable, but the theory behind it is sound. Cages are hard, even with the proper padding. I have seen stock roof structures deformed from human impact. I really don't have to guess in the case of tubing.

Surface shape - To the extent that any stock roof structure represents a smooth, more uniform shape, it is safer than a tube. If your head gets squunched into a tube, you would hope to do so on-center. Any impact off center enters offset loads into the body, which is harder to survive. Also, the small surface area of a tube offers a far higher focal point of energy than a flatter surface.

As to how far a body travels, I'll tell you. On average, your hips will move 4-8" and your shoulders 12-18" in a "normal" impact of 40g or so. Your head will move farther still. THAT IS WITH A RACING HARNESS! In anything but a straight forward impact, your (unrestrained) head will almost certainly hit something. With a 3-point belt, you would be stunned to see the range of motion. Significant portions of your body will be biffing something in this case. Air bag, please!

This may be all based on conjecture and surmize, but the ideas behind why tubing is not necessairly safe are sound theories, and what car makers have or continue to do has nothing to do with that. Even if they are aware of the possible eventualities (and that is a HUGE if, depending on the era), they are playing the odds just like we are.

I will not tell anyone not to put tubing in a car, I will simply make them aware of the possibilities. It is down to everyone to make their own assessment of their own risk. Knowing the possibilities is an important part of making an informed judgement.

Well I appreciate your thoughts on this subject guys although I'm no clearer as what to do? It seems like the age old line in the sand and having to crossover that line to commit to making a racecar. Pity about the funds :(
What about wearing a bicycle helmet when driving? Apart from looking like a dickhead, would it offer any assistance in an accident?