Safety mods?

[Cd]

Originally Posted by Frank Lee

You want the hammer for when you drive into bodies of water and want to break a window to get out. Me, I try to use only boats for that.

Tell that to this guy :

http://www.youtube.com/watch?v=M4Usx...eature=related

I'm glad that i read through this thread. Reminds me to test the fire extinguisher in my car.
I also have a first aid kit as well.

I'm surprised by the comment on roll cages. I would have thought that a roll cage would stiffen the structure.
As far as cracking your head on the roll cage, I assumed that since the structure is stronger, it would crumple less around the cabin and you actually would be safer, like this guy :

BTW I just love that engine sound in this video !

What I am pointing out though is the very last part of the video where they show the car. The car looks to be pretty much stock body wise, yet the cabin is still in one piece.

http://www.youtube.com/watch?v=TTzbBRyOO0o

[some_other_dave]

Originally Posted by Cd

I'm surprised by the comment on roll cages. I would have thought that a roll cage would stiffen the structure.

It does--noticeably.

As far as cracking your head on the roll cage, I assumed that since the structure is stronger, it would crumple less around the cabin and you actually would be safer, like this guy...

IF you have a helmet on, and are in a good supportive racing seat, and you have five- or six-point harnesses on that are snugged down tight enough that you cannot move your torso enough to reach the radio, or to turn and look over your shoulder, then you will be safer in a roll-over and possibly other collisions. If you are wearing a stock seatbelt, you will move around in the cockpit an awful lot--more than enough distance to smash your head into the top brace shown in the video, for instance. But stock belts let you tune your radio, look over your shoulder to back up, turn your head to check your blind spots, and all of those other things you really do need to do when driving on the street.

This is yet another way that a race car is different from a street car, and another thing that applies to the one but not to the other.

Roll cages are DANGEROUS on the street.

-soD

[Cd]

What about a tube frame chassis ? It would certainly keep the car intact in case of a crash, but all the shock would be absorbed by your body instead - right ?

Surely there has to be something that we can use from F-1 racing that would make our cars safer ( anything ? )

[Cd]

Originally Posted by some_other_dave

It does--noticeably.



IF If you are wearing a stock seatbelt, you will move around in the cockpit an awful lot--more than enough distance to smash your head into the top brace shown in the video, for instance.

-soD

Yes, but even without the cage there, you would be instead smashing your head on the metal frame of the A pillar.

It seems like a cage could be designed with enough clearance to not be so deadly in a crash.

[SlideWRX]

Any pillar in a car these days that wants more than a 1 star rating is covered in plastic trim. It doesn't look or feel soft, but compared to metal it is *much* better. Most pillar trim has space or ribs behind it to absorb the impact energy.

Take a look at crash tests on you tube to see how far a person belted in moves around in a crash. It is surprising.

http://www.youtube.com/watch?v=d7iYZPp2zYY

[Creeper]

If you want to be seen LED tail lights are an option as for headlights you can try making a set of LED's or getting a set of Halo light real halogen not the white lights all be it that if you do not have projector housings you blast the light everywhere and while people do see you they can't see with the lights. Avoide a roll cage which can be used for a 4point harness unless you use the car for racing a Import Tunning did a studie on this a few years back and a roll cage with 4-5 point harness could kill you in a crash as it will be a difficult to get oiut of the car once in a crash and if its on fire as well as knocking you into solid steel tubing might break a few bones.

You could upgrade your brake system to large brakes with bigger calipers and an upgraded pump system to supply the proper break pressuer to the calipers you would also need to upgrade the lines to braided lines to handle the pressure. Slotted rotters would help with distributing the heat of the braks cross drilled are prone to cracks. I know a read tires are big as well good tires with decent to allot of grip will help you stop.

If you get stuck on the side of the road with a flat and its a highway try limping the car to a spot where you can get out safly i.e. where there is no gaurd rail only you and a grass median would be safer. Yo would chew your tire but it would be safer then the alternative. Keep a sup[ply of road flares and a repar reflecters along with your hazards on so you do not get hit. Thats mostly how I would emprove a vehicles safty.

[some_other_dave]

Originally Posted by Cd

Yes, but even without the cage there, you would be instead smashing your head on the metal frame of the A pillar.

It seems like a cage could be designed with enough clearance to not be so deadly in a crash.

The A pillars today are designed to be far enough from the occupant that this is not really a concern. A roll cage is designed to fit inside of the rest of the car, so it by definition will be closer to you.

Roll cages are specifically designed to be part of a safety system, which includes a good supportive seat and very tight multi-point restraints.

You could design a cage with enough clearance to not be so deadly in a crash. It would be built into the rest of the car, and it would look a lot like an A-pillar, a thick roof, and so on.


A full tube-frame is expensive to make. A mass-produced car built with one would cost an obscene amount of money, at least with the way they are currently built. Perhaps in the future...

There was a trend in race cars for a while to make the car as strong and stiff as possible. It turned out that the driver then started taking all of the impact, which predictably wasn't so good for him. So they changed over to deformable structures which crush and dissipate energy that way. A lot of the race cars were built to practically disintegrate when they hit something hard enough, because each piece that left took some kinetic energy with it when it did.


Safety systems are indeed systems. They are designed to work together; when you just patch things together piece-meal you may improve things or may make them much worse.

-soD

[Creeper]

The only other problem/anoyance I could see to safty mods as these and this is coming from a custom car builder is the police. Once a cop looks at your roll cage you will be pulled over and frequently.

[fjasper]

Something I've noticed on my newer car that my older, similar model didn't have, is that the empty spaces in the body structure have been filled in with heavy-duty styrofoam. It's like the styrofoam in a motorcycle helmet-very stiff and hard. Presumably it's there to absorb additional energy by compressing as the structure collapses.

As far as retrofitting, it seems like it would be almost impossible to predict exactly what effect it would have, although you could probably guess that it would increase the rate at which energy was absorbed (more energy absorbed per unit of body deformation), and on a car whose safety performance might be improved by this, it might be helpful. An awful lot of guessing and conditional language in that statement, though.

Small unibody vehicles seem like they may benefit from this treatment. It seems like it would allow the structure to absorb more energy in the limited amount of distance available to compress. It would increase the G-loading during the compression, though, increasing the forces on the occupants.

Probably not helpful for body-on-frame units, where the problem may be that the structure is already too stiff.

I haven't seen expanding spray-foam that looks like styrofoam when it hardens, but I suppose it might be available.

[Phantom]

Here is a bit about adding expanding foam.
Project S13 Nissan 240SX