Cage design outside the box

[JustinOlson]

 

How is a 240z with a full cage less safe then a new jeep wrangler? You have the same risks as that. I would think that high density foam would go a long way in a fullcage 240z.

 

The only thing I can think of is the diameter of the roll bars in a jeep are larger then a standard cage, so there would be more padded tube area to distribute the impact over. This would lessen the peak force on your head in an accident.

 

Justin

[JMortensen]

The Jeep was designed with a tall, square top so the bars are much farther away at the corners of the roof. Plus a Jeep doesn't have door bars, and the main hoop is far enough back that it would be hard to hit, judging from your picture there.

[JustinOlson]

FIA padding looks like it would be the way to go:

 

"

SCCA, NASCAR and many other sanctioning bodies now require certified roll bar padding on any member of the cage that may come in contact with the helmet. They recommend it use on any member where the participant's body may have contact.

 

 

 

Roll bar padding is not just roll bar padding. Tests have proven that roll bar padding plays a vital role in decreasing the potential of serious injury in crashes. All drivers should be surrounded with FIA Type A ,or SFI 45.1 Spec Approved Padding.

 

FIA padding is thicker than SFI padding and can absorb about three times the impact."

 

http://www.rallylights.com/BSCI/Roll_Cage_Padding.asp

 

 

Another interesting link I found while search was a video of a crash test with and without a HANS device:

 

http://english.schroth.com/engineering/versuch.php

 

Man, I wouldn't want to wear a helmet without one.

 

Justin

[bjhines]

That jeep roll cage is an interesting point....

 

But keep in mind that the bars will be MUCH!!! closer to your head in the 240Z... in fact... most people end up with the roof/A-pillar bar practically touching their head while seated in the car...

[johnc]

How is a 240z with a full cage less safe then a new jeep wrangler?

 

Federal Motor Vehicle Safety Standards 201, 208, 214, and 216.

[JustinOlson]

http://www.nhtsa.dot.gov/cars/rules/import/FMVSS/index.html

[WHP]

Good stuff, thanks guys, it got a few new wheels turning in my head.

Will Piatt

[mom'sZ]

FIA padding looks like it would be the way to go:...Justin

I just got some of the FIA approved padding from the source linked in Justin's post. (thanks Justin!) This stuff is not exactly what you might think of as padding. It's pretty hard! It's also quite stiff. Might not bend around tight curves. In an accident I'm sure it would hurt less the an unpadded bar but smacking an elbow against it in the tight quarters of a caged Z would probably smart. Not cheap either

[jonnymrp]

im planing a 6 pt. cage build similar to what i being talked about here. im want im put on what diameter and wall thickness tubeing to go with any sugestions

thanks for the help

jon...

[2ManyZs]

For anyone who thinks the Jeep Wranglers have a safe full cage, take a look at the slideshow of this recent accident, especially picture number 9.

 

http://www.nbc4.com/newsarchive/10479153/detail.html

 

It might be safe in a low speed, off road rollover, but don't think for a minute it's a safe cage at highway speeds. The front half of the cage peeled back, the shoulder straps holding them into their seats were attached to the cage, and both of them were thrown from the vehicle.

Sadly, the parents of these two teenagers probably thought it was a safe vehicle for a high school student to drive.

 

This is a good example of why a solid chassis is required as a foundation, well thought out mounts to the chassis, and most of all, a competent welder needs to do the installation.

[260DET]

This one is in a S130/280ZX coupe which will be used for road and circuit. The design was subject to AU road legal constraints, the door bars can't obstruct occupant exit for example. The hoop locates behind the driver's seat so head contact with any bars is unlikely while the hoop V brace allows good rear vision.

 

Note that the hoop is tagged into the body at several points to increase body rigidity and that there are other (hidden) structural additions.

 

[WizardBlack]

Roll cage padding help in an actual collision? LOL I seriously doubt it. It will do nothing more than slight dings when being thrown around while the car is buffeted or rolled. If you actually hit the bar, you won't hardly notice the difference.

On a side note, the welder is absolutely critical to make the cage a device of safety and not more risk. I have seen homologated cages break apart in a crash and the ragged pointy end of one piece of the cage actually pierced the driver and made a nice sloppy 2" diameter hole through the person's body in several spots.