Exoskeleton?

March 13, 200620 yr

After rolling the wagon I bought a 4Wheeler rag to show my brother our roll wasn't really that bad, and saw a new-ish Chevy 2500 with a full roll cage on the outside of the body. That would be great because then your body and roof wouldn't get so beat up if ya rolled and you could tie stuff to it. Has anyone, anywhere seen a Subaru with an outer roll cage? Where do you think it would attach?

March 13, 200620 yr

Never seen one, but i can imagine that the added weight would make your car even slower, and would catch on every branch and rock on the trail.

Would i do it, no. would it look neat if you never actually offroaded, sure.

March 13, 200620 yr

An exoskeleton would look cool but by the time you make it structurally sound you have added quite a bit of metal/weight to your Subie. Having tie down points and a industrial roof rack would be handy. Being able to "pivot" around rocks and trees would be handy.

Realistically, If you build a full exoskeleton and you actually roll? Yes it will save the vehicle from most body damage but not all. The real problem begins once you have rolled. The exoskeleton will be tweeked just slightly and may be torqueing your unibody. The problem you have is realigning the exoskeleton!

If you cut just one bar there is a good chance that the whole thing will twist slightly and never align back to the original shape. The reality of it is if you roll you may have to make another exoskeleton and junk the first one?

If your worried about rolling, I'd do an internal roll bar and call it good?

My .02!

Glenn

82 SubaruHummer

84 GL Mad Max

01 Forester

March 13, 200620 yr

Let me give you an example of the use of an exo cage:

Say you are rockcrawling on some serious boulders, and your car bounces a little sideways off the nice line you picked. The only way out is to wait for a winch, or take the line where the rock is going tear your doorskins off on its way to smash the rear quarter window and taillight. Wouldnt it be nice to have a big piece of tubing to take the hit instead, while you power out of the hole? Yes a winch will do the job but thats boring, slow, and lame. If you daily drive your car and do the odd trail every few weekends, an exo is not really the right thing. If you are a hardcore rockcrawler, it is pretty much essential. Sheetmetal catches rocks a lot more than tubing.

March 14, 200620 yr

the main problem as i see it is there isnt going to be much increased safety from a side roll. there wont be any diagonal supports so the whole structure has very little triangularisation.(is that a word) if combined with internal maybe, but seems like redundancy at that point.

March 14, 200620 yr

The biggest problem I can see is that there's no frame to tie it into on the Subaru. Depending on how you anchor it to the body, you might actually do more damage with the exoskeleton than without.

March 14, 200620 yr

A side roll or "flop" during rock crawling usually doesnt involve any cabin intrusion anyways. Like I said, the tubing is there to scrape and pivot on things instead of the sheetmetal. Often a truck with an exo will have bracing going through the body panels, or a seperate internal rollbar to take care of serious rolls. I've seen them in action, and they work.

Making an exo for a subaru is just a matter of distributing the load where the tubing welds to the car. Weld 1/8" plates to the rockers etc then weld the tube to that. this increases the surface area that impact is acting on. Unibodies are very strong dimensionally, in fact stronger than most frames. If you increase the surface area you are transferring the force to the whole unibody instead of a thin piece of sheetmetal.

March 15, 200620 yr

Has anyone, anywhere seen a Subaru with an outer roll cage?

Not exactly an exo-cage but a fun photo none the less. I'm pretty sure I found the pic on S&N Fab's website a few years ago. Guess the Snort guys enjoy subarus too.