Roll Cages!

Jonsblckhwk · Post by **Jonsblckhwk** » Thu Dec 23, 2004 2:58 pm

ok after googling roll cage designs and custom roll cages i have made the assumption that rol cages for offroading are designed differently that roll cages for autocross and racing.

im am hoping i am correct as i would hope that i wouldnt have to worry about my 86 rolling i just need mroe frame support and rigidity

so what will i have to pull out of my car so that all the shop has to do is start building?

yes i am that cheap, er poor, because i will probably gut the car anyway to help accomodate the extra weight but i would like to still have a dash and at least 2 seats

BTW the car is an 86 tercel 2 dr liftback 2wd.

my friends dad builds racecars and i think he mentioned something about building rollcages so i might have to get back in touch with him
(he had a very tragic trial with crones disease and missed alot of school then graduated from home school)
hes got a grand national twin turbo BTW damn i love that car

Typrus · Post by **Typrus** » Thu Dec 23, 2004 7:02 pm

2wd? You might want to do a 4wd conversion if you can afford it.
I think the main difference between off-road and street roll cages is the difference in stresses they undergo. In offroading, typically a roll-cage will have to withstand a fairly low-speed roll over but potentially from a significant height. With streeters, they'll typically have to withstand a very high-speed roll over that only under extreme flip situations would have to withstand an inmpact from height. Additionally, off-roading rollovers are nothing major and the car can be flipped back over and off she goes while with streeting, typically the car is toast after a rollover/flipover. I'd suggest something made for strength from speed and the possible flip-over from entering a ditch on icy roads.

Jonsblckhwk · Post by **Jonsblckhwk** » Thu Dec 23, 2004 10:03 pm

well if at all possible id like to just go with something that will be effiient yet inexpensive.
maybe ill just stick with the tubular chassis because i dont plan on rolling over
im not that crazy and the car shoul dbe lowered with bigger rims but an overall smaller tire diameter to yeild better acceleration.
im hoping to get the sma erims and tires that 20vtercel has/had if i can remember correctly. kinda sleepy though

tercel4wdrules · Post by **tercel4wdrules** » Tue Jan 04, 2005 5:01 pm

Jonsblckhwk wrote: hes got a grand national twin turbo BTW damn i love that car

I think that's one car that a souped up Tercel would have a hard time beating. My friend says that a Tercel will probably not beat it, even with a V6 engine that supposedly it has. Dang Buick. :ph34r:

Typrus · Post by **Typrus** » Fri Jan 07, 2005 9:47 am

Heh.. Any recommendations for designs? It'd be nice to incorperate a design that was pratically immune to vertical and torsional loads, but would have strategic crumple zones for longitudinal and horizontal loadings (i.e. crash situations) You might be amazed just how much a crumple zone will relieve in the way of force from the body. Just imagine going from 0 to 60 in .8 seconds versus .05 seconds. Thats a huge gap. Enough to save your life. Additionally, if you have 3000 lbs of force travelling into you, if the crumple-zones absorb 1250 lbs of that, can you imagine the relief on the human body? Better yet, a system that has progressive crumple zones, for forces from 500 lbs up to 2000 lbs. That way, if you ran into a pillar or tree at a slower speed, a good deal of force would still be absorbed. It'd be even nicer if you could find a system system with sidewall airbags and maybe find a steering wheel with airbag and put in all the sensors and etc. Maybe modify it for rear-end impact as well.

Any thoughts?

Typrus · Post by **Typrus** » Tue Jan 11, 2005 8:40 pm

Does noone have more input?

Typrus · Post by **Typrus** » Tue Jan 11, 2005 8:47 pm

placement: (theoretical Utra-stiff cage)

frame behind fender up along a-pillar, follow roofline to back and down to the rear subframe bumper mount - both sides

upright along b-pillar from unit connector U channel to upper bar described above - both sides

upright inline with rear shock tower to upper bar

Connect all bases along floor pan (rocker panels) inside car.

connect front at top of windshield, and top-underside of dashboard

Connect b-pillar and c-pillars

Connect f/r shock towers

Now, you can stop here. Most people do not go any further but you can continue...

place triangular brace from top of b-pillar to bottom of a-pillar - both sides

place trangular brace from top of drivers b-pillar to bottom passenger b-pillar (opposite for RHD vehicles) you can make an 'x' pattern here but it is not necessary.

Do the same at the c-pillar unless you have a hatchback then it's not necessary unless you have a SBC 350 under the bonnet!!!

run tube thru firewall from top underside fender to rad support, allong rad support and back to the a-pillar tube on the other side. Run a tube at the base of the firewall where it meets the frame and run it along the frame to the lower rad support, along rad support and back again. Connect the lower tube chassis to the upper tube chassis with supports where the rad support meets the fender on both sides. Repeat same for trunk area.

Materials that can be used are sched 40 pipe 1.5" - 1.75" dia. (commonly used for usual applications but not necessarily best for your application.)

Full tube chassis....

place tube under vehicle along subframes to connect the two bottom sub-frame sections....that is all you now have a basic tube frame chassis and you can put a bbc 454 under the hood and tub/narrow the rear for a lightnign fast drag car!!!

That was a quote from 20v I believe.

It'd be nice if you could e-mail me a cad and I could potentially put it up. Would photobucket support it?
This really sounds interesting.
Again, I wonder if crumple-zones could be worked in?

20vtercel · Post by **20vtercel** » Wed Jan 19, 2005 3:58 pm

Typrus wrote: Again, I wonder if crumple-zones could be worked in?

Does this not kinda contradict the effect of a rollcage? I always thought that if you had a rollcage, you didn't want anything to happen to you in the cockpit (that's right i said ---- ). Crumple zones would defeat the stiffening of the cage.

Typrus · Post by **Typrus** » Wed Jan 19, 2005 10:49 pm

Ummmmm.... I meant in full tube frame setup and in the cargo area. Not like you'd want to design it so it would crush you in the cockpit, but that the front or back would squish, subsequently absorbing impact energy, taking it away from your body.

20vtercel · Post by **20vtercel** » Sun Jan 23, 2005 8:33 pm

Typrus wrote: Ummmmm.... I meant in full tube frame setup and in the cargo area. Not like you'd want to design it so it would crush you in the cockpit, but that the front or back would squish, subsequently absorbing impact energy, taking it away from your body.

I'll work on a cad drawing. I am trying to find a pic that is broadside so i can overlay it!