How to: 4 Point roll bar (cage), with rear seats still fitting!

[Nategreat923]

For my senior project Im building my car to drift. This includes 5 speed, welded diff, coilovers, bucket seat and last but not least a SCCA approved 4 point cage. Heres what a local shop (LakeTown Motorsport) and I did.

Started out by gutting everything from both interior and trunk.

Next we decided where to mount the 6"x 6" Floor plates for the main halo. My main focus was trying to keep the rear seats in, so we decided to tuck them as close to the speaker brace area to keep the clips for the rear seats in.

Next, we chiseled out the sound deadning to the appropriate area for the plates. Then we removed the clips for the rear seat so we didnt melt them while welding.



Then we took a grinder to the floor to smoothen it out, along with hammering down the little lip that sticks up from the floor.



Next we did a lot of measuring to see what bends we needed along with measuring angles.



(I can get exact measurments if you'd like.) After we bent all the tubes, we tack welded the 6" x 6" plates to the floor, then the main halo to the plates. Awesome fitment!



Next, we cut off the side panel bracing for access to welding the support bars.



Next, we made a cardboard template of a box to weld onto the wheel well, it looked like this:



Tack welded that in to test fitment, and turned out very well.

After that, we made the support bars (with some notching and a lot of grinding) and eventually got them perfect. Tacked them on good and ripped out the halo and support bars (still connected to each other).



Then we welded the cage together, then welded the 6" x 6" plates in fully, and fully welded the boxes on the wheel well on. (Be very careful not to catch the top on fire!)



Then we welded the cage in!



Then put the rear seats in!

[-RJ-]

lol thats pretty sweet, but why would you want backseats with a roll cage? that seems dangerous on normal driving applications

[Nategreat923]

No one will be in the backseat period. Its just a lotttt cleaner looking.

[KLYPH]

Thanks nate!

[noobdrftr]

thats pretty cool...are you painting it?

[Nategreat923]

Maybe. maybe not. If I do its going to be a dully glossy white or black.

Rear panels fit still too.

[240daveTX]

Maybe. maybe not. If I do its going to be a dully glossy white or black.

Rear panels fit still too.

can you post the measurements up

[Nategreat923]

Ill get them for you tomorrow.

This is rad:

[streetstarspride]

pretty dope

think about doing a harness bar?

[Nategreat923]

Yessir. In the next month or two, along with door bars.

After that, the carpet goes back in!

[streetstarspride]

sweet.

i don't know if your into aesthetics more or function of what you do.

i like both, for a mod to function and to look nice.

personally i'm going to re-upholster the door card inserts and the rear seats if I'll even have those.

goodluck with the build

[mmm240]

Mad props dude! Can you even fit a finger between the top of the cage and the top?

[PyR0NiAk]

lol thats pretty sweet, but why would you want backseats with a roll cage? that seems dangerous on normal driving applications

i don't see why you think it'd be dangerous for people in the backseat... you have one bar by your leg... he can put styrofoam around that... as far as the head area.. it's no worse than riding in the back of a 1st gen dsm.. i'll never forget.. anytime i would accelerate hard in my dsm my friends in the backseat would always smack their head...

[fresno240sx]

that is tight! looks very nice and clean with the roll cage.

[Piper]

Looks nice, besides those dings and dents on the tube. Sort of screams, "left over pipe!!"

But besides that, some door bars and a harness bar would look sick!!

[Eikon]

Great work!!!!

[onosqv]

Cool senior project - high school senior project?

I'm no engineer, so perhaps you or someone else could explain...

The mounts/plates that the rear roll bar legs go on doesn't seem that safe to me - even though it's flat for the bar, the actual contact patch to the car chassis is just the outline of the mount you made - seems like it won't distribute the load that well (like how the front legs are mounted) vs a flat contact patch during a roll over.

I'm imagining something like if you just sledge hammer that part of the car (flat contact patch) vs hammering w/ a chisel @ the same part of the car (kind of how your rear mounts are done up).

That being said, I love how much clearance you have in the rear seat area.

EDIT: And since you are building an SCCA legal bar, what material bar sizing are you using (my buddy said it looked like ERW)? and there's dimples/dings on the main hoop? Don't think the material you are using is SCCA legal. And I believe mounts have to be fully welded on all 4 corners (doesn't look that way w/ the rear legs right now).
Modified by onosqv at 11:53 AM 5/13/2009