Update: building a roll cage

[widebody911]

Started building the cage last night. My friend with the tubing bender had a kid-soccer obligation, so we got started late. 6 hours and 60' of tubing later we got the main hoop and the two side hoops done. To be fair, it's been a while since he's done any bending, and we were making some mistakes which in retrospect were just plain silly, like cutting too much, bending the wrong way, or flat out starting with a piece of tubing that isn't long enough. Now I get to do some massaging at home to get the side hoops in place, then go back and do some smaller bends. The main hoop is just lightly tacked in place for now.

[hkspwrsche]

What kind of tubing is that? Are the brackets for the convertible top still attached on the Quarters?

BTW someone else that has a targa is asking about widebody conversions on another thread just below..

[widebody911]

The cab brackets will stay in, but later I'll cut the seat belt mount off of them; right now I'm using the holes in the mounts in conjuction with monster zip tie to hold the fiberglass top on!

The tubing is 1.5" x .095 ASTM A513 Type 5 DOM

[MichiganMat]

lets hear some details on that buggy in the back!

[widebody911]

Took some more cage pix last night.

The buggy in the back is one of my friend's 'long course' desert racers. It has a V6 Vortec (sp) engine with a VW bus 091 transmission. He builds these things himself, I think he has 4 different ones right now. He might be persuaded to give a tour when you come up here, Matt.

[RickM]

Nice work. What kind of tubing/pipe bender are you using? One of those hydraulic jobs with the dies for different angles?

[widebody911]

This is the bender: http://www.vansantent.com/model_3_bender.htm

[Tyson Schmidt]

Thom, make sure you support the chassis in the middle when you weld on the car itself. If you don't, the chassis will close up. The door gaps will tighten up, and the chassis wil sag.

Especially if you plan to weld the cage in. The cage shrinks when it cools down, pulling everything in. So you need to flex it the other way beforehand by supporting the car in the middle near the jack-points.

You don't want to drive a banana!

[Zeke]

Tyson speaks the gospel. Not only support, but hold. It might not be so bad to drive a banana, but a banana that won't corner balance would be difficult. so, you have to make sure that car is not tweaked when you weld.

Brad Roberts, of 914 fame, has jigs for the door openings that bolt to the top hinge mount and over to the door strike mount. They are adjustble and can pretension the tub. While his are fairly complex, I don't see why they couldn't be fabbed up with the materials you have there laying around.

Very cool Thom.Here is a couple of shots of Tyson tack welding a roll bar for his old car which was a cab. After it was sized it was taken out and welded. Also you dont see that he made brackets to bolt it to the top seatbelt bracket. The horizantal bar is removable when not being used for the track. The whole thing was powdercoated at the end.

[BigD9146gt]

Thom, nice work! Thats the same bender i got too, that DOM is hard to bend! I had an extra ratchet arm to hold the drawing arm after each bend, otherwise the spring back would keep me from ingaging the next tooth. Did you get extra non-DOM to practice? Or did you go through 60ft of DOM???

[widebody911]

We did some practice bends on 'cheap' ERW stock, but still managed to blow though a bunch of the expensive stuff. I can salvage some of the mis-bends to make smaller pieces. All my friends are getting DOM tubing paperweights this xmas.

I had a little of the 'pull' issue when I removed my improvised door bars - I got a little bit of 'twang' when I cut them off and the door gap changed.