City Baja Build

[Big Bus]

Volksmeister , with your rollcage , dont weld on your base plates yet , and holesaw a hole through the floor under the plate with the roll bar tube outer dia , which will enable you to drop the roll cage legs through the floor , enabling you to weld the top sides of any joints .

[Volksmeister]

Erik- I know what you mean... I am making a fast recovery(faster than the first ) Just have to be careful.


Big Bus- That is the current plan!

[Leatherneck]

Volksmeister , with your rollcage , dont weld on your base plates yet , and holesaw a hole through the floor under the plate with the roll bar tube outer dia , which will enable you to drop the roll cage legs through the floor , enabling you to weld the top sides of any joints .

What a bangup idea.

[Volksmeister]

Hi all. Update: Back in the saddle again!

At the start of this year I had a huge wrench thrown into the gears of my life and really f-ed me up in so many ways. But, time has passed and now I have motivation and desire to work on my projects again! I have been making good progress the past 2 weeks.

So, a few weeks ago my buddy Aaron and I bought a baja with no motor or decent wheels or rear brakes and a rusted out pan. Aaron needed a titled body for his car and I ended up with the one-piece front end and mount, front/rear suspension, fuel tank. I also snagged a set of T3 wide-5 rear brakes from the seller too!

Mean time I have been fitting and installing the roll cage with success. Let me know what you guys think. I am on the right track? Feedback on my sketches would be appreciated... Especially on the rear section of the cage.

I will shut up now and let the pictures do the talking

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This is the car we parted out. put his motor, tires and fenders on it so we could take it for a spin.

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I am still trying to figure out how to tie in the angled support from the bottom of the bumper to the cage. If that bar onds up being in the way I may just scratch that whole idea.

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Cage dropped through holes in the floor to fully weld around tubes

[Volksmeister]

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This is the nifty mount for the headlights and the one-piece front...

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The fuel tank filler will be in the quarter panel below the side window.

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My beam was bent back on both the RH and LH side... In the process of building up another one. It also turns out that the frame head is bent back on the RH side about a degree. I plan on shimming out the beam to correct for that.

Thanks for looking

-Levi

[CentralWAbaja]

Nice progress Levi

Glad to see you back in action

[Ol'fogasaurus]

Volksmeister: On your sketches you have showing your cage design the door area. In my opinion (and it is worth less than what you paid for it), if you take a front end hit (causing the pan/cage to possibly flex) or a high hit such as a roll on the front like in the windshield area (that hidden line you have marked remove?) could possibly either flex the diagonal tube or bend it enough cause it to fold/collapse. Gussets (plural), if properly placed, may help move/transfer most of the load up and down the tube but I think you need a tie the other side of the hidden line to the floor. Hinging the dotted line/tube for entrance might work, as long as it is tight in place and properly anchored at each end, a down/angled tube is under the diagonal for support. (I hope this makes sense)

As far as the rear goes, I am not completely sure what I am seeing... sorry.

By-the-way what you drew up using a VW in the background is a good way of presenting an idea. Good job!

Lee

[Volksmeister]

Thanks guys!
Lee
, I didn't like the idea either of a tube dead-ending at the span of another. What I am trying to do is to make it easier to get in/out of the car. I hope to figure out some kind of removable 'door bar'.

As far as the rear goes bumper goes the sketch is showing 2 options for the terminating the angled bar from the bumper up to the cage. It will either tie into top tube of the bumper or the tubing at the bottom of the baggage compartment.

[Ol'fogasaurus]

Oh... the word was "OR...", I thought it was something else as it was fuzzy. Sorry; I went back and looked at it again and now it does make sense.

Are you going to get a bender involved in this or is it going to be pieced together?



This photo came out of Central WA Baja's build, around page 7 out of a whole bunch of pages (http://www.shoptalkforums.com/viewtopic ... 8&t=129794) and is why I was asking about a bender. It is another way to look at the problem. I recommend looking at this build string as a whole, not because it is a long and good build but there is a lot of discussion on many different aspects/details within in it. There are also some other great builds in the “build threads” folder on the off-road forum http://www.shoptalkforums.com/viewtopic ... 8&t=136758.

Lee

[CentralWAbaja]

I probably went a little overboard on trying for style points

lots of ways to skin this cat

viewtopic.php?f=28&t=133725&hilit=door+bars

[Ol'fogasaurus]

Great post CWB, I had forgotten about that thread. One thing you also might think of is if you are going to be driving on the street they also function for side impact as the doors are not that strong. On a glass buggy it is even more of a good idea.

Lee

[Leatherneck]

Nice, good to see you back at it. Hope whatever was on your mind is gone and you can focus now. CWB is a good cage to copy and if you try just a little you will have yours done before he does too. Keep up the progress looking forward to seeing more.

[TimS]

Okay, hear me out on this one. It's kind of off the wall, but I've been trying to tackle this in my mind for a while and it fits here. I, too, have a DD baja that I want to last a long time off road, and keep me safe.

Now all the race cages, and most hobby cages transfer the loads through the sides of the roll cage. Because of this, lack of door bars is a serious structural issue, but still some folks leave them out in favor of convienience not realizing how much they've weakened their whole design. What I am trying to wrap my head around, is a way to beef up the "tunnel approach" to building a car.

With a tunnel, load is primarily carried in the center and stability is found on the outside, generally. Why could you not beef up the tunnel, with an integrated truss-type design 8 or 10" above the tunnel using the tunnel as both lower sides of a triangular truss. Load paths to the axles would be triangulated out from this main support structure, the tunnel.

What you lose out on is the torsional rigidity that a widely spaced (large diameter, if you will) truss provides. To regain the torsional rigidity, you add diagnal front and rear, but , the differnece is at the door gaps. The door gaps will still have a top and bottom tube. They will each be supported for side impact through triangulation in a horizontal plane, but that's besides the point. If your floor and roof are rigid in their respective planes, that would transfer/join the torsional rigidity of the back half with the torsional rigidity of the front half. To do this effectively, you'd need to do some triangulation at the windshield frame similar to what the TT's do, but that, I feel, would be more accepted in a daily driver than a door bar.

Is that making sense? Any thoughts? I hope this is relevant to your door bar discussion and your project overall, Volksmeister.

[Ol'fogasaurus]

This is one way to do it as far as the tunnel goes. This goes to the rear of the car but enough of the tunnel is left attacked to the torsion bar that the pan numbers are still there and don’t look like they have been transplanted illegally. This is in a glass buggy which is worse than a baja or sedan because there is no roof to spread the loads around.

In my case, a glass buggy, when I built the body lift, and did not use the ersatz ones they sell that are formed flat stock, the difference in feel, just getting into the buggy was discernible… immediately and without moving the car at all

When Buggy_Talk was still working GDRBOretired and I had several discussions on body lifts along. I asked about boxing the body lift and he said it still wouldn’t be strong enough which I now believe to be very true. I don’t think the body lift for my blue buggy is nearly as strong as the one I made for my black buggy mainly because I put a doubler over each of the kerfed bends. I think the joins between the side rails and the front and rear cross-pieces were a better option on the blue buggy.

As far as the bar between the two hoops goes, the ones like CWB and are shown in viewtopic.php?f=28&t=133725&hilit=door+bars are good options. In a lot of pro rally cars I have seen some have a hinged and pinned swing out bar which would probably be OK but t here is going to be some free space because of the pin and hinge gaps that are needed. Ideally there should be a bar going directly between the two hoops that join the upper suspension bar to the hoop to the front of the cage and the rear of the cage that should be attached to the rear torsion bar. The body lift could act as the lower bar (see below) but again, the lift is an option but it does help support the tunnel.

[quote="dustymojave”] On the heater channels...Yes and no Tim.

I prefer a bottom rail tube from the beam to the rear torsion housing.

That said... My '58 does not have a bottom rail. It has large base plates for the A pillars just ahead of the door jambs. These are curved and formed to fit the heater channels and...!GASP! welded to them...in violation of the SCORE cage rules which specify that cage members must be through-bolted where they are attached to sheet metal body structure. This would not work well where my A pillars land, as they sit on hollow structures, not on a panel which can be backed up with a matching plate on the other side of the panel.

But the above criteria depend on how the car will be used. If my Baja were a race car or were going to be used in the manner of a race car, then by all means it would have bottom rails. As a car which has often been my daily driver over the past 4 decades...It's use has been tempered with the knowledge it often needs to get me to work on Monday morning. That doesn't mean it's been babied...far from it. It HAS circumnavigated Barstow race courses and many others at...ahem..."race" speeds a number of times. But that has been 1 lap at a time, not full races. I would expect the body shell and pan to have failed from fatigue by now if it had gone full race distances each time.

Class 11 racers used to be prohibited form having any bottom rail to their cage and from having any cage work ahead of the dash. This is why Lynn Chenowth designed his Class 11 cage kit with no bottom rail and no cage work ahead of the dash. It was eventually obvious that cars could not survive that way and a primary mode of failure in those early Class 11 cars was the pan bending at the front of the A pillars. Eventually the rules were changed to allow the cage to extend from the beam to the rear torsion.

Rear torsion housings getting bent was another issue which is solved by allowing a bottom rail. My car has an under rail from the B pillar to the torsion housing. Still not as good as a bottom rail.

Side-impact crash safety is the 3rd reason for having a bottom rail. A car with a bottom rail is far stronger in a side impact, especially if there are cross members at the A and B pillars. This is far more a concern on the pavement than offroad, but a friend hit another buggy which crossed his trail and the driver of the other car died in the crash. It CAN and DOES happen.

I decided long ago (but sometime after building the cage in my '58) that the next Baja I build for myself will have full bottom rails. But I don't feel that absolutely every Baja Bug MUST have bottom rails.[/quote]

I found this very interesting; he was talking to Tim about the heater channels.

As far at tying the front beam to the cage you have seen what I plan on doing but that is not the only option on the table.

Hope some part of this helps.

Lee

[Volksmeister]

Gentlemen, thank you for the ideas and kind words (and the links, Lee. Yes, I do plan on getting a bender involved). I now have some excelent ideas for door bars! I am out of tubing and need to patronize the metal yard...

Okay, hear me out on this one. It's kind of off the wall, but I've been trying to tackle this in my mind for a while and it fits here. I, too, have a DD baja that I want to last a long time off road, and keep me safe.

Now all the race cages, and most hobby cages transfer the loads through the sides of the roll cage. Because of this, lack of door bars is a serious structural issue, but still some folks leave them out in favor of convienience not realizing how much they've weakened their whole design. What I am trying to wrap my head around, is a way to beef up the "tunnel approach" to building a car.

With a tunnel, load is primarily carried in the center and stability is found on the outside, generally. Why could you not beef up the tunnel, with an integrated truss-type design 8 or 10" above the tunnel using the tunnel as both lower sides of a triangular truss. Load paths to the axles would be triangulated out from this main support structure, the tunnel.

What you lose out on is the torsional rigidity that a widely spaced (large diameter, if you will) truss provides. To regain the torsional rigidity, you add diagnal front and rear, but , the differnece is at the door gaps. The door gaps will still have a top and bottom tube. They will each be supported for side impact through triangulation in a horizontal plane, but that's besides the point. If your floor and roof are rigid in their respective planes, that would transfer/join the torsional rigidity of the back half with the torsional rigidity of the front half. To do this effectively, you'd need to do some triangulation at the windshield frame similar to what the TT's do, but that, I feel, would be more accepted in a daily driver than a door bar.

Is that making sense? Any thoughts? I hope this is relevant to your door bar discussion and your project overall, Volksmeister.

ts39136: Yes, it is thank you. Most of that made sense. I am having a hard time wrapping my head around the details. I do plan on tying the cage into the tunnel (which in it's stock form is plenty strong in my mind to tie into without reinforcement) at various places and horizontal/diagonal bracing when possible. What I can't visualize from your description is how to triangulate the door bars like you mentioned. A sketch would help as I am a visual learner... The triangulation in the center of the windshield does look killer too! That may be getting too carried away for me at this point.

Meanwhile, I have been finishing up the front beam. I had to 'repair' the previous owner's "cut-n-turn" mess and cut my adjusters out of my old beam and weld them in. I also welded all the shock tower seams. I just realized that i didn't gusset the shock towers... Maybe I was thinking I would wait to make sure that they would not interfere with the cage tubes. I reinstalled my original torsion arms and my newly acquired wide 5 brakes. All i have is a set of bent stock wheels with nonroad-worthy tires...

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Starting to set up the steering with the old "sway bar inside the tie rod" trick. My rubber steering coupling was wasted so I tried something new... let me know what you think! I only lost about 1/4" of spline engagement. I imagine that more road vibes will be transmitted to my hands but it can't be any worse that any other kind of steering setup with out a rubber coupling, right?

-Levi

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