I build roll cages

[ForcedFirebird]

When welding to the floor last, I wiggle the structure around in the car. I've even used ratchet straps to pull it in far enough to weld, then spread it back. Really depends on the car - e30's are cake (partially just from repetition, and they are very square), but some of the FIA stuff I've done in little cars were head scratchers.

[Mike36]

Oh sweet yeah, thank you. Those will be featured later. Btw, since usernames can differ between platforms, did you see the cages on my Instagram? What's your handle there, is it twinzmike?

Schwrzy_e30

Do the owners of these roll cages leave them raw or do they have to get painted after all the welding is done?

[Chilezen]

When welding to the floor last, I wiggle the structure around in the car. I've even used ratchet straps to pull it in far enough to weld, then spread it back. Really depends on the car - e30's are cake (partially just from repetition, and they are very square), but some of the FIA stuff I've done in little cars were head scratchers.

Nice, I too have had to pull together bars like that. I'm curious to hear about those more challenging cars, what cars and what bar configurations were the most memorable?

Schwrzy_e30

Do the owners of these roll cages leave them raw or do they have to get painted after all the welding is done?

I remember your vert with the red interior from a drive we did years ago. I think we met at a 7-11 in the beginning.

We recommend everyone to paint the cage as soon as possible, because the bare metal will rust somewhat quickly. Some are "lazy" or too busy to paint it, so they just leave it.. which is such a shame; a good cage adds value to the car, but that same cage all rusted really makes the car and cage look like shit. Some guys will say they like the raw look, and will clear coat the bars. I think that's silly, go paint the cage. I'm proud of most of my welds (lol) but I'd rather the whole ensemble be coated evenly with something that really compliments the car.

There was one cage we built, mostly, but removed the bars in large sections after welded certain ones together. Then we sent them out to be powdercoated. Then we finished welding the rest of the joints once it was back in the car, and sprayed a gloss black on that. Overall it was more trouble that it was worth in my opinion.

The right think to do is to take the car to a paint shop right after welding the cage, removing the windows and whatever you can, and having a professional paint it.
At the bare minimum, cover what you can and take a spray can to it.

You just paid a chunk of change for this integral part of your car--now go protect your investment!

[Chilezen]

More M2 pics

[Chilezen]

And more M2 pics

[Chilezen]

I'm noticing I just took more pics of the M2 than I did of the E30. Whatever

[OSAH racing]

Those welds are Cherry!

[Chilezen]

Thank you!

I've got another cage to post. 'Merica this time.

[Chilezen]

I'm posting 2 nearly identical photos of this because I put a lot of effort into the fit & finish of the panels around the cage.... as well as the cage going around the panels & dash.





For the most part, in nearly every cage, I think a dashboard can and should be retained within a cage. Usually it is extra weight that you don't need, but if you're not psycho crazy about it, the factory dash will really tie the car together. Sadly, most cars/builders will hack up the dash because they don't have the time to care and make it nicely integrated. Once in a while, though, somebody lets me do my work and goodness results.

Oh, and the panels are easily removable, so the cage can be painted easily there. The entire dash, however, is now permanent, it cannot be moved/removed at all. Still totally worth it.

[Chilezen]

Very installer-friendly bar setup here.



Bars are clearly labeled and easy to weld around. No excuses for bad welds!







The rear bars may look like they were placed in the "most convenient" spot, but I chose there because they're directly above the "frame rails" in this car. Yes I know a unibody doesn't have a frame, but I mean more like there's a channel of reinforcement here that ties to the suspension/subframe. I do like to make strong boxes to tie together structural areas, but this time, the easiest spot made the most sense!

[Chilezen]

And it continues





Don't you love it when it's easy to get in and out of your racecar?

Nice and roomy in there.





And once again, being mindful of the door bar design to not create an "S" bend here, but to carefully build all the bars to maintain their maximum amount of strength.




I'm sure you've seen how small the window is on these "tanks". But at least the cage doesn't make the problem worse in any way. Better we keep the bars up and out of the way, so the frame around the window is strong, so you can still get out if the door doesn't open!

[Digitalwave]

This is an awesome thread. You are very talented, and I appreciate your ability (and willingness) to share about your craft and the process behind it. The photos are very good, as well.

I noticed that you advocate for "NASCAR-style" door bars on page one, but also did bent-X (FIA-style) bars on the M2. What are your thoughts between the two?

I'm a bit of a nerd about the details of roll cages, more out of curiosity than anything, since I am not an engineer or a fabricator. It seems to me that NASCAR-style door bars have fallen out of favor, instead going back to simple X-bars (for large cars with ample space for the driver) or more often, bent-X FIA-style bars. NASCAR bars are often done quite poorly. They can be too low, insufficiently braced, or worse, S-bends are quite common. I often see NASCAR bars with two S-bends (each end). I can't understand how that ever passes tech inspection.

In any design, I like to see the extra A-pillar support bars that you added, as well as intrusion bars as you mentioned. They add strength, and typically don't affect ingress or egress.

Keep up the great work and thanks for sharing.

[Chilezen]

Keep up the great work and thanks for sharing.

Thank you!

The reason for building the bent-X style door bars has more to do with the decision made by the customer. I'll start by saying, I do not speak with the customers, because I am the fabricator, not the business owner. Also, sometimes (as was in the case with that car) we were given the car by another shop who built up the rest of the car, so, our communication was between that shop, who then delegates info to the car's owner.

Typically, the reason for building X door bars comes down to the desire to keep the windows functional, so that they can roll them up and park the car "safely" I guess. Some others will argue for the slight weight savings by having less bars than the Nascar style. Also, for those penny-pinchers, the X style is going to be cheaper, using less material and being easier to install. There might be another reason I'm missing, but overall, I think it comes down to the cost and negated level of safety they desire. After all, the X style is still safe combined with the safety of the cage, so to them, they may not want to justify the "extra" value there is.

There isn't a wrong choice if either is done correctly.
But if the famed Nascar style is done incorrectly, a good set of X styles are the better choice.

I see why S-bends are chosen, for the logical configuration to make bars fit, but that's only a consequence of designing the rest of the cage poorly. S-bends can be avoided with better placement of the Main Hoop relative to the car's B-pillar, and, with a better angle of protrusion for the Nascar bars. I have built hundreds of cages, and never have I had to sacrifice the design using S-bends.

I don't know that Nascar bars have fallen out of favor, as compared to, not that many people are willing to build them correctly.

The extra A-pillar supports (FIA bars, I assume we're on the same page, I've heard them be called a few names) are a standard feature on our cages. At the first shop I worked at, they were generally only added to rally-oriented builds. Which makes sense there, of course, but weren't a staple among the track builds. I'm glad now that every car gets them. It can be a little inconvenient when those bars interfere with the dash, but hey, a stronger cage ought to be worth it.

As for tech, BOY have I seen some GARBAGE cages out there. I have cut out a few garbage cages as well. I don't know what high quality blindfolds the builders, customers, or techs had been wearing, but for some of these cars to have made it that far onto a track, is beyond me. I can't believe some of those morons get paid more than me, too.

Intrusion bars aren't as common as they should be, but they're such a nuisance to install. Especially with newer cars, a ton of wiring is stuffed into the front there, so it's risky to make a permanent obstacle in that area. I don't know what all those wires do, maybe they'll need to get to them later? If I pull them all to the side, will they be permanently in the way? Is there a sufficient amount of space to land a plate and a bar to this cramped area? How much more time and cost are we willing to put in and pass on to the customer for these? Most of the time, all of these factors are enough of an obstacle to prevent the design from being produced. I would say, the older the car, the more likely you'll see them. That also has a lot to do with newer cars being stronger and older cars... needing extra strength down there.



Say you're driving through a sweeping turn at speed. You run wide and kick up some dust. You lose the tail, you counter steer, can't grab it, and you're out of control but you're still on the track. the guy behind you can't see you in the cloud of dust, but, you must have gone off, right? That's why there's all the dust, right? He's looking but doesn't see you until his bumper is on your door.

So tell me, 1 in a million chance that happens. It happens. At that moment, you aren't going to remember how much more the Nascar bars cost... but you will know the difference they made when you're about to get T-boned.

Idk, if the little extra protection is available in such a dangerous activity, why wouldn't you opt for it?

[moatilliatta]

A whole another thread could be written on this.

The x bar is in tension and the “nascar” bars with most likely a s-bend are in compression on side impact. I’d take a good FIA spec X bar, triangles ftw.

I’m skinny and flexible, ingress and degrees isn’t a problem.

Thanks for sharing your work, I’ll continue to peak in here :)

Digitalwave You're building an M2?

[Chilezen]

I respect both options, and as stated,

There isn't a wrong choice if either is done correctly.

9 times out of 10, a fat guy will opt for the Nascar bars lol.


If you crash at 150+ mph, depending on the type of crash, the configuration of the cage may not be as important as the quality of the welds... where a great-designed cage could snap at poor joints. And other factors will play into the survival of the occupant. Suppose it's a lower-speed crash but the harness is not unlocking, the car's engulfed in flames and the fire system pull tab failed. Suppose the seat bracket failed. Maybe not the bracket, but where the bracket bolts to the floor could have stretched upon impact. Scary things can happen.