I'm mounting a kirkey road race intermediate seat into my Miata,it'll be fixed mount to the floor and I need to come up with a safe way to brace the back.For sure no tube pointing at my back kinda stuff.
I'm thinking something like a horizontal strip of 1/8" or 3/16" think aluminum bent to conform to the shape of the seat and bolted to tabs on the harness bar.
If that's acceptable should the arms back to harness bar angled outward to brace a side impact and probably distort somewhat in a rear impact in an attempt to absorb some of the force??.
Tube pointing straight at your back welded to a steel plate shaped like the contour of the back of your seat and then thru bolted to the seat. Thats the way we do it. If a roll cage foot won't blow thru a floor plate when the car flips up into the air and lands on the roof, the tube on the back of your seat isn't going to either. I like to use a 1.5" tube and then weld on a 1.75" piece of tube with a slit in it and a bolt on it. Slid the 1.5 inside the 1.75 and tighten. Allows for adjustments of the seat. You are suppose to have a horizontal in the roll cage, so I always put them right below where I need to seat back support to be. I O Port and others make nice one's. Take a look at whats commercially available and emulate.
Yeah. I've never understood which part of physics class the anti-backbrace people missed. If you back into something hard enough to drive a 1" tube through a 3x5 inch piece of 1/8" steel, and then through a 1/8 inch piece of aluminum, then through your spine, you have a whole lot bigger trouble coming on.
In reply to Streetwiseguy:
Psst: I'll let you in on a a little secret; most people aren't very smart, especially racers. Ask any tech inspector and they'll tell you some of the horror stories they've seen.
Point taken Streetwiseguy.
I think Stefan is saying I'm not very bright.
In reply to kevlarcorolla:
Not so much. There is a very common school of thought, mostly among road racers, that a back brace is death, and FIA seats are designed to not require them. You presumed these thoughts were true.
I say, Who built the floor of the Civic the FIA seat is bolted to, and how many years ago? Back that Civic into a wall, and how much leverage is generated against those two little 8mm bolts? Pull those suckers out of the floor, the belts are now useless, and you are flopping.
Their typical response has to do with engineers, and the FIA, and a bunch of French rulesmakers. Well, I watch stock car racing on tv. Those berkeleyers hit the wall at 200mph, barrel roll down the front straight, and climb out of the aluminum seat in their car with enough energy to throw their helmet at the guy who hit them.
Good enough for me.
So I just did this.
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Works great but its non adjustable. You had better really like that driving position.
How I had mine, I/O Port adjustable ones:
Also have IO port pieces. They're thin(thinner) wall aluminium tubes, which is far better then a rigid steel tube with gussets as the above poster designed, and also have a shear pin. You're overthinking it by gusseting the backbrace - it's not supposed to be super strong, it should be the same strength relatively as the seat. You just made a steel impaler.
One guys says make it bullet proof the next says make it fold with the seat,you'd think this was the internet or something.
Putting a big guy in a little car means the seat isn't going to work in many locations,I put this where I like it so its all good.
