Tube opinions

[heist]

I'm new to all of this and want to make some braces for my trunk, but really having trouble picking the correct tube. Looking for some opinions on tube type (CDS, HFS, DOM, ERW) and O.D. / thickness for my application. I know a few members have fabed up some stuff and would appreciate your recommendations. Here's a quick diagram of what I'm trying to achieve.

I don't have a pipe bender and will be using a basic mig welder.

[Guest]

Just get ERW, it's cheap and it'll work fine for your application. It's around 1/5th the price of DOM. If I were doing it I'd probably use 1.5-1.75" 0.125 tubing, but not in the way your diagram is. You've got your bracing backwards, those 45 degree bars should connect right at the top of the coilover. Even then, I'd probably do some boxed structure on each tower..ah fck it, here's an MS paint picture.

I'd use 1.5" 0.125 square stock and weld it to the floor/up the side of the shock tower. A single bar across will suffice, especially if it's 0.125, that bar could be even thinner like 0.083 or something. Overkill is the best kill.

[c.d.iesel]

you need to read a book about race car frame/suspension

design to understand the direction of force/stress

[OopsClunkThud]

you need to read a book about race car frame/suspension

design to understand the direction of force/stress

agreed!

with this design you'd be applying a force sideways across the beam so you'd either have to make it massive or it would bend. Think of straws, how much force can they take just pressing on the ends vs applying a force in the middle?

[heist]

In reference to my basic design I was going to keep the orginal shock tower and hook it into the bar to hold it in place, not as a structural piece. The bar would have a very small amount of stress from the shock. Right now its just a small nut and rubber spacer holding it in place. The bar is to keep each side from flexing and popping out the rear window. Thanks for the comments and info manimal.

[TobyB]

I'd use DOM, for only 1 reason-

If this car ever went racing, the ERW would fail tech.

It would be construed as part of the roll cage, even though

it's not, really.

Yeah, it's a long shot, but for the extra $75 or so in metal,

it'd never come up...

That's my opinion.

I'm stickin' to it!

heh

t