Jr dragster chassis

[samotorsport]

Hey guys , my name is Sam , i m 42 , from Luxembourg Europe .
I am currently building a new jr dragster chassis for my son.
We bought a car couple of years back and raced it for 2 years.
This year we decided to give it a major overhaul which ended on finding some bad mods covered under paint.
Therefore i decided to build a complete new car, CrMo instead of mild steel.
Here are the first pics .
Updates will follow .
But to start with , I also have a question.
Does the orientation on the tube joints matter ?
I mean from the cell to the front half . The 45 degrees , beeing the long part on top or bottom.
Thanks in advance
Greets
Sam

[samotorsport]

First pictures of the build

[slingshot383]

Long end of the 45 on bottom when sliding smaller tube into larger tube. When doing diagonals, use a 1/4" shim to keep them off the main rails and just on the uprights (also to get a full 360* weld on the tube.

[samotorsport]

Thanks a lot , I plan on doing the diagonals this afternoon . So just in time thanks a lot .
Is there a particular reason to have the longer part in the bottom?
I have seen chassis with all 4 in the bottom like i planned to do . But also some chassis where the lower ones where with the bottom ones long , and the upper rails where inverted so the longer bit was on the top parts.
Thanks
Sam

[THE FRENCHTOWN FLYER]

Thanks a lot , I plan on doing the diagonals this afternoon . So just in time thanks a lot .
Is there a particular reason to have the longer part in the bottom?
I have seen chassis with all 4 in the bottom like i planned to do . But also some chassis where the lower ones where with the bottom ones long , and the upper rails where inverted so the longer bit was on the top parts.
Thanks
Sam

I think it may have to do with the bending moment put on the frame rails. If the frame wants to buckle in its middle from bending (visualize bouncing down from a big wheelie) then the bottom side of the bottom member will be in tension and the load can be distributed over the larger section of the 45 degree bend. Likewise the top side of the top member will see the biggest compression load and then the top of the top rail would be the most highly stressed and hence would benefit from the top side being longer.

[samotorsport]

Thanks a lot , yes this makes sense
So on the jr not that important , but still , lets make it correct right away
Thanks

[samotorsport]

Current state

[wideopen231]

Looks good. building yourself should save some cash and be better piece to boot. CM over mild steel is no brainer.Any weight shaved with smal motor is huge.

[samotorsport]

Thank you ! I will update this regular .
Next step , welding closed the remaining cell , then additional bars to the rollcage .
After that , front half . But this is only going to happen „next year“