Thanks to Jeroen's thread I decided to cut away the body seam sealer and have a look at how the shock towers are fastened (not fastened?) to the body.Brad & Jeroen I can see how they would tear away after a while with stiff springs and racing stresses. Here are a couple of pics..........

Thanks for the tip!!!!!

SteveSr

Hey Steve,

Looks good.
Can you post some pics looking from the opposite direction (I'd like to see where you welded that lower xbar)

cheers,

Jeroen

Here ya go Jeroen,I fashioned a piece of sheet metal into a "U" shape and over the exposed end of the double walled brace between the shock towers and then tied it in with tube.
My thought on the towers themselves was to stitch a bead all the way around the seams then in a gussett like you did.......
Whata ya think???

SteveSr

Whoops.......forgot to post the pictures..................

and another......................

Steve,

I hate to be a critic, but I think you need to take another look at this pic



(or the other pics in this thread)

You need to cut out the last piece of firewall (marked in red in the pic below).
The part you left is what hides the crappy connection between the frame rails and the shock tower...

Also check for engine clearance on that lower x-bar. The stock firewall is higher in the center
(may not be a problem, but better check twice now )

cheers,

Jeroen

Could even more of that shock tower come off? Like the part in red, or even the green? Doesn't the x-member only need to tie the tops of the shocks together and just a little is needed for supporting the tranny?

Yep, more could be removed
But if think the shock tower is double wall and it'll be a bitch to weld it up nicely again...

at least the portion in red could come off,it doesn't really do anything now that the trunk floor is gone. Thanks Jeroen for pointing out Iwas looking at the wrong side of the shock tower The tube I welded in across there doesn't interfer with the engine at all. But now I have to re-think the whole thing

SteveSr

Cut it out... you'll be shocked (no pun intended) what you'll find...



Just the top bar should be strong enough
"thinking" is about half the time I spend on this car
Got lots 'o stoopid ideas and then trying to figure out what would really work
Looking at what others did sure helps a lot to get you in the right direction
My theories seem to make sense (to me at least ) but only time will tell if they really work

cheers,

Jeroen

Thinking too much is my problem I,m a toolmaker by trade and tend to over engineer things when I building something!!!!

SteveSr

And now, for some unsolicited advice:

A problem the offroad guys found out is that if you weld tube onto another surface (even cromo), it will crack near the weld and eventually punch a hole through the material. It seems doubly the case for heavy tube into sheetmetal.

The drawing is very poor, but I would cut away a large piece of the crossmember bar (in green) so that both ends match the back/top contour of the shock tower (in red). This increases the welded surface area (blue), and decreases the amount work that is done against a specific piece of sheetmetal.

What about a piece of sheet metal on the end of the tube first then weld to the body????

SteveSr

Yes, that works. You want the piece to be larger to distribute the load. However, in your specfic instance, the tower appears to be double walled, so if the weld hasn't penetrated to the 2nd wall, your work is done.

I threw in the drawing because I like how the top of the tower has lots of shape and surface area, which gives strenth, and is closer to the actual stress point of the shock mount.

Here's what I did on my previous chassis
The x-bar is as high up between the shoch mounts as I could get it
The shocktower has a nice curve, which adds strength to the original surface and also makes for a bigger surface to weld to

pic 1

way up there

pic 2

close up of the curve

pic 3

Here's the rest of the x-braces
The ones from the shock tower to the tranny mount are at a pretty sharp angle, so the impact this bar would create on the surface would be way less compared to e.g. a 90 deg. angle
And there's quite a big contact patch because of the angle too, so I didn't use scab plates here either

pic 4

I dove into the hellhole last nite with in hand,air chisel and grinder and after about an hour and a half here's what I found..........the shock towers not welded to the frame rail!!!! What was the factory thinking

one more................

I told you you'd be surprised
Glad you took it out huh?

Yes! very surprised. Now on to the other side

SteveSr

Welded up one side lastnite ,now to the other side.........

SteveSr

Perhaps Chris or one of the other expert welders will chime in...

I'm certainly not an expert. But I've always understood that over-heating a weld joint will make the metal brittle and more prone to cracking....

Thus, you may want to stitch weld when you do the 2nd side.

brant

I'm a toolmaker,certainly not an expert welder, any advice would be helpful.
All though I have been told that there is not enough carbon in mild steel to harden the metal surrounding the weld.

SteveSr

Steve and Jeroen,

Thanks for the photos and explanations. I think I might finally understand the weak point you and Brad have been talking about for so long.

I don't know if I'm going to strip and reweld my street car though!