I got started one the chassis rails today, just one side as I will probably need to move the car away from the wall to get proper access to the other side.
I put a fair bit of thought into how I was going to cut them, I wanted to keep it reasonably neat but still remove as much sheet metal as possible under the WTAC rules.
So this is what they looked like before I started.
I only had a couple of angle grinders and a reciprocating saw to work with. I guess a plasma cutter would be handy but I don't know as I've never used one. So I cut a straight line behind the base plate of the main roll cage hoop being careful not to cut into the outer wheel arch.
It came out pretty good after I used a flap disc to even out some of the cuts.
I then decided to remove that lower pair of captive nuts and extra bracing on the bottom edge to shave a little extra weight. There was about 6 spot welds to drill out.
After some cardboard aided design (CAD) I had a plate cut out ready to box off the rail.
I TIG welded the top edge where it buts up to the base plate of the roll cage and then converted my multi-process welder over to MIG to do the rest. My MIG skills are still pretty average but welding to the chassis with TIG is almost impossible because you can't get it clean enough.
This is the job finished, I'm very happy with how neat it turned out.
Next job I'll cut and notch some tube to join the suspension cradle to the chassis rail and then repeat it all on the other side.
Next weekend I'm going to WTAC so probably won't be able to work on the car. Looking forward to checking out some time attack machines though, especially the HKS TRB-03.
