Test fitting the diff back in the car to ensure everything will fit prior to welding in the strenthening plates. Also some more minor gusseting on the frame and A-arms. And the really big news is some of the electronics (ECU, fuse box, relays) are going in. Big, productive week!
I'm using a Torsen LSD-type diff out of a second-generation (NB) Miata. These are pretty stout little rear ends, but they have a known (i.e., "it's a feature, not a bug") weakness, whereby the big mounting arms (or "ears," as they're also known) break under big torque-transfer situations. This problem is exacerbated by removing the rubber bushings at the end of the arms and welding in solid plugs (like've I've done for some long-forgotten reason....).
Anyway, the solution to this "feature" is to weld in strengthening plates on the arms. Here are a couple of the alumnimun plates being test-fitted prior to welding-in.
The rear underside frame strengthening and wheel tubs are finally done. Much bigger job than I thought it was going to be. The rear.... uh, electronics "cubby" firewall thing is also welded in, followed by a shot of primer on everything. There's still a few minor tweaks to do, plus I want to strengthen the mounting arms on the Miata diff before we put that back in, but otherwise, the rear end is basically ready to be reassembled. The car could then be taken off the rotisserie, but we're thinking of leaving it on for a bit just to make some of the hydraulics and wiring installation a little easier. Dunno. For now, however, I'm really happy with how it's turning out...
We got the last of the tubbing work done. It still needs some sanding, followed by paint.
