2/28/11
Having worried for a long time about this car’s structural integrity and mine and my passenger's survivability in the event of a crash, I recently undertook to tackle the corrosion in the unibody. I knew there was rust here and there, bubbling up the paint and making holes in the wheel wells, but I wasn’t sure how extensive it was. What I discovered when I peeled away the passenger side inner rocker panels – by hand! – was that things where a little worse than I imagined. Having little experience with rust repair techniques, I cleaned things up as well as I could and decided to keep my car dry and drive gently as I did my research and hatched a plan.
Having worried for a long time about this car’s structural integrity and mine and my passenger's survivability in the event of a crash, I recently undertook to tackle the corrosion in the unibody. I knew there was rust here and there, bubbling up the paint and making holes in the wheel wells, but I wasn’t sure how extensive it was. What I discovered when I peeled away the passenger side inner rocker panels – by hand! – was that things where a little worse than I imagined. Having little experience with rust repair techniques, I cleaned things up as well as I could and decided to keep my car dry and drive gently as I did my research and hatched a plan.
Beyond merely fixing the rust, I was interested in increasing the strength of the chassis, as well as improving the stiffness. I had seen pictures of crashed Mustangs and Falcons and had pbserved that the passenger compartment almost always collapsed in strong collisions. Often the seats also tore free of the floor pan. Coupled with the spear-of-death steering column in these cars the prognosis was dire. More so when you consider that my car is a convertible so it lacks the extra support of a roof. It got to the point that I didn’t want to have my family in the car anymore. I wondered: was there a way to reinforce the passenger compartment as I did this rust repair?
As I studied chassis and roll cage designs I hit upon a great idea. What if instead of patching the rocker panels I replaced them with 2x4x.120 mild steel tubing? The fit was perfect! I set to stripping the car down. Last time I started on the passenger side, so I had much of that already cleaned up. This time I decided to see how the driver’s side was, and I discovered that it was much worse. By the time I was done with two-week’s worth of cutting and grinding the floors where gone as was much of the torque box in front, the box that the rear spring ties into, and parts of the rear fender and wheel well. I had developed by now a much finer appreciation of the structure of the car and my plan evolved. What had started as a rocker panel replacement was now becoming the construction of a perimeter frame. With the front and rear torque boxes largely gone I could tie my “rocker” tube into the front and rear sub-frames, and this new structure was the perfect foundation for a roll bar.
Here is a video outline of my plan:
6/30/03
Chassis, Part 1
So far the only thing I've done is add a "belly bar " while I was doing the suspension rebuild. It ties the lower suspension points together. Did it help? Well, the car feels more solid. Since I rebuilt the suspension at the same time it's hard to tell how much is the brace and how much is everything else. Nevertheless, I couldn't imagine designing a convertible or any kind of performance car without a brace between the left and right lower suspension. Only $35 on Fordsix.com plus some paint.
Later I added a "Monte Carlo" bar that ties the upper shock tower together. I now consider this an essential modification as it made a huge difference in steering response as well as noticeably reducing NVH and cowl shake.
Chassis, Part 1
So far the only thing I've done is add a "belly bar " while I was doing the suspension rebuild. It ties the lower suspension points together. Did it help? Well, the car feels more solid. Since I rebuilt the suspension at the same time it's hard to tell how much is the brace and how much is everything else. Nevertheless, I couldn't imagine designing a convertible or any kind of performance car without a brace between the left and right lower suspension. Only $35 on Fordsix.com plus some paint.
Later I added a "Monte Carlo" bar that ties the upper shock tower together. I now consider this an essential modification as it made a huge difference in steering response as well as noticeably reducing NVH and cowl shake.
