Back home in our makeshift shop we were on a roll. We saw the makings of a stout, full-on race car-but our wives only saw a pile of scrap metal. "That's your race car?" was the incredulous response all three gave. Just like that, our spark of inspiration became a bonfire of machismo-laden determination. "That's the perfect foundation for a great race car," we said. "Just wait, you'll see."
This is the before and after....
This is the before and after. Once you start there's no going back with the rear gears, so you might as well make sure your welds are going to hold.
Ready, Set, Cut
The rearend and front suspension bolted up with almost no problems. There is still a lot of work to be done in both areas, but the first task was to cut everything expendable out of the car to get the rollcage in there. Even though the major pieces had already been removed, there were still plenty of random bolts, brake lines, and other odds and ends to get rid of. Then it was time to start cutting everything that wasn't absolutely vital.
Caution was the word of the day here. We definitely didn't want to weaken the car or make it unsafe with random cutting. We're likely to do things to the car along the way that neither nature nor any Ford engineer alive ever intended. Safety is one area where we will take no chances.
Unibody cars do not have a full ladder-type chassis but use all of the frame and body to provide rigidity. The rollcage in our race car will do that job, so we cut out everything but the floorpan, firewall (both required by the rules), framerails, and suspension mounting points. Before you get out your cutting tools, remember to cut small so you don't accidentally take out a needed bracket hidden underneath. We were lucky enough to get our hands on a plasma cutter, a wonderful tool that cuts metal cleanly and almost effortlessly with an electrical current and a stream of air. To work properly, though, the head of the cutter must touch clean metal. We also found that an electrical reciprocating saw worked well, especially where anti-vibration matting is glued down.
I'm sure anti-vibration matting is important for passenger cars, but it quickly became the bane of our little operation. Glued in place, the stuff is too well-seated to pull off, too tough to scrub off with a wire brush, clogs an abrasive disc if you try to grind it off, and releases an acrid smoke if you take a torch to it. Because a plasma cutter doesn't cut through the matting well, we took a blowtorch and a scraper to much of it before finally giving up and going with the saw.
One novel approach recommended to us to remove this evil stuff is to buy about 30 pounds of dry ice nuggets and dump them on the floorpan. After the dry ice evaporates, and chills the tar-like goo into a glass-like solid, you strike it with a hammer and it shatters into pieces that a shop-vac can remove. When we get wheels and tires on the car, we'll roll it out of the shop and try this tip. Meanwhile, we'll be writing the blue oval guys requesting that their engineers be a little more willing to put up with the occasional squeak and rattle.
Next: Installing the rollcage.
Lock'er Up
We wanted to lock the rearend of our Mustang, but a locker isn't available for Ford's 7.5-inch rear. A locked rearend applies power through both wheels; there is no differential action. The low-buck solution is to weld the spider gears together so, when we had the rearend apart for inspection, we decided to take the gears to Jim Cook Race Cars to have that done. It's actually a simple process and most racers can probably do it in their own shop.