As you’ve probably figured out from looking at some of the photos below, I’ve painted the frame. I used Jotun Penguard 2-part epoxy right over bare metal after cleaning the metal with wire brushes and acetone. It took a few days as I had to let it cure before turning it, and all four sides had to be painted in turn in order to get every spot. No magic here, just lots of elbow grease.
In my continuing effort to get everything welded onto the frame so can paint it, it’s time to build the floor pan. SCCA rules allow the floor pan to be a stressed skin, so this one fully welded around outside and to all crossmembers. To anyone who wants to learn to weld better, I recommend welding a floorpan. That’s a lot of welding. None of these pieces were laser cut– templates were made in plastic sheeting, transferred to sheet steel, and cut out with an angle grinder. Wear hearing protection. And eye protection. And lung protection. And heavy gloves up to your elbow. Angle grinders can mess you up.
The floor pan around front keel is of special interest. Some parts have a single curve which is easily fabricated, but two of the pieces have a compound curve which can’t just be bent. They have to be pounded into submission to make them fit. As this is my first attempt at metal shaping, I started out tentatively. After a lot of pounding I was getting nowhere and got angry. It turns out this is what you need to do. Pound the crap out of it, then fix the area around the big dent you just made, and eventually it takes shape. An English wheel would have been useful, but building or buying one is a big project.
There are two layers of steel under the fuel tank and the driver’s butt, one under the legs. Should be stiff, strong, and safe. And now, on to the photographs. I suffered through this. Now it’s your turn:
The firewall is a continuous, fully welded sheet of steel between the engine compartment and the cockpit. SCCA formula 1000 rules allow it to be a stressed panel, thus the continouous welding. Around the fuel tank it will be a double wall of steel for extra protection against engine explosions, insulated with shredded fiberglass to keep the fuel cool.
The fuel tank consists of an FIA FT3 certified fuel cell bladder, custom-made for this project by Aero Tec Laboratories, inside a custom made steel/aluminum container. The bottom and back of the container are made from a single laser-cut and bent sheet of steel, while the sides, front, and top are laser-cut and bent aluminum pieces. It’s carefully designed so the interior is completely smooth with all rivets and fasteners away from the fuel cell. All the rivet holes were laser cut also, meaning there’s only one way to fit it together– the correct way. This did make it very hard to install, however, as tolerances are zero to negative.
Inspecting or replacing the fuel cell bladder should be possible by drilling out all the rivets on the diagonal front panel and removing it. Not something I want to do very often.
I had not realized how many small brackets and things need to be fabricated and welded onto the frame before it can be painted. Weeks of work…
The nose mounts are so strong because the car will be lifted by a nose jack under the wing in the pits.
SCCA Formula 1000 rules require side-impact protection consisting of either kevlar laminated to the inside of the body, or 0.060″ aluminum or 18-gauge steel bolted to the frame. To keep the side impact panels from being used as a stressed member, attachment points to the frame must be more than 6″ apart. Mine are laser cut from 1.6 mm aluminum. The mounting holes were also cut by the laser to be sure of the 6″ rule, but this was a mistake as it made the mounting tabs much harder to fabricate. It would have been much easier to weld the tabs in place with holes already drilled, then drill through the tabs to the aluminum panels for exactly aligned holes. As you can see from one of the photos below, the panels fit perfectly. This project was a lot of cutting and welding with little apparent progress.
My original plan was to make the engine install from the bottom as I’d owned Porsche 911s for most of my life, but feedback on the ApexSpeed.com forum made me change my mind. The change was fairly simple, requiring only making the upper right engine-compartment frame rail removable. Taking an angle grinder to cut a big chunk out of my finished frame definitely made me measure seven times, cut once.