side impact | LudemannEngineering

Fully paneled cockpit

While the sides of the cockpit already have side-intrusion panels on the outside, they will also have a second panel on the inside to prevent the seat foam from extruding between the frame tubes and pushing on the outside panels, something those outside panels aren’t equipped to properly resist. The interior panels also must follow the SCCA rule against stressed skins that requires chassis attachment points to be more than 6 inches apart. Due to their different shape and size, the interior panels have a completely different mounting pattern and can’t share any of the exterior panel mount points. Thus, many more tabs are cut and welded on.

The seat back is formed by the fuel tank and three additional pieces of aluminum, shaped at the sides to provide shoulder support on the front while providing space and access at the back to the fuel pump on one side and the fuel filler on the other. The center section is removable to access the shoulder harness mounting points.

: Test fitting the right side cockpit panel, view from inside

: Left side clamped in place

: Separate mounting tabs for interior panels

: Left side mounting tabs welded in place

: Left side cockpit panel installed

: Test fitting the seatback

: Seat back panel had to be cut in 3 pieces; right piece shoulder panel shown

: Left shoulder panel provides access to fuel filler

: Seat back center panel with shoulder harness cutouts

Aluminum side impact panels finished and mounted

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.