Project Update for March 4th, 2019: Wow, what happened to 2018? It has been over a year since the last update to this project build thread, as well as many others. For me 2018 was pretty jammed up, with much of my time spent dealing with real estate issues (extending our lease, fighting a builder behind schedule on our new building construction, our shop move, our continued construction once moved in) and some staffing changes. Now that we are moved in and caught up on more important business paperwork, I have been making time on the weekends getting into the fun build coverage on some projects, like the big steps shown this time on the 1969 Camaro.
In this round we show some 2018 work completed like the rear diffuser, flat bottom undertray panels, rear wing installation, some final welding and assembly, and more. Let's get started!
UNDERTRAY WRAPPED UP
The undertray is made up of a lot of pieces that are either bonded and riveted in place or bolted in place, depending on their location and the need to access things above them. I'll zip through a few steps here quickly.
Obviously you will want to be able to access the dry sump oil pan quickly (above), so that undertray panel is removable. But these two main floor panels (below) don't have anything hidden above them that needs to be accessed quickly - just the seat and interior, which are accessible from above.
The plan was to bond then rivet these in place, so these need a LOT of hours of measuring, marking, center punching, drilling, and riveting. Since counter-sunk rivet heads would be used, to allow for a flush bottom face, every one of these rivet holes had to be countser-sunk as well.
Once all of the hundreds of tiny holes were drilled through the panels and into the chassis, the square tubing that these floors mount to was then prepped. These portions would not be visible again once the panels were bonded in place, so they needed to be protected from corrosion. A bit of work with some Scotch-Brite pads, some wax-and-grease remover clean-up, a bit of masking with paper and tape, then these tubes were painted with self-etching primer.
Now the aluminum panels themselves needed some prep work. Ryan taped off some areas then scuffed up the top surfaces of the sections to be bonded to the square tubing. This is to give those surfaces some "bite" for the epoxy to bond to. Some 2-part structural metal epoxy was applied with a mixing nozzle and the panels were ready to put in place. Ryan used an epoxy that he had used building Prototypes, which also use a bonded floor. The cross hatch pattern was one that he learned from building those cars as well.
There were some extra hands needed to get each panel in place while the epoxy was wet, and a few Clecos to hold it in place, then Ryan spent some time with the air riveter. The "spent" mandrels from hundreds of blind rivets littered the shop floor.
This picture above shows up close what the bonded and riveted center panels look like when completed. You can see the "doubler" panels that are attached to the floor panels, which secure the removable center panel underneath the driveshaft and exhaust.
REAR SECTION OF EXHAUST FINISHED
In a previous update I showed the progress on the exhaust, from the headers, through the center tunnel, the crossover and X-merge, then two MagnaFlow mufflers mounted behind the driver, just in front of the rear axle. Everything was tacked welded together, and that's where where we were before this round of work.
At the time we didn't have the rear diffuser section planned to know where the rearmost section needed to terminate. We were nearing time for the rear diffuser so the rest of the dual 3" exhaust had to be built.
I wanted additional 3" V-bands behind the mufflers, to make final adjustment easier and disassembly less of a chore. There are a lot of bends and turns tucked inside this tunnel. We all met and decided that a twin outlet in the front of the diffuser would be best, with one going to each side. Ryan built the final sections to aim at those spots.
These were left long, as the next step was the rear diffuser construction. Then, the two exhaust ends could be terminated at the plane of the diffuser.
continued below