Some progress on the chassis and monocoque while on vacation. I have been working on the rear sub-frame and how the loads will be distributed into the chassis. So far I’ve been able to utilize extrusions that are easily sourced. This will help make sure supply is always available, and the cost is kept as low as possible.
The 6063 aluminum extrusions will be stitch, spot, or seam welded, however, the roll cage will be removable, as will the front and rear sub-frames. I’m trying to achieve a rear section that could be assembled and then bolted up to the chassis which could make assembly and servicing much easier.
Weight and stiffness are the main concerns, but the choice of a welded sub-frame over a riveted structure is for service requirements. A riveted and bonded chassis that saw daily use could need major servicing in just a few years. The vibration of driving on common roads, as well as the V8 engine would loosen the joints over time and would require re-doing the rivets and some bonding. Messy, expensive, and time consuming.
So far total weight of the chassis as pictured is around 407lbs, but with the weld fillets, and various hardware, closer to 450lbs. My current benchmark is the Lamborghini Aventador chassis which is 505lbs and gets 1mm of deflection from 35,000nm of torque.