"If you are realy interested in getting good information ask for a copy of the deflection test report from the chassis builder, anything other than this is usless information in my humble opinion"
I've been working in auto fabrication for about 30 years. I designed and built my first chassis from scratch in 1988.
Using Autocad and Inventor I designed a GT40 chassis loosely based on a combination of the KVA chassis and a MK V. Then spent about 2 weeks building an 1/8 scale wood model solely for the purpose of improving and refining the torsional rigidity.
I've spent 4 years so far building this chassis from scratch including uprights machined from 7075 billet on a small mill drill (no CNC), and scratch built stainless headers.
The ONLY parts I'm not doing are the axles and the flywheel. Everything else, all the designing, machining, fabricating, cutting, grinding, sanding, welding, riveting, bonding, bending, shaping etc I've done by myself.
I spent about 3 weeks refining my torsional rigidity test method. I've performed about 4 tests now during various stages of construction in order to monitor progress.
On a scale of difficulty of 1 to 10, compared to designing and machining uprights from scratch, I would say performing a torsional rigidity test is about a 1 or 2.
But you know something? After 30 years I just don't have confidence in myself anymore. I don't think this is "good information", in fact I think it's "useless information". I'm going to search out one of these "chassis builders" and find out who's doing their rigidity tests because obviously they are the ONLY people on the planet who are competent to perform this horrifically complex, difficult and costly "rocket science" procedure.
IMHO