John:
If I understand your logic correctly, then in order to abide by the rules I need to have a copy of every GCR since 1986, cross-reference that with every change in the last twenty-five years, and make sure I comply with every possible interpretation in all those documents?
In all the GCRs I've read (admittedly not all 25 you say I need) I don't see any language specifically allowing bolted-together bell housings in contradiction of the rules preventing stressed-skin construction. By your logic they are illegal.
I also don't see any rule specifically allowing brake balance bars, data acquisition systems, remote canister dampers, HANS devices, cockpit-adjustable anti-roll bars...shall I go on?
The tube frame is legal per the GCR, and greatly exceeds the load requirements required for "alternate" roll cage construction WITHOUT the cockpit protection panels. It meets the minimum requirements spelled out in the GCR except for the minimum bend radius on the roll hoop, but is MUCH stronger. The design has been reviewed, analyzed and approved by a registered engineer per the requirements in the GCR. I guess I didn't realize someone had given you all the drawings and specifications of the tube frame (with or without the protection panels) sufficient for you to determine its strength.
I have a PhD in mechanical engineering and have designed many highly stressed structures in the last twenty-five years, and I can tell you our chassis is much safer in any conceivable accident than any existing FC car. You may not be aware, but our cockpit safety cell is surrounded by crash protection as much as allowed by the GCR. We have a full carbon/epoxy nose that is designed specifically to absorb frontal impact, a carbon tail cone/impact attenuator, and carbon radiator inlet ducts with side impact attenuation tubes built in.
Nathan