914 Chassis Stiffness, want input on chassis stiffness measurements Options

[Curbandgutter]

I want to check the stiffness of the 914 chassis two ways: the flexural stiffness (as in measure the shock tower movement as you lift it from the middle), and the torsional stiffness ( measuring the shock tower movement as you lift three wheels).

Then I want to input a 914 chassis into a 3d structural software that I use. I will design a tube chassis and check the flexural and torsional stifness with different tubing and thickness layouts.

Then construct the tube chassis and compare the real world results.

I want input from others as to how they would go about doing this. Or maybe give me some pointers. Or maybe someone already knows the factory stiffness?

What do you think?

[Curbandgutter]

Well after a loooong time, the final numbers are in! I ran a twist test on a 996 to compare with the 914. The 996 C4 Cabriolet has stiffness of 4,568 '#/Degree. The 914 has a stiffness of 3,326 '#/Degree. So the 996 C4 Cabriolet is 37% stiffer in torsion than the 914. Makes sense, since you'd think that the newer Porsche should be stiffer than the 914, which was built with technology of the 60's. The next step is to place the 914 on the suspension nest and start building the tube frame. I was thinking of stiffening the longs with the Engmann kit, but I'm steering away from that. I will be stiffening the "longs" with a truss system built inside of the longs. That will be the first order of work. I will twist test again at that point and see what improvement we get.