If you look closely on the left wishbone, in the bottom picture, towards the tyre, you will notice a seam.

I am also curious about the effect on suspension geometry. Won't the pivot point move slightly during movement? Has anyone done flex joints successfully out of steel (mentioned earlier)? As a team, we don't have much experience with carbon, but weight savings is always something that we are going for.

Also, did anyone ever answer the question of reducing tyre compliance and changing spring damping ratios? I can see a change in spring ratio from the material, but how would damping be changed?

I'm new to suspension so fell free to let me know if I'm making some really dumb assumptions.

@Composites Guy: There's no tricky piece inside the monocoque, only the front roll-hoop and the steering bulkhead to which the metal plates are mounted to. CFRP inserts in the shell of the monocoque connect them to those parts.

@rinaz: i didn't design the wishbones and our design would slap me if I tell too much but the A-arms are a hollow two-piece design. A specially designed silicon bag for the autoclave process was used to achieve the hollow design. Due to the huge geometrical moment of inertia a wall thickness of 0,8mm was achieved at a total weight of 140g for the largest wishbone.

Rinaz: Those aren't seat belt parts... we have a CNC abrasive waterjet cutter... the metal just sandwiches the glass and gives an abrasion resistant place to mount a bolt. I measured lap shear strength for the glue joints at about 2000 to 2500 lbs per one square inch (lap shear strength)... which is plenty.

To answer your question about the a-arms, we are still running the originals. When designed right composites basically don't fatigue. The only real problem we have is that some of the spherical housings (outboard end) weren't made by the most competent machinists, and a little slop around the spherical has become a lot of slop. To correct this we can (and have) machined out the spherical housing and bonded a new one in. Mostly aluminum was used for the metal bits, but ideally (for both bonding and strength) I'd use 6AL4V Ti. (The inboard tabs on the picture above are Ti).

I am also interested in how teams running flex joints are predicting their suspension's kinematics. I'm assuming you're not using off the shelf kinematics packages. Are you purely using FEA to analyze your suspension's geometry, or are you inputting FEA results into lumped parameter models? It seems to me that developing the model would be as difficult as designing the joint.

And once the car is built are you K&C testing your suspension to see if your model matches reality?

BTW: DART-CG, those are some very nice looking A-Arms. I can't wait to see your car and all of the other European cars at FSG.