DOES THE HDK SUSPENSION K-MEMBER HANDLE BETTER THAN A T-BAR SUSPENSION?

J-c-c said

I didn't read anybody mention this K member solution, and I have toyed with it, because it has some really tough hurdles, but it ought to doable especially with a non TB IFS, is an OEM style carbon fiber mopar K member. It would check a lot of boxes.

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I'd sooner use die cast aluminum like many contemporary cars appear to. There are several processes which can mimic die cast results without the expensive tooling.

CF comes with many challenges. For a dedicated racer it might make sense, but for the typical cruiser or drag car most folks build it would be wasted effort IMO. Adding hardware attachment points to composites is an engineering exercise in itself, let alone preventing corrosion where CF and other metals meet. Designing for the proper load paths and developing a reasonable NDT program would probably require building more test parts than the number of retail units that would sell. Using chopped CF or trying to get a homogeneous CF mix winds up giving up a ton of the benefits but doesn't typically cut down much on cost. Heat resistance is limited by the resin/epoxy used as a binder too. Metals don't have that issue near as much.

Seam welding and lightening up a stock K is something most guys could do and doesn't take a doctorate in composite analysis to do well. Besides, the main benefit of CF is the higher modulus than steel, not necessarily it's strength. The higher modulus means the part can be lighter for the same stiffness, if done right. But a stock k is not optimized to begin with, though welding can quickly maximize what's available. Going aluminum could save some weight, but the modulus is lower and so stiffness gains would rely on increased section thickness. The end result does tend to still be lighter, but design choices still need to be made.

In the end, a CF k member might be a bit lighter and maybe stiffer but it would have several significant drawbacks and cost would be quite high. The real question though is whether the K is even a significant contributor to chassis flex. A super stiff K is kind of a waste if the front frame horns are still squirming about..