Unfair Rear suspension and Spohn’s Del-Spheres

When Art Morrison first approached us with the idea of the transforming / combination 3 and 4 link rear suspension, we loved the idea. And after I thought about it a bit longer, I called Matt Jones (their suspension engineer) at Morrison and told him to be sure and design the brackets of the new suspension to use Del-Spheres. Matt took some measurements and they were able to accommodate us.

As a result, Steve Spohn’s Del-Spheres are all over the rear suspension on Project Unfair, and for good reason. I first used Del-Spheres on my previous project (II Much) when the original rod ends started to wear (after a few hundred miles) and started to transmit NVH (noise, vibration, and harshness) into the car. I swapped the rod-ends to Del-Spheres and it greatly reduced the NVH, with no loss of accuracy or articulation.

Strictly speaking, the Del-Spheres don’t have quite as much misalignment capability as a rod-end, but for rear suspension linkage arms like Unfair’s combination 3 / 4 link, it offers plenty with no loss of strength. The main body of the Del-Sphere is forged steel, with a forged ball. The body and ball are separated by Delrin rings, and the body incorporates a rebuildable and grease-able design that allows for the quiet of rubber and the accuracy of steel.

We’re confident the car will have excellent handling and ride characteristics, as well as handle the 1200 hp the engine will put when we put the hammer down!

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Here’s the whole rear suspension in what Frank and I call “5-link” mode. 🙂 Note how the Del-Spheres are used on all the control arms except the Watts link.

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This is the road racing setup with a 3 link. For drag racing, the upper control arm in the middle is removed and replaced with two control arms on the side. The Del-Spheres provide the misalignment we need for turning the car on the 3 link setup, and the strength for 1200 hp launches on the 4 link setup.

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Here’s a closeup of the Del-Sphere, screwed into one of Unfair’s 4 link upper control arms.

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Taking off the pre-load adjuster shows the Delrin inserts and how they isolate the ball from housing.

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Here’s a complete disassembly. The forging line in the housing is visible.

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