Earl: You always have to deal with a cg. Mine keeps getting lower. All I have to do is eat more and excercise less.
rdorman: ERA's use front steer, i.e., the steering rack is forward of the front-wheel centerline. As for changing Ackerman, you shim the steering gear forward or rearward. As for more Ackerman, you don't want it; you want less. It was designed in the olden days, like for hay wagons, before chassis engineers realized that tires developed slip angles while cornering, which requires steering to be more parallel. Full parallel means the front wheels would steer at the same angle. Ackerman is where the inside wheel turns at a greater angle than the outside one, which works fine for forklift trucks, but not perfomance cars.
How do you change Ackerman/parallel steering? By moving the inner or outer tie rods end forward or backward in a level plane. This is best done by relocating the rack. Moving it forward moves the steering toward a more parallel condition and vice versa.
Tires? I like the Yokahama 235 front and 295 rear 15's, although they are radials. As for camber curves, bias-ply tires require less camber change for cornering. Also, the wider the tire, the less camber change is required. As for exactly what the camber curve should look like, I don't know because this would require extensive testing which I haven't done with the tires and the Cobra.
Need: Any lighter component that replaces a heavier one above the cg will lower the cg. Aluminum heads and manifolds accomplish this. And, you bet, more weight on the front tires will induce understeer if nothing else is changed. Add in some more rear bar will move it back toward oversteer. It's all about making the tires work harder or less hard. And there are transients to consider, also. The subject of vehicle dynamics is quite involved, but it's all about the front to rear tire slip angles--more in the front is understeer and more in the rear is oversteer. When front/rear slip angles are the same, handling is neutral. Simple!
I hope this answers your questions, but such answers typically generate more questions.
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