There was a time when your suspension improvements would involve things such as improving your tires by finding ones that provide more grip and then improving their performance with better springs and shocks and/or struts. Then you would see a good alignment tech and see what adjustments were possible.
Then there would be more aggressive sway bars (anti-roll bars). Perhaps you would opt for a set of quality coil-overs that would allow ride height adjustments and corner balancing.
Now, even more dramatic suspension options are available:
Verkline of Germany has many suspension improvements that include engineered sub-frames to go along with components that provide improved dynamics and adjustability:
These kits reduce weight while providing increased rigidity and adjustability.
AJE produces complete frames for various trucks along with the chassis components to modernize the handling capabilities.
SPC has a wall of products that provide more suspension adjustment than the factory may have provided.
The typical unibody designs need to have bracing added in key areas to provide the suspension with ridged predictability.
BMR has kits that provide better suspension dynamics than factory.
Above is a front suspension with its own sub-frame and adjustability for minimizing bump steer.
Same for this strut font end.
UMI is another solution provider.
Above is a rear frame that allows for the addition of a Watts linkage to this solid rear axle.
Cortex is another suspension upgrade specialist that has managed to engineer some amazing suspension modifications that seemed impossible to accomplish.
For instance this rear end kit that adds a meaningful Watts linkage to a solid rear axle.
But wait, there is much more. Back in the early days of Trans-Am racing some teams tried to add negative camber to the rear solid axles by finding ways to bend the axle housings. This worked, but had a useful life of only a few races before the axle bearings bit the dust.
Cortex has produced a genius solution:
By rotating a wedge circular spacer they can add camber to the rear wheel hub. OK, so what about the problem with burning out the axle bearings?
They have axles with a CV joint built in that allows for the change in angle at the hub.
This allows for the solid axle to have suspension characteristics that were once seen as impossible.
They haven’t lost sight of adjustability for the front suspension either so that camber, caster, and bump steer can be optimized.
It is amazing to see how far things have come with suspension re-engineering.