I've been looking at upgrading the Z3 suspension for some time now. Any time I ran into someone who'd upgraded their suspension, I'd pick their brain about what they liked and what they didn't like. During my last trip to Laguna Seca, I talked with Lester regarding his M-Roadster. He opted to go with a Ground Control set up, and he's been very happy with it. He said it offered a lot more adjustability than other packages he'd considered
When I got back home, I looked up
Ground Control (GC) and studied their offerings. Once I'd decided on what I
wanted (singly-adjustable front and rear), I called them up and arranged to visit
their facility (just a few miles from home). They were very helpful, showing me
the parts they manufacture, and all what comprises one of their packages. They
asked me what sort of driving I'm interested in, and based on that they selected
the appropriate spring rates for the front and rear.
I eventually placed my order for a package with their strut housing and doubley- adjustable front/rear. They were out of the rear shocks that I'd need, but they offered to fill the order with singly-adjustables in the rear and then I could upgrade later if I was still interested.
So, today I drove up to the GC shop and picked up the package. Initial impressions:
very, very nice! The rear shock mounts, coil seats and ride-height adjustment fixtures are
beautifully machined. The aluminum parts are tastefully anodized, and the strut
housings are painted to match the Koni shocks. They provide an allen wrench for
ride-height adjustment and a knob for adjusting the shocks. The strut and strut
cartridge were pre-assembled, and some assemblies bundled together to help avoid
confusion during installation. Finally, they preset the adjustments on all four
corners based on our discussions.