Ferdie: May I ask what significantly transformed the handling in your opinion? Did you use the EU or US spec Alpina suspension?
It was probably all of them taken together.
We used the EU-spec Alpina springs and dampers and I suspect they provided the majority of the improvement. This can be intuited from old US magazine road tests where the Alpina version was thought to handle better from back-to-back testing with a standard Z8. The Alpina progressive-rate springs have more variability in their rate than do the standard springs. The front Alpina USA springs were actually the USA Z8 springs due to headlight and bumper height regulations, thus necessitating the EU-spec conversion. All the Alpina vehicles I have ever driven seem to steer with more precision and handle better than their donor vehicles.
The Dinan caster plates add more self-centering to the steering feel and make the car track subjectively truer as one goes down the road.
The Michelin PS2's are a world apart from the OEM run-flat tires, which felt like they were made from concrete.
Cheers,
--
Mike
2005 Carrera GT - Signal Yellow + 2008 Tesla Roadster - Thunder Gray +1972 BMW 3.0 CSi - Nachtblau +2009 Bentley Arnage T - Black Saphire