I know we've discussed this before, but I find there's a significant difference in front end grip with increased pressures, provided the roads are smooth enough to not to induce even worse bump steer. In my opinion, higher pressures prevent quite so much sidewall flex which starts off the higher speed under steer. I guess in fact that with all these steering fixes now available, we might be able to lift pressures with less compromise. In Germany I ran 28psi for spirited driving, but had to go back to 22psi or lower when back on those dreadful Belgian roads.
I plan to try the Blockley front tyres next time, as I am told they improve grip. I might also experiment with rear tyre pressure in an attempt to reduce grip a little - that might redress the balance slightly?!
I took the car out yesterday to warm it up before parking up in the kitchen and the roads were quite wet. I had to take an acute right hand turn on a Y-junction to avoid a messy jam and it was clear that the rubbish steering lock would require a 5-point turn to get round. But on the slippery surface, a little assertiveness with clutch and throttle had the car spin in a satisfying 270deg arc (finished off with a dab of oppo.....!), proving the affectiveness of reduced grip at the back. Not really of relevance to the discussion, but reminds me why the car is so fun. Laughed out loud for the next 5 mins - can't do that in Vorsprung durch Technik!!!
I put the front pressures up to 1.9 bar (27.5 psi) and went for a blast on my ride-and-handling route, which takes about an hour and has a variety of surfaces from super-smooth to seriously b*ggered by tank transporters/frost/etc.
This is definitely an improvement, noticeably more neutral (and I think there is an improvement in steering feel), but understeer is still what the car wants to do. I certainly would not want to raise the pressures further, as there is already noticeably increased deflection over the rougher surfaces.
I shall wait until I have the steering kit on and then decide the next step after that: uprated Spax, super-Suplex, or Empire...