BMW 3.0 CSL extremely unstable under braking

[Gaudin de Beaufort]

I try to drive the bmw 3.0 csl gr4, but at the slightest brake pressure it spins out of control. I can't imagine this is realistic for a car on 15 inch slicks. It is a huge difference with, for example, the Broadspeed Jaguar (same year and class). I have experimented with the set up, but nothing really helps.
Does anyone have any tips?

 

[Toonces]

You might post your setup, or at least the brake power and balance (and maybe ride-height, spring weights, toe, etc.).