Originally Posted by
mk2 cossie
wilwood and hispec both do 4pot calipers that have the mechanical handbrake section in them
wilwood range also has a single piston caliper like the original sierra rear caliper that looks like a 4pot caliper as well
surely if the rears are working that hard, the bias is wrong or the fronts arent working as they should? maybe differing pad materials front to back?

Yes it was Hispec calipers! No the bias is good because the difference is shown after some heavy use (130mph to 40 lets say 3-4 times in short period) and I have same pads materials front and back (Ferodo DS2500).