Ever since I've taken the car to the track I have not really been happy anymore with the shocks. I have the feeling they don't have enough low speed damping, what makes the car roll quite a bit when turning into a corner and it also dives a bit much during braking. But then I started thinking about what else to use than the Koni shocks.
I have been thinking about getting a Gaz Gold or Black Art Design coilover set. As far as I know both are twin tube shocks with 1-way adjustment that combines compression and rebound damping in 1 adjuster. For both you hear quite a lot of good stories, mostly a bit better for the BADs than for the Gaz, but sometimes people are still saying they are not happy with them, or that the damping is not very equal for all shocks. Another option is the old type of Bilstein coilover as Ford used on the works cars back in the day. Those use monotube shocks with 41 mm inserts, which is supposed to be a better damper principle than the twin tube from Gaz, BAD and Koni. I would expect the quality from the Bilstein to be better than Gaz and BAD, but unfortunately the Bilsteins are not adjustment in damping and the 41 mm inserts are quite rare and therefore pricey now. Another option was to use 40 mm custom inserts from Bilstein and build my own shock housing. Quite a lot of parts can easily be bought, so especially a front coilover wouldn't be so difficult to make, but they still wouldn't be adjustable just like the 41 mm inserts. Yet another option was to a set from for instance Proflex or Reiger. Both are monotubes like the Bilsteins, but adjustable. Both will be very good as they are used in professional motorsports, but unfortunately the price will also reflect that.... So the last option was to find a second hand Proflex or Reiger set which would be more affordable. My preference would then go to Reiger, as Ford have been using them in the World Rally Championship since 1997, starting on the Escort WRC. The only problem is that Reigers for a Cosworth are impossible to find second hand. Proflex seems to be a bit easier to find second hand, so that is what I got in the end.
As these are quite old by now they are only 2-way adjustable, compared to the 3-way adjustability of new Proflex dampers. These have independent compression and rebound adjustment. On the new ones you can adjust low and high speed compression independently as well. But if I ever wanted it would be possible to convert these 2-ways into 3-ways adjustment.