Several years ago I was doing research on brake systems with the idea of upgrading the brakes on my white pearl Tiger. This lead to a lot of reading of published information on brake system design and the realization that a pedal mechanical ratio of six to one was essentially an industry standard practice. For reasons that are not clear, the Rootes Group designed the brake system used in Sunbeam Alpines and Tigers with a pedal ratio of approximately four point four to one and added a vacuum/hydraulic booster to obtain acceptable brake pedal pressures.