For 1997, the FIA replaced the Group A formula with a new formula called World Rally Car. This gave teams greater latitude in design and materials including vehicle width, suspension geometry, aerodynamics, intercooler capacity and engine modifications. This led to a totally redesigned car, the WRC97, featuring modified camshafts, cylinder ports and combustion chambers. The new body had two doors. The width of the car increased to 1,770 mm (69.9 in) with a revised suspension geometry. Power increased to 300 hp @ 5500 rpm, and torque was now 347 lb ft.
Source: Wikipedia (original)