"Citroën entered Group B rallying with the BX in 1986. The specially designed rally BX was called the BX 4TC and bore little resemblance to the standard BX. It had a very long nose because the engine (a turbocharger fitted version of Chrysler Europe's Simca Type 180 engine) was mounted longitudinally unlike in the regular BX. The engine was downsleeved to 2,141.5 cc (from 2,155 cc) to stay under the three-litre limit after FIA's multiplication factor of 1.4 was applied. The rally version of the BX also featured the unique hydropneumatic suspension, and the five-speed manual gearbox from Citroën SM.[10] Because of the Group B regulations, 200 street versions of the 4TC also had to be built, with a 200 PS (147 kW) at 5,250 rpm version of the N9TE engine.[10]
The 4TC was not successful in World Rally Championship competition, its best result being a sixth place in the 1986 Swedish Rally. The 4TC only participated in three rallies before the Group B class was banned in late 1986, following the death of Henri Toivonen in his Lancia Delta S4 at the Tour de Corse Rally. Already discouraged by the car's poor performance in motorsport and the demise of Group B, Citroën was only able to sell 62 road-going 4TCs; build quality and reliability problems led Citroën to buy back many of these 4TCs for salvage and destruction.[11] With only a fraction of the original 200 examples remaining, the 4TC is now highly sought-after."