The Ferrari 126C was designed to replace the highly successful but obsolete 312T series in use since 1975. The basic chassis was almost identical to the previous car but the smaller and narrower V6 engine with forced induction, better suiting the ground effect aerodynamics now needed to be competitive (the previous car's wide flat-12 boxer engine obstructed the airflow necessary to generate efficient ground effect), and was a better package overall. During engine development Ferrari started experimenting with a Comprex pressure wave supercharger, supplied by a swiss company; this car version was initially called 126BBC from the name of Brown Boveri Comprex and later named 126CX. The system was praised by drivers for driving like a naturally aspirated engine but having an extended power range, thus eliminating the notorious lag of the turbocharger. However the system was rather tall in the car and there could be some mixing of exhaust and intake gas so the team opted for the fitment of twin KKK turbochargers producing around 600 bhp (447 kW; 608 PS) in qualifying trim, detuned to 550 bhp (410 kW; 558 PS) in race trim. The car fitted with turbochargers was called 126CK.