that changed the rocker arm front suspension to a more streamlined pull-rod, rising rate suspension. A thinner longitudinal gearbox was also designed and developed to replace the transverse gearbox to promote better undisturbed airflow from the underside of the ground-effects chassis's side-pods. 126C2B (1983) Mandatory flat bottoms for the cars were introduced for , reducing ground effect, and a redesigned "B" spec. version of the 126C2 was introduced with this in mind. This car was built and raced for the first half of the 1983 season. Postlethwaite designed an oversized but effective rear wing that recovered around 50% of the lost downforce, whilst further compensation came from the engineers who boosted the power of the engine even further, to around in qualifying and over 650 bhp for racing, generally regarded as the best power figures produced in 1983. 126C3 (1983) The 126C3 was first introduced for the British Grand Prix at Silverstone in 1983, with Patrick Tambay, while Arnoux would get to drive a 126C3 at the subsequent race in Germany at Hockenheim, which he ended up winning. Postlethwaite kept the oversized rear wing of the 126C2B, and over the season, Frenchmen Patrick Tambay and René Arnoux scored four wins between them and were both in contention for the world championship throughout 1983, but late unreliability cost them both. However, Ferrari took the constructors' title for the second year in a row. 126C4 (1984) In the season McLaren introduced their extremely successful MP4/2 car, which was far more effective than the 126C4 and dominated the year. The 126C4 won only once in 1984 at the Belgian Grand Prix at Zolder where Villeneuve had been killed in 1982, driven by Italian Michele Alboreto who won his first race for the team. Alboreto also scored the team's only pole position of the season at Zolder. Ferrari ultimately finished as runner up in the constructors' championship, some 86 points behind the dominant McLarens and 10 points clear of the Lotus-Renaults. While the 126C4's engine was powerful at around in qualifying making it virtually the equal of the BMW and Renault engines (and more power than McLaren had with their TAG-Porsche engines), the car itself produced little downforce compared to its main rivals with both Alboreto and Arnoux claiming all season that the car lacked grip. This also had an effect on the cars' top speeds at circuits such as Kyalami, Hockenheim and Monza