An improved chassis with better fuel efficiency from a Bosch Motronic electric system was developed for 1984, being termed the 956B. In total, twenty-eight 956s would be built by Porsche from 1982 to 1984, with an unofficial 29th chassis built from spare parts by Richard Lloyd Racing. The 956 was also the first Porsche to have ground effect aerodynamics. As a comparison, the ground effects Porsche 956 produced over three times as much downforce as the older model Porsche 917 that raced over a decade earlier.