Renault Sport wanted more, however. To get around strict regulations for Group B rally cars, it decided to change capacity class and produced just 20 units of the ultimate version of the R5 Turbo, the Renault Maxi 5 Turbo. The car was again radically different from its predecessor: steel body shell, aluminium roof, stiffened panelling and wind-tunnel designed and tested bodywork. Brake discs were cast-iron ventilated, wheel rims were made of one-piece magnesium, and wing pillars combined as air-intake ducts. Engine-wise, the 1,527 cc turbo-charged unit supplemented by a DPV anti-lag system borrowed from F1TM could produce 350 hp. With a weight of just 905 kg, it also had excellent power-to-weight ratio.