Porsche applied turbocharging to its racing cars in 1972 and, within a year, this technology had crossed over into it's production cars: the first road-going 911 Turbo was unveilled at the Frankfurt Motor Show in 1973.This books describes the evolution of turbocharging from racing to road cars.It details the technical and design development of the air-cooled models from 930 to 993 along with exclusive interviews with Klaus Ludwig, Jochen Mass and Nick Heidfeld.Includes full specification tables for each key model type and 300 photographs including many taken specially for this book by renowned photographer Antony Fraser.