For the 1974 racing season, Porsche presented two new versions of the 911 for racing customers: the Carrera RS and the Carrera RSR. The second was the more powerful version, with a 3-liter 911/75 engine that developed about 330 horsepower. The RSR, homologated in Group 4, immediately became an ideal car for teams such as Georg Loos or Kremer. The Carrera RSR experienced a very wide use in any type of competition and even after being replaced in Porsche's catalogue by the 934 in 1976, it continued its career for several more years.