Starting mid-1973, those who missed ordering a 1973 Carrera 2.7 RS had the option of a Carrera 2.7 MFI, or the extremely limited Carrera 3.0 RS. This ultimately led to privateers campaigning the Carrera 2.7 MFI in many significant events including the Targa Florio, Monte Carlo Rally, Acropolis Rally, Rallye Sanremo, Rallye d’Antibes, Rally dell'Isola d’Elba and 24 Heures d'Ypres, among others.

For 2016, Historic Sportscar Racing (HSR) and Jochen Maas have created a special new racing series specifically for Porsche's 2.7 to 3.0-liter RS/RSR models, including the RS-spec Carrera 2.7 MFI built from 1974 through 1975 which shared the typ 911SC designation with the RS models.  Called the "Classic RS Cup", HSR has coined the series of events "A Throw Back To The International Race of Champions (IROC)". To level the playing field, minimum weights for the car and driver are assigned to each displacement model.

The series begins with Virginia International Raceway (May 26-29) followed by Road Atlanta (September 16-18), Hutchinson Island (October 27-30), Daytona (November 10-13) and Sebring (December 1-4). Each event consists of two 25-minute sprint races as well as a 60-minute endurance challenge.

More information is available in the Classic RS Cup booklet and the Classic RS Cup website.