Sports car racing Group 4 (racing)

a porsche 911 competing in group 4 special grand touring car category @ 1970 1000 km nürburgring

in 1966 , 1967 group 4 sports cars played supporting role group 6 prototypes. while prototypes 7.0l ford gt40 mk ii & mk iv raced outright victories, 4.7l gt40 mk entries competing group 4 class wins. indeed, competitors in 2 categories competing 2 different championships, group 6 cars international championship sports-prototypes , group 4 cars international championship sports cars. in 1968, rules changed, prototypes limited 3.0l, sports cars of 5.0l still entered. announced minimum production figure group 4 sports cars reduced 25 cars 1969. larger engines prototypes, group 4 cars in contention outright race wins. ford gt40 winner @ le mans in both 1968 , 1969. porsche began work on production run of 25 cars porsche 917. ferrari, financial fiat, produced similar ferrari 512.

for 1970 season, group 4 sports car category renamed , became group 5 sports cars , group 4 designation applied new special grand touring category. new group 4 contested production based cars such ferrari 365 gtb/4 daytona, porsche 911 carrera rs , de tomaso pantera.

the group 4 gt category replaced new group b gt class 1983.