After
retiring from
F1 at
the end of the 1962 season, Porsche focused again on sports cars. The 904
debuted in 1964 as a successor to the
Porsche 718,
which had been introduced in 1957. The 904 was the first Porsche to use a
fiberglass
body. While many German race cars had used unpainted aluminum bodies
since the famous 1934
Silver Arrows,
most 904s were painted silver, the
German racing color.
The 904 marked the beginning of a series of sports cars that
culminated in the mighty
Porsche 917.
Porsche initially designed
the GTS variant to compete in the FIA-GT class at international racing
events. In 1964 the street-legal version debuted and complied with
GT class homologation regulations requiring a certain number of road
worthy variations be sold. Both versions featured a fiberglass body
bonded to a steel chassis for increased rigidity. The
mid-engine layout was inherited from the Porsche 718 known as the RSK
which was the leading race car for Porsche.
The 1964 models featured an aggressively tuned 180 hp
version of the four-cam, flat four-cylinder "Fuhrmann" engine, originally
designed for race use in the 550 Spyder,
and later the
356 Carrera
engine with 130 hp. To satisfy demand, twenty 1965 models were produced,
some featuring a variant of the
911's flat
six-cylinder engine. The six-cylinder units were identified as the 904/6.
A race prepared four-cylinder 904 weighed approximately 1,443
pounds and could accelerate to 60 mph from a standstill in under six
seconds with a top speed of 160 mph. Since the 904's fiberglass body was
made by spraying chopped fiberglass into a
mold, the
amount sprayed often varied in thickness over the shape of the car and as
a result the weight of the cars was inconsistent. Due to the less weight
issues of the first generation plastic body, the 904's successor, the 1966
Porsche 906
or "Carrera 6", was developed with a tubular space frame covered with an
unstressed, lighter fiberglass body.
Racing
During its debut race season in 1964, the 904 won outright at the
Targa Florio
race in
Italy, one of
Porsche's many wins at the event. Another event during that season
included the winning of first place in P3.0 at
Sebring 12 Hours
by
Briggs Cunningham
and
Lake Underwood.