Ferrari 250 Testa Rossa
The Ferrari 250 Testa Rossa, or 250 TR, is a sports racing car built by Ferrari from 1957 to 1961. It was introduced at the end of the 1957 racing season in response to rule changes that enforced a maximum engine displacement of 3 litres for the 24 Hours of Le Mans and World Sports Car Championship races. The 250 TR was closely related to earlier Ferrari sports cars, sharing many key components with other 250 models and the 500 TR.
The 250 TR achieved many racing successes, with variations winning 10 World Sports Car Championship races including the 24 Hours of Le Mans in 1958, 1960, and 1961, the 12 Hours of Sebring in 1958, 1959 and 1961, the Targa Florio in 1958, the 1000 Km Buenos Aires in 1958 and 1960 and the Pescara 4 Hours in 1961. These results led to World Sports Car Championship constructor's titles for Ferrari in 1958, 1960 and 1961.
Design and development
The 250 Testa Rossa was initially developed to compete in the 1957 World Sportscar Championship racing season, in response to rule changes planned for the upcoming 1958 season that would enforce a maximum engine displacement of 3 litres. The objective was to improve on the existing 4-cylinder 2.0L 500 TR/500 TRC Testa Rossa by integrating the more powerful Colombo-designed 3.0L V12 as used in 250 GT series. Along with the new engine, Ferrari improved the existing Testa Rossa chassis and bodywork. As with other Ferrari racing cars, Enzo Ferrari demanded absolute reliability from all components, resulting in a somewhat conservative design approach that aimed for endurance racing success through durability rather than overall speed. Carlo Chiti was the chief designer during 250 TR development and his continual experimentation counterbalanced Mr. Ferrari's conservatism and led to the many revisions that kept the car competitive through 1962. Other Ferrari engineers had major contributions to the 250 TR, notably Giotto Bizzarrini, who helped with aerodynamic improvements for the 1961 season, and Andrea Fraschetti, who helped develop the first 250 TR prototype before his 1957 death during a test drive.The 250 TR was raced and continually developed by Scuderia Ferrari from 1957 through 1962. In total, 33 250 TRs of all types were built between 1957 and 1962. Included in this total are 19 "customer versions" of the 250 TR sold to independent racing teams, replacing the 500 TRC for this market. All customer cars had left hand drive Scaglietti "pontoon fender" bodies and live rear axles. They did not benefit from the continual improvements to Scuderia Ferrari cars, although many independent teams modified their 250 TRs or purchased ex-Scuderia Ferrari cars in order to stay competitive.
Engine and drivetrain
The 250 Testa Rossa engine was based on Colombo-designed 3.0L V12 used in 250 GT road and racing cars. Carlo Chiti and other Ferrari engineers made several modifications to increase the performance of this already proven engine. The starting point was a 1953-style cylinder block with an overall capacity of 2953 cc, a 73 mm bore and 58.8 mm stroke. Six two-barrel Weber 38 DCN carburetors fed the engine, increased from the 3 carburetors typical for 250 GT engines. The cylinder heads used single overhead cams, 2 valves per cylinder and helical double-coil valve springs.The helical valve springs were much smaller than previously used torsion springs, allowing the cylinder heads to be strengthened and secured with 24 studs rather than 18 in previous 250 engines. This increased the overall reliability of the engine by improving head gasket sealing. One spark plug was used per cylinder and the position was changed from earlier 250 designs, now located outside the engine vee between exhaust ports. This allowed for a better spark position and more efficient combustion. Piston connecting rods were now machined from steel billet, rather than forged, which resulted in more stress-resistance at higher RPM. The cam covers were painted bright red, the source of the name "Testa Rossa". This tradition and name originated with the 500 TR.
The resulting engine was designated Tipo 128 and generated at 7000 rpm. The power/displacement ratio of 100 hp/litre was a particular point of pride for Ferrari, as it demonstrated how Ferrari's engineering prowess could create a competitive engine even under rules restricting displacement. The engineering team improved a well understood, proven design by incorporating new technology and strengthening known weak points. They created an exceptionally durable engine, a massive benefit in endurance racing. Other Ferrari racing cars achieved racing success with the same basic engine well into the 1960s, years after the 250 TR chassis was obsolete.
1957–1958 250 TRs used a 4-speed transmission, followed by a 5-speed transmission in 1959. Customer cars were equipped with a 250 GT-style transmission positioned directly behind the engine, while Scuderia Ferrari team cars sometimes used rear-mounted transaxles for better weight distribution.
Chassis, brakes and suspension
The 250 Testa Rossa used a tubular steel spaceframe chassis, similar to that used in the 500 TR. Compared to the 500 TR, the wheelbase was extended by 10 cm to 2.35 meters. The chassis gained a reputation for durability, as it was designed according to Enzo Ferrari's desire for absolute reliability even at the expense of excess weight.All 250 TRs used independent front suspension with coil springs. All customer cars had live rear axles. Pre-1960 factory team cars used either live or de Dion rear axles while the 1960 250 TRI60 and 1961 250 TRI61 used independent rear suspension.
1957 and 1958 250 TRs were equipped with drum brakes on all four wheels. Enzo Ferrari insisted on the use of drum brakes in the early 250 TRs as he believed they were more reliable and predictable in how they faded compared to more powerful but relatively new disc brakes. Drum brakes were unpopular with drivers as they required tremendous physical exertion to operate, due to lack of servo assist and the extremely hard, long-lasting pads used for endurance races. Despite the extensive air cooling used in the 1958 "pontoon fender"-bodied cars, drum brakes were still subject to heat-induced fade. They were finally replaced with Dunlop disc brakes in all Scuderia Ferrari cars for the 1959 race season.
Bodywork and interior
All 250 TRs had 2-seater spider bodies, as did the earlier 4-cylinder Testa Rossas. At the time, this was considered the lightest and most aerodynamic configuration for a racing sports car.The first 250 Testa Rossa prototype debuted at the 1957 Nürburgring 1000km. This hastily prepared prototype was based on a 290 MM chassis and had conventional bodywork by Scaglietti very similar to that of the 4-cylinder 500 TR, except for a large hood bulge.
For the 1958 250 TR, new bodywork was developed in collaboration between Scaglietti and Chiti with several innovations on the previous 4-cylinder Testa Rossa body. Instead of the conventional fully enclosed front end, the new body had a distinctive cut-away nose reminiscent of a Formula 1 car. The protuberant central air intake was now flanked by deep channels and the headlights were set into nacelle- or pontoon-like fenders that enveloped each front wheel. The purpose of this design was to funnel cooling air inwards towards the brake drums, mitigating the persistent problem of heat-related fade. The lower body was recessed inwards behind the front wheels in order to vent heat from the brakes and exhaust. The front hood was topped with a large bulge and air intake to provide clearance for the vertically oriented carburetors. The rear bodywork was more conventional, including a tapered fairing behind the driver's head and two small brake lights set into vertical fins.
The distinctive cutaway-nose bodywork of the 1958 cars became the most iconic 250 TR style and was used on all cars sold new to private customers. This resulted in the colloquial name for early Scaglietti-bodied 250 TRs: "pontoon fender." Despite their radical appearance, racing and test runs soon showed that this design generated a significant amount of aerodynamic drag and high speed instability. This was especially noticeable when competing on high speed courses such as the Circuit de la Sarthe against more aerodynamic cars such as the Maserati Tipo 61 and Jaguar D-Type. As a result, the Scaglietti bodywork was soon revised and a wide variety of alternative styles were created from 1958 through 1961. Even during 1958, some Scuderia Ferrari cars were equipped with more conventional bodies in the style of the 1957 prototype.
The 250 TR's open interior was simple and utilitarian, lacking the luxury trimmings found in Ferrari GT cars. The instrumentation and controls were completely focused around the driver. Like other 1950s and 1960s Ferrari sports cars, 250 TRs were equipped with an open gated shifter and a Nardi wooden steering wheel.
Variants and further development
The 250 TR was subject to continual iteration and refinement from 1957 to 1961, resulting in numerous differences between individual cars that may or may not coincide with different chassis production dates. As was common with Ferrari racing cars of the 1950s and 1960s, 250 TRs were frequently modified and updated by the Ferrari factory and/or private owners. Bodywork was often changed to improve performance or to repair crash damage. Ferrari historians track these changes with a numbering suffix based on year of production as well as descriptors such as "Spider Fantuzzi" to denote cars with bodies fabricated by Fantuzzi. Despite this historiographical systematization, the low-production, hand-built nature of these cars and their use and modification in period mean that differences are most thoroughly explained in the context of an individual chassis' history.1959: TR59
For the 1959 season, the 250 TR body design was lightly revised by Pinin Farina, with fabrication of the bodies handled by Fantuzzi. The cutaway nose with pontoon fenders was gone, replaced by a more aerodynamic design that still incorporated many ventilation grilles and air inlets.The 1959 250 TR was the first Ferrari sports car to use disc brakes. Disc brakes are much less susceptible to heat build-up and fade than drum brakes, so the extra air cooling provided by the 1958 Scaglietti body was no longer necessary.
A 5-speed transmission mounted directly behind the engine was also introduced in 1959.