The Alfa Romeo 33 Stradale is a mid-engine sports car built by Italian automobile manufacturer Alfa Romeo. It was the fastest commercially available car for the standing kilometer upon its introduction.Alfa Romeo 33 Stradale turns 50, is still the most beautiful car ever...: Alfa Romeo 33 Stradale turns 50, is still the most beautiful car ever... , accessdate: 19. June 2019 18 examples were produced between 1967 and 1969. "Stradale" (Italian for "road-going") is a term often used by Italian car manufacturers to indicate a street-legal version of a racing car; indeed the 33 Stradale was derived from the Tipo 33 sports prototype. Built in an attempt by Alfa Romeo to make some of its racing technology available to the public, it was also the most expensive automobile for sale to the public in 1968 at ().
Background
Sportscar racing from 1966 onwards was divided into Group 6 "prototypes" with hardly any limitations until maximum engine size was reduced to 3 liter after 1967. If at least 50 cars were built within 12 months, they could be homologated as Group 4 "sports cars", like the already existing Ford GT40 Mk.I and Ferrari 250 LM from the GT era. Homologation requirements were carrying a spare wheel, space for luggage, ignition lock, lights, wipers and other things not found in pure racers but in potentially street legal cars. Already in early 1966, Porsche succeeded in making, selling, and homologating over 50 Porsche 906 Carrera 6 for the 2 liter class. Customers could compete with it as sports car for class wins, while the factory raced improved prototypes and developed it into the Porsche 910. On the other hand, in the same 1966/67 time frame, Ferrari failed to make enough of its 2 liter V6 Dino 206 S, having to race it as prototype. Anyway, in addition to the 33 as prototype racers, Alfa in September 1967 announced that a batch of 50 new Group 4 cars would be constructed, the Stradale. Like Ferrari with the 206S, Alfa did not achieve the required number for homologation despite the number being lowered to 25 in 1969, while many Dino 206 GT and 246 GT were built by Ferrari as road cars, and a series of 25 Ferrari 512S in 1970.
History The 33 Stradale was based on the Autodelta Alfa Romeo Tipo 33 racing car. The car, designed by Franco Scaglione, and built by Carrozzeria Marazzi, made its debut at the Paris Salon de L'Auto on 5 October 1967.The Revs Institute: The Revs Institute – The Revs Institute, accessdate: 6. June 2019
The first prototype (chassis no. 10533.01) was built at Autodelta's workshop in Settimo Milanese, side by side with the Tipo 33 "Periscopica" race car in 1967. The body was built by Franco Scaglione and his team from Carrozzeria Marazzi, while Autodelta worked on the technical aspects of the car. Work to manufacture another magnesium bodied prototype (chassis no. 10533.12) (intended for street racing) was started by Scaglione. However, Marazzi did not finish this until 1968. The two prototypes are the only ones to have the dual headlight arrangement. This was redesigned by Scaglione on the production cars due to regulations on minimum headlight distance from the ground.
The two prototypes carry the project's original serial numbers, 105.33.xx. However, the Tipo 33 racing and production cars got 750.33.0xx (racing) and 750.33.1xx (Stradale) chassis numbers. Marazzi claims to have built 18 chassis. 5 of them were used for 6 concept cars (one chassis was used twice) by Pininfarina, Bertone and Giugiaro/Italdesign and 8 were used for production cars. The rest of the chassis numbers are not confirmed due to a lack of available information as the exact number (allegedly 18) of actual Stradale-chassis (with a 10 cm longer wheelbase than the race cars) doesn't quite match the range of chassis numbers.
The production version of the 33 Stradale was introduced at the Sport Car Show in Monza, Italy in September 1967. The prototype (chassis No. 105.33.01) was sold to the Gallery Abarth in Japan. The second magnesium bodied Stradale prototype (chassis No. 105.33.12) and the five concept cars are now part of the Alfa Romeo Museum.
Specifications Body and chassis The 33 Stradale is considered the first road-going production vehicle to feature forward- and upward-opening butterfly doors, hinged both at the base and on top of the windshield-frame, allowing the 33 Stradale to also feature side windows which seamlessly curve upward into the roof/canopy of its body. Most cars feature an aluminium body on an aluminium tubular chassis. As a result of being built by hand, each model differs from the others in some details. For example, the position of the windscreen wiper, and some of the later cars having vents added behind both the front and rear wheels to allow hot air from the brakes to escape is a differentiating factor. The car has Campagnolo magnesium-alloy wheels – the front and the rear wheels are wide respectively; the brakes used are disc brakes manufactured by Girling, the rear ones are inboard. The suspension system of the car is directly derived from the Tipo 33 race car, with upper and lower control arms in the front and double trailing arms in the rear, along with substantial anti-roll bars.
+Technical specifications Type 90° DOHC V8 Displacement Bore x stroke 78mm x 52.2mm Power at 8,800 rpm Torque at 7,000 rpm Top speed 0–100 km/h (62 mph)less than 6 seconds (untested)
Engine and transmission The race-bred engine bore no resemblance to the mass-produced units in Alfa Romeo's more mainstream vehicles. The engine is closely related to the V8 of the Montreal, albeit with a smaller displacement and a higher power output. The engines, despite being derived from the Tipo 33 racer cars, differed in many details. For example, the 33 Stradale's engines had chain driven camshafts as opposed to the racers' gear driven ones, but the Stradale kept the racing engine's flat plane crankshaft, whereas the Montreal engine had a crossplane crank. Race engineer Carlo Chiti had designed an oversquare bore x stroke of while the all-aluminum V8 engine was dry-sump lubricated featuring SPICA fuel injection with four ignition coils and twin spark plugs per cylinder. The engine used four chain-driven camshafts to operate the 2 valves per cylinder valvetrain featuring dual overhead camshafts and had a rev-limit of 10,000 rpm with a compression ratio of 10.5:1 The engine has a maximum power output of at 8,800 rpm and at 7,000 rpm of torque in road trim and in race trim. Due to the hand-built nature of the drivetrain, the power output levels can vary by each car produced, for example the first production Stradale (No. 750.33.101) has a factory datasheet that states a power output of at 9,400 rpm with a "street" exhaust and with open exhaust. The transmission is a 6-speed unit similar to the Tipo 33 race car, designed by Colotti Trasmissioni.
Although the Stradale is a road legal car, it has some limitations which may make the everyday use slightly hard, for example missing locks and limited ground clearance.
Performance The car takes less than six seconds to attain from a standing start and has a claimed top speed of . In 1968, the German Auto, Motor und Sport magazine measured a top speed of and 24.0 seconds for the standing kilometer which made it the fastest commercially available car for this distance at the time. It achieved this using an engine less than half the displacement of those in high-performance contemporary sports cars such as the Lamborghini Miura, Ferrari Daytona, and Maserati Ghibli.
Gallery
Concept cars Six concept cars were built on 33 Stradale chassis with bodies designed by various Italian coachbuilders.
NameDesignerDebutDimensionsChassis no.Alfa Romeo CaraboMarcello Gandini at Bertone1968 Paris Motor Show750.33.109Alfa Romeo P33 Roadster Paolo Martin at Pininfarina1968 Turin Auto Show750.33.108Alfa Romeo Iguana Giorgetto Giugiaro at Italdesign1969 Turin Auto Show750.33.116 Alfa Romeo 33/2 Coupé Speciale Leonardo Fioravanti at Pininfarina 1969 Paris Motor Show750.33.115Alfa Romeo P33 Cuneo Paolo Martin at Pininfarina1971 Brussels Motor Show750.33.108 Alfa Romeo 33 Navajo Marcello Gandini at Bertone1976 Geneva Motor Show750.33.117
Bertone
Alfa Romeo Carabo
The Carabo is a wedge-shaped coupé with scissor doors and was unveiled in 1968 at the Paris Motor Show. It was designed by Marcello Gandini working under Bertone, who had already built his reputation by designing the Lamborghini Miura.
Alfa Romeo Navajo
The Alfa Romeo Navajo concept car was unveiled at the 1976 Geneva Motor Show held in March of that year. It was given a full fibreglass coupé body with a wedge design, typical of the 1970s, and features such as active front and rear spoilers, as well as headlights which extend horizontally from the fenders. The car is equipped with the 2-litre fuel injected (SPICA) V8 engine producing around at 8,800 rpm.
Pininfarina Between 1968 and 1971, Italian design house Pininfarina designed a total of three vehicles on 33 Stradale chassis:
Alfa Romeo P33 Roadster The Alfa Romeo P33 Roadster was presented to the public at the Turin Motor Show in November 1968. It was an open-top vehicle with a lower windscreen and a roll bar at rear painted in the colour of the body of the car. The chassis was re-bodied two years later to produce the Cuneo.
Alfa Romeo 33/2 Coupé Speciale
The Alfa Romeo 33/2 Coupé Speciale, also known as Alfa Romeo 33.2, was first presented to the public at the Paris Motor Show in 1969. This 2-door coupé was designed by Leonardo Fioravanti, then working at Pininfarina. It bears a striking yellow paint scheme and featured hydraulically operated butterfly doors and pop-up headlights. The design was influenced by the Ferrari 250 P5 concept shown a year earlier at Geneva.
Alfa Romeo P33 Cuneo
The Alfa Romeo Cuneo, originally called 33 Spider at Pininfarina, was by designed by Paolo Martin. It is an open-top, wedge-shaped concept and was presented at the Brussels Motor Show in January 1971.
Italdesign
Alfa Romeo Iguana
The Alfa Romeo Iguana, designed by Italdesign Giugiaro, was presented at the Turin Motor Show in November 1969. It is a two-seater sports coupé built on chassis No. 750.33.116. The design showed some new elements that Giugiaro introduced later in production vehicle designs. The body of the Iguana was painted a metal-flake grey, while the roof frame and cabin pillars were finished in brushed metal, a treatment Giugiaro later applied to the DMC DeLorean. The front end of the Iguana inspired the designs for the Maserati Bora and Merak, and the rear of the car with its high-mounted tail lights formed the basis of the design of the Alfa Romeo Alfasud Sprint. Allegedly, a small series production of the Iguana was planned, but it never materialized.
In popular culture A 33 Stradale can be seen in the 1969 Italian movie Un bellissimo novembre.
See also Alfa Romeo 33 Stradale (2023) Alfa Romeo Montreal Ferrari Dino Lancia Stratos
Notes
References
External links
German article of Stradale with chassis numbers Brief story and original pictures about the 33 Stradale and five of the derived concepts