Bugatti Type 35
The Bugatti Type 35 is an iconic Grand Prix race car introduced in 1924 by Ettore Bugatti at the company's Molsheim, France, factory, renowned as the most successful racing car in history with over 1,000 victories.[1] Featuring a lightweight design with a dry weight of 750 kg and an innovative 2.0-litre straight-eight engine producing 95 PS, it achieved top speeds of around 190 km/h, revolutionizing open-wheel racing through its balance of speed, handling, and reliability.[2] The model's ellipsoid aluminum bodywork, cast alloy wheels with integrated brake drums, and advanced engineering elements like a hollow front axle and roller-bearing crankshaft set new standards in automotive design and performance.[3] Developed during the early years of the Grand Prix era, the Type 35 debuted at the 1924 French Grand Prix and quickly dominated circuits worldwide, with variants including the naturally aspirated Type 35A (75 PS), supercharged Type 35C, and the high-performance Type 35B featuring a 2.3-litre engine with up to 140 PS and speeds exceeding 215 km/h.[2] Over 340 units were produced, many driven by legendary figures such as Louis Chiron, Tazio Nuvolari, and Alberto Divo, who piloted the car to five consecutive Targa Florio wins from 1925 to 1929 and the 1926 World Manufacturers' Championship.[2][4] Notable triumphs also included the 1929 Monaco Grand Prix by William Grover-Williams in a Type 35B and the 1929 Grand Prix des Nations at the Nürburgring by Chiron, showcasing the car's versatility across road courses, hill climbs, and sprints.[4] The Type 35's legacy endures as a cornerstone of Bugatti's heritage, influencing the engineering philosophy of modern hypercars like the Chiron and Divo, with its emphasis on precision craftsmanship and racing pedigree remaining central to the brand's identity a century later.[3] Replaced by the Type 54 in 1931, surviving examples continue to command attention at historic races and auctions, symbolizing an era when innovation and artistry converged in motorsport.[2]History and Development
Origins
In the early 1920s, Ettore Bugatti envisioned a versatile Grand Prix car that would dominate international racing through superior engineering and lightweight construction, reflecting the post-World War I shift toward innovative, high-performance automobiles that balanced power with agility. This vision was shaped by the automotive industry's recovery and the growing emphasis on motorsport as a platform for technological advancement and brand prestige.[5][6] Building on the success of the Bugatti Type 30, introduced in 1922 as the company's first production eight-cylinder model, Ettore sought to refine its proven straight-eight engine layout for greater reliability and speed in competitive environments. The Type 30's achievements in hill climbs and reliability trials demonstrated the potential of Bugatti's inline-eight design, inspiring further evolution toward a more specialized racing machine.[6] Development began in earnest at Bugatti's Molsheim factory in France starting in 1923, where key design meetings and prototype testing laid the groundwork for the Type 35. Early sketches focused on the straight-eight engine, incorporating advanced features like a roller-bearing crankshaft for enhanced durability, while prototypes such as the Type 32—nicknamed the "Tank de Tours" for its streamlined, low-slung body—were rigorously tested on local roads and tracks to validate concepts. These efforts emphasized lightweight materials, including hollow axles and cast aluminum wheels, alongside aerodynamic efficiency to outmaneuver heavier rivals like Alfa Romeo's P1 series and Sunbeam's Grand Prix entries.[6][7]Introduction and Early Competition
The Bugatti Type 35 made its public racing debut at the French Grand Prix in Lyon on August 3, 1924, marking the introduction of Ettore Bugatti's innovative grand prix car to international competition. Five factory-entered Type 35s, powered by a naturally aspirated straight-8 engine producing around 90 horsepower, competed on the 23.1-kilometer Lyon-Givors road circuit over 35 laps, drawing over 100,000 spectators. The drivers included experienced works pilots Jean Chassagne (car #7), Ernest Friderich (#13), and Bartolomeo "Meo" Costantini (#22), alongside privateer Léonce Garnier (#21) and amateur Pierre de Vizcaya (#18), with a sixth prototype held in reserve.[8][9] Despite demonstrating exceptional speed, the cars faced significant teething problems, including tire failures due to manufacturing defects in vulcanization and poor quality control from the initial supplier. Costantini retired after 17 laps due to steering failure, while de Vizcaya crashed out on lap 11 and Garnier was flagged off after 33 laps for being too far behind; only Chassagne (7th, 7h 46m 26s) and Friderich (8th, 7h 51m 45s) finished the race. These results highlighted the Type 35's potential for competitiveness against established rivals like the Delage 2LCV and Alfa Romeo P2, even as mechanical unreliability prevented stronger finishes.[8][9] In response to feedback from the Lyon event, Bugatti implemented prompt modifications to address the identified weaknesses, including switching to a new tire supplier for better durability and refining the cooling system to mitigate overheating risks. These changes were validated through rigorous testing, with Ettore Bugatti personally driving a modified Type 35 over 520 kilometers at an average of approximately 100 km/h without issues. The improvements paid off quickly in the car's next outing at the San Sebastián Grand Prix on September 28, 1924, where Costantini secured the Type 35's first podium with a second-place finish and another fastest lap, underscoring the model's rapid evolution and growing reputation in European grand prix circles. By early 1925, further tweaks to suspension geometry enhanced handling stability, setting the stage for dominant performances in events like the Targa Florio, where the Type 35 claimed victory in May.[8][5][10][11]Design Features
Chassis and Bodywork
The Bugatti Type 35 utilized a lightweight pressed steel ladder-frame chassis that integrated the engine as a stressed member to enhance structural rigidity while minimizing mass. This design supported rigid axles at both ends, with the front featuring a hollow axle through which leaf springs passed, and the rear employing a live axle that dipped centrally around the frame before rising to the wheel hubs. Suspension was achieved via inverted quarter-elliptic leaf springs, providing effective roadholding and precise steering without excessive complexity. The complete chassis and body assembly weighed approximately 750 kg, a figure achieved through meticulous engineering that prioritized performance without sacrificing durability.[3][12] Bodywork on the Type 35 consisted of sleek aluminum alloy panels forming a low-drag ellipsoid shape, which encapsulated the rear suspension for a streamlined appearance and reduced aerodynamic resistance. The iconic horseshoe-shaped arched radiator grille, emblematic of Bugatti's aesthetic, was positioned low to optimize airflow while maintaining the car's compact profile. At the rear, a tapered "Bordino tail" fin contributed to high-speed stability by aiding airflow management. These elements combined to create a cohesive exterior that balanced form and function, setting a benchmark for racing car aesthetics.[3][12] A key innovation in the Type 35 was its cast aluminum-alloy wheels, the first of their kind in a production racing car, which replaced traditional wire wheels to drastically cut unsprung weight and improve handling responsiveness. Each wheel incorporated an integral brake drum and was secured via a bolted hub design, allowing for quick tire changes during races. This advancement not only enhanced cornering agility but also contributed to the car's overall lightweight ethos, enabling superior track performance.[3][12]Engine and Transmission
The Bugatti Type 35 featured a straight-8 engine with a single overhead camshaft actuating three valves per cylinder—two inlet and one exhaust—for efficient gas flow and high-revving capability up to 6,000 rpm.[13][2] This monobloc design incorporated five main bearings (two roller and three ball) supporting the crankshaft for durability under racing stresses.[3] An optional Roots-type supercharger with three-lobe rotors, introduced in 1926 for supercharged variants like the Type 35C, provided forced induction, drawing air through the intake system for enhanced performance.[2] Power delivery was managed by a wet multi-plate clutch comprising 10 plates, ensuring smooth engagement between the engine and transmission during high-speed shifts.[14][2] The four-speed manual transmission, with a separate casing and sliding-gear mechanism, transferred torque via a propeller shaft to the rear axle, optimizing drive efficiency in a rear-wheel-drive layout.[15][14] Fuel was delivered via twin Solex carburetors (or a single Zenith in supercharged variants) positioned for updraft intake, supporting both naturally aspirated and supercharged configurations with precise metering for combustion.[16] The system included a mechanical fuel pump for reliability under competition demands. For the base model, splash lubrication with a mechanical pump circulated oil via jets to maintain pressure; supercharged variants employed dry-sump lubrication with dual pumps and an additional cooler mounted ahead of the front axle to prevent starvation during cornering.[14] Cooling relied on an arched honeycomb radiator—characteristic of Bugatti's horseshoe styling—paired with a centrifugal water pump to dissipate heat from the inline-8 effectively.[14] This powertrain integrated seamlessly with the chassis for balanced weight distribution, enhancing handling without compromising mechanical integrity.[2]Grand Prix Racing Variants
Type 35
The Bugatti Type 35 represented the original naturally aspirated Grand Prix racing model, debuting at the Lyon Grand Prix on August 3, 1924, and establishing the core design principles for Bugatti's dominant era in motorsport.[17] This variant prioritized lightweight construction and agile handling for the demanding circuits of the 1920s, setting it apart from prior road-derived racers by being purpose-built for competition from the outset.[3] Its shared chassis framework with other early Bugatti designs emphasized durability under high-speed stress, as detailed in the broader design features section. At the heart of the Type 35 was a 1,991 cc straight-8 engine with a single overhead camshaft operating three valves per cylinder—two overhead intakes and one side exhaust—delivering 95 hp at 5,000 rpm and a compression ratio of 5.5:1.[18][19][20] This powerplant, fed by a single Zenith carburetor, provided reliable performance suited to the era's 2-liter formula regulations, enabling top speeds of approximately 175 km/h (109 mph) on the straights of European road courses.[20] The engine's compact, inline configuration contributed to the car's balanced weight distribution, enhancing its cornering prowess without the complexity of forced induction. Production of the Type 35 spanned from 1924 to 1926, with approximately 96 units constructed at Bugatti's Molsheim factory, destined primarily for factory entries and privateer teams in Grand Prix events.[21] These limited numbers reflected the model's racing exclusivity, with each chassis hand-assembled to exacting standards for immediate track deployment rather than mass-market appeal.[2] Key racing adaptations distinguished the Type 35 for Grand Prix circuits, including friction-type shock absorbers adjustable via onboard controls to fine-tune ride stiffness for varying track conditions.[22] The suspension employed semi-elliptic leaf springs at the front and inverted quarter-elliptic leaf springs at the rear, paired with these dampers to absorb high-speed impacts while maintaining precise handling.[23][20] Complementing this was a lightweight body crafted from hand-beaten aluminum panels over a steel-alloy chassis, minimizing weight to around 700 kg and optimizing power-to-weight efficiency for superior acceleration out of corners.[24] This combination of features propelled the Type 35 to early victories, such as multiple class wins at its debut Lyon event, cementing its role as a benchmark in pre-war racing engineering.[17]Type 35C
The Bugatti Type 35C, introduced in 1926, represented a supercharged development of the base Type 35 architecture to boost Grand Prix competitiveness during the mid-1920s. This variant retained the core ladder-frame chassis and eight-spoke wheels of its predecessor while incorporating forced induction to address the increasing power demands of international racing regulations. Approximately 38 units were produced between 1926 and 1930, reflecting Bugatti's focused output on high-performance racing machines.[25] Central to the Type 35C's design was its 1,991 cc straight-eight engine, fitted with a Roots-type supercharger and twin Zenith carburetors for enhanced aspiration. This configuration delivered 128 hp at 5,000 rpm, enabling a top speed of around 201 km/h. The engine featured a cast-iron block and head with a single overhead camshaft operating a three-valve-per-cylinder layout (two intake, one exhaust) at a compression ratio of 5.2:1, contributing to improved efficiency under boost. To handle the stresses of supercharging, the crankshaft was supported by two additional roller bearings for greater durability.[26][5] Bugatti provided factory support for Type 35C entries in major events, including the European Grand Prix series, where the model helped secure the manufacturer's 1926 World Championship title through multiple victories. By 1929, the model's list price had reached 91,500 French francs, underscoring its status as a premium racing tool amid ongoing refinements for reliability and performance.[4][27]Type 35B
The Bugatti Type 35B represented the culmination of the Type 35 Grand Prix lineage, the final supercharged variant developed during the 1926-1927 AIACR formula era (1.5 L supercharged or 2.0 L naturally aspirated), using a low-boost supercharger on the enlarged engine for performance equivalence.[28] Building on the supercharger technology introduced in the Type 35C, the 35B featured an enlarged straight-8 engine with the stroke increased from 88 mm to 100 mm (bore remaining at 60 mm), yielding a total displacement of 2,262 cc. This configuration, equipped with a Roots-type supercharger driven at engine speed, delivered 138 horsepower at 4,500 rpm, enabling a top speed of approximately 125 mph.[29][30] To handle the elevated torque from the supercharged setup—estimated at around 140 lb-ft—the Type 35B incorporated a reinforced four-speed gearbox with stronger synchromesh components, addressing the durability issues seen in earlier models under high-load conditions. The chassis retained the classic 94.5-inch wheelbase and quarter-elliptic leaf-spring suspension of the Type 35 series, but with subtle refinements for better torque distribution. Cooling was enhanced through a larger radiator and enveloping cowling, often referred to as the "Miramas" design, which improved heat dissipation during prolonged high-revolution operation, crucial for the era's extended race durations.[29][5] Production of the Type 35B spanned from 1927 to 1930, with approximately 37 units constructed at the Molsheim factory, making it one of the rarer Grand Prix variants in the series. These cars were primarily campaigned in international events, where their power and reliability shone in demanding scenarios beyond standard circuits. Notably, the 35B excelled in hill climbs, such as the outright victory at the 1928 Mont Ventoux ascent by driver Robert Benoist in chassis 4848, completing the 21.5 km course in 17 minutes 38 seconds. Additionally, examples set multiple speed records in the late 1920s, including class wins at events like the Shelsley Walsh hill climb, underscoring the model's versatility for sustained high-speed efforts on varied terrain.[29][31][23]Type 39
The Bugatti Type 39 represented a compact evolution of the Type 35 Grand Prix racer, tailored specifically for the lighter displacement classes in international competition. Derived from the established Type 35 design, it was engineered to compete in Voiturette events governed by AIACR regulations, emphasizing agility and reliability in secondary racing formulas.[32] This variant prioritized a reduced overall scale while retaining core Bugatti engineering principles, making it suitable for circuits demanding quick handling, such as Monza.[33] Central to the Type 39 was its naturally aspirated straight-8 engine, displacing 1,493 cc with a bore and stroke of 60 mm by 66 mm, single overhead camshaft, and three valves per cylinder. This powerplant produced 80-90 horsepower at around 5,500 rpm, providing sufficient output for its class without forced induction.[32][34] The engine featured a roller-bearing crankshaft and was fed by a single Zenith or Solex carburetor, contributing to its reputation for durability during endurance-oriented Voiturette races.[35] Paired with a four-speed manual transmission and mounted in a ladder-frame chassis with rigid axles, it enabled competitive performance in events like the Grand Prix de Boulogne.[32] The Type 39's chassis incorporated a wheelbase of 2,400 mm, slightly refined from the Type 35 for enhanced maneuverability in tighter corners typical of junior formula tracks.[35][32] Suspension employed inverted quarter-elliptic leaf springs at the front and semi-elliptic at the rear, with four-wheel cable-operated drum brakes integrated into cast-aluminum wheels. Bodywork was kept minimal and lightweight, typically in aluminum with a low-slung, open two-seater configuration to reduce weight to approximately 750 kg and optimize aerodynamics for high-speed stability.[36][37] Production was strictly limited, with only 10 units constructed between 1926 and 1929 at the Molsheim factory, underscoring its role as a specialized racing tool rather than a mass-produced model.[32] These cars saw success in Voiturette-class events, including podium finishes in Italian and French grands prix, validating Bugatti's approach to scaling down the Type 35 for smaller-capacity competition.[33][36]Road and Special Variants
Type 35A
The Bugatti Type 35A served as a detuned, road-oriented adaptation of the Type 35 Grand Prix racer, tailored for private customers desiring spirited performance suitable for touring and daily street driving.[38][2] Its powerplant was a 1,991 cc naturally aspirated straight-8 engine, derived from the Type 38 touring unit but with reduced compression for improved reliability and lower maintenance demands compared to the high-strung racing versions.[38][39] This configuration delivered around 70-75 horsepower at 4,000 rpm, providing ample power for road use while emphasizing durability.[38][2] Production spanned from 1925 to 1929, with 139 units built at the Molsheim factory, each fitted with practical road features including full weather equipment, electric lights, and a softened suspension system featuring leaf springs and friction dampers to enhance comfort over varied surfaces.[38][39] The Type 35A proved popular among European enthusiasts for its blend of the Type 35's racing pedigree and touring refinements, with buyers often selecting options like cycle fenders for a sportier aesthetic and convertible tops for versatile open-air motoring.[38][2]Type 35T
The Bugatti Type 35T was a short-production variant of the Type 35 grand prix racer, specifically adapted for the grueling Targa Florio endurance event on Sicily's mountainous roads. Developed in early 1926, it built upon the base Type 35 platform to address the race's unique demands, including steep gradients and prolonged high-speed running over rough public roads.[5] Central to the Type 35T's design was its 2,262 cc naturally aspirated straight-8 engine, achieved by increasing the stroke to 100 mm while retaining the 60 mm bore, which emphasized low-end torque for better hill-climbing capability over outright top speed. This powerplant, producing around 100 hp, was mated to a four-speed transmission with adjustments suited to the terrain's variable demands. The chassis retained the lightweight ladder-frame construction of the Type 35 but incorporated enhancements for durability on uneven surfaces, while the rear-mounted steel fuel tank held 100 liters to enable extended operation without frequent refueling during the multi-lap race.[40][41] Only 13 examples of the Type 35T were constructed, all destined for Targa Florio competition, limiting its use beyond the Sicilian event due to evolving grand prix regulations capping engine displacement at 2.0 liters. These cars featured minimal bodywork for reduced weight and drag, with dust-mitigating seals on critical components to combat the fine road dust prevalent in the race environment.[41] The Type 35T played a key role in Bugatti's unbroken streak of Targa Florio victories from 1925 to 1929, with a factory-entered example securing the 1926 win driven by Meo Costantini ahead of teammate Ferdinando Minoia in second place driving a Type 35.[4][42] This success underscored the variant's effectiveness in endurance racing, where reliability and tractability proved more vital than peak power.Type 37
The Bugatti Type 37 served as a more accessible road-going variant of the Type 35, designed to appeal to a wider audience beyond dedicated racers by offering scaled-down performance in a practical sports car package. Production ran from 1926 to 1932, with 223 units manufactured at the Molsheim factory, making it one of the more numerous models in Bugatti's early lineup. Marketed as a "pur-sang" sports car—emphasizing its pure-bred engineering heritage—the Type 37 typically featured an open two-seater body style that balanced simplicity and elegance for everyday motoring.[43][44][45] The Type 37's powerplant was a 1,496 cc straight-four engine derived from the earlier Type 30's architecture, delivering 60 hp at 4,500 rpm through a single overhead-camshaft design with a Zenith carburetor. This naturally aspirated unit provided reliable output for road use, paired with a four-speed manual transmission and rear-wheel drive. Its chassis drew brief design influences from the Type 35, including a low center of gravity, but utilized a lighter 2,400 mm wheelbase to enhance maneuverability and reduce overall weight to around 700 kg.[46][44][43] Key features of the Type 37 included cable-operated drum brakes on all four wheels, with larger drums introduced on later examples for improved stopping power, though Ettore Bugatti preferred mechanical systems over emerging hydraulic options. Buyers could opt for customizable coachwork, often configured as touring variants with added windshields or lightweight panels to suit grand touring needs, underscoring the model's versatility for affluent private owners.[47][48][46]Type 37A
The Bugatti Type 37A served as the supercharged iteration of the Type 37, tailored for enthusiastic road use with enhanced performance capabilities. Building on the base Type 37's 1,496 cc straight-four engine design, the Type 37A incorporated a Roots-type supercharger to boost output, along with reinforced internals such as a stronger billet crankshaft to handle the increased stresses.[48][49] This configuration delivered approximately 80-90 horsepower at 5,000 rpm, enabling a top speed of around 125 mph while maintaining the model's lightweight chassis and agile handling for dynamic driving experiences.[48][50] Production of the Type 37A spanned from 1927 to 1930, with roughly 67 examples constructed out of the broader Type 37 series total of about 290 units.[51][48] These vehicles were primarily offered in open tourer or Grand Prix-style bodies, though buyers could opt for custom enclosed coachwork for greater weather protection and improved ventilation systems to address the supercharger's heat generation during prolonged spirited runs.[52] The original list price hovered around 55,000 French francs, positioning it as a premium yet accessible choice for affluent motorists seeking Bugatti performance on public roads.[52] Although oriented toward road applications, select Type 37A examples saw occasional competitive use in hill climb events, where their boosted power and compact dimensions proved advantageous on twisting ascents.[50] This versatility underscored the model's appeal as a bridge between everyday motoring and light motorsport, contributing to its enduring reputation among early enthusiasts.[49]Technical Specifications
Engine Configurations
The Bugatti Type 35 series featured a family of inline-eight engines renowned for their compact design and high-revving capability, all sharing a monobloc cast-iron construction with wet cylinder liners for efficient cooling and durability. These engines employed a single overhead camshaft (SOHC) driven by a vertical shaft, actuating three valves per cylinder—two overhead intake valves and one side-mounted exhaust valve—for a total of 24 valves across the bank. This valvetrain configuration allowed for reliable operation at speeds up to 6,000 rpm, balancing airflow and simplicity in a racing context.[53][18] Engine displacements varied across variants to meet different regulatory and performance needs, starting from smaller units for entry-level or road-oriented models and scaling up for Grand Prix competition. The base Type 35 used a 1,991 cc displacement, producing approximately 90 PS (about 89 hp) in naturally aspirated form through twin Zenith carburetors and a compression ratio of around 5.8:1.[5] For the more affordable Type 35A, the same 1,991 cc engine was detuned with a three-bearing crankshaft and coil ignition instead of magneto, yielding roughly 75 PS (74 hp) to suit sporting but less demanding applications.[2] The Type 39, a downsized evolution for smaller races, reduced displacement to 1,496 cc while retaining the SOHC setup, delivering 80-90 hp at 5,500 rpm.[35] Supercharged variants introduced forced induction to boost power significantly, with the Type 35C adding a three-lobe Roots-type blower to the 1,991 cc engine, increasing output to 120-130 PS (118-128 hp) via approximately 0.5-0.7 bar of boost pressure.[2] The largest configuration appeared in the Type 35B and Type 35T, both at 2,262 cc; the former incorporated the Roots supercharger—mounted low on the offside with a driver-engaged clutch for selective activation—achieving up to 140 PS (138 hp) by late production, while the latter relied on natural aspiration for specific events like the Targa Florio.[5] Tuning refinements, such as a five-bearing crankshaft in higher-output models and aero-grade fuel in later iterations, enhanced reliability under boost, though fuel consumption typically ranged from 20-25 L/100 km in mixed use due to the thirsty supercharger setup.[23]| Variant | Displacement (cc) | Aspiration | Power Output (PS/hp) | Key Tuning Notes |
|---|---|---|---|---|
| Type 35 | 1,991 | Naturally Aspirated | 90 / 89 | Twin Zenith carbs, 5.8:1 compression |
| Type 35A | 1,991 | Naturally Aspirated | 75 / 74 | Three-bearing crank, coil ignition |
| Type 35C | 1,991 | Supercharged (Roots) | 120-130 / 118-128 | ~0.5 bar boost, magneto ignition |
| Type 35T | 2,262 | Naturally Aspirated | ~100 / 99 | Longer stroke (100 mm) for torque |
| Type 35B | 2,262 | Supercharged (Roots) | 130-140 / 128-138 | Driver-engaged clutch, five-bearing crank |
| Type 39 | 1,496 | Naturally Aspirated | 80-90 / 79-89 | Compact bore/stroke (52 x 88 mm) |