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STREAMLINING TOOK AWHILE to beat automotive perpendicularity, though its innovations were certainly entertaining, if not entirely successful. Today in Part 2 we admire the Voisin Type 6 Laboratoire and Chenard-Walcker Tank.
Voisin Type C6 Laboratoire. Gabriel Voisin built aircraft for 14 years before he turned to automobiles. For the 1923 French Grand Prix, he too assayed aerodynamics in his Laboratoire, a car replete with innovation.
Voisin’s Laboratoire had a unitary chassis, a monocoque design. Later, he wrote, “I had conceived of a chassis-less design solely from fabricated panels, to which the engine and suspension could be mounted directly. This was a principle I introduced for Tours, creating in the process the first monocoque of the type now adopted the world over.”
Never one to hide his light under a bushel, Voisin neglected to cite the Lancia Lambda, built between 1922 and 1931.
The Laboratoire displayed other innovations beyond its monocoque structure. Panels were of lightweight aluminum. Its narrow rear track eliminated need for a differential. The little propeller up front powered the engine’s water pump. Unlike the Bugatti Type 32’s, the Laboratoire’s front tires were left exposed to enhance the driver’s cornering judgement.
And, according to Revivaler, “If a car is simply shaped like an aircraft wing… it will have a tendency to lift at high speed…. Voisin appears to have understood this and so the front of the car is shaped to create a down-force by directing air upwards.”
“This,” Revivaler continues, “has the effect of creating a low pressure area under the car helping to keep it from any tendency to lift. Similarly the rear treatment of the car has a wing shape to nicely close out the air-flow at the rear but has a slightly up-swept under-section which enhances the creation of a low pressure area under the car…. Voisin and [chief engineer] Lefebvre had in fact created what might be thought of as the first rudimentary ground effect Grand Prix racing car.”
Four C6 Laboratoires contested the 1923 French Grand Prix at Tours. One was disqualified after eight laps; one retired on lap 19; another on lap 29. The remaining Laboratoire finished fifth, the last of 17 starters to survive a grueling 497-mile 35 laps.
Chenard-Walcker Tank. Chenard-Walckers were regular competitors at early Le Mans, the team’s small cars contesting the Rudge-Whitworth Cups, its larger cars going for overall wins (as one accomplished in the inaugural Le Mans, 1923).
Chenard-Walckers of the small variety had a 1095-cc inline-four with pushrod-actuated overhead valves. Those equipped with superchargers could reach 107 mph; normally aspirated variants, 94 mph.
No. 50 finished 10th in the 1925 Le Mans 24-hour race, the third running of this famed event. It covered 1169 miles at an average speed of 48 mph and won the 1924-1925 Biennale Rudge-Withworth Cup. The second small Chenard-Walker, No. 49, came 13th of the 16 classified finishers and garnered the Triennale Rudge-Whitworth Cup.
Streamlined Versus Perpendicular. The Sunbeams that dominated the 1923 French Grand Prix (1st, 2nd, and 4th) were decidedly perpendicular.
Lorraine De Dietrichs took 1st and 3rd at the 1925 Le Mans ; a Sunbeam was 2nd. Lorraine De Dietrichs returned in 1926 to take 1st-3rd. And, like the Bentleys that were to dominate Le Mans 1927-1930, these cars were proudly perpendicular.
It wasn’t until 1937 that a streamlined car, a Bugatti Type 57G Tank, took top honors at Le Mans. ds
© Dennis Simanaitis, SimanaitisSays.com, 2022
Like to know more about the favoured perpendicular style. Could have been in interest of straight line stability as for a fin ?
Amazing the level of understanding that existed so early . I have always commented that aerodynamics is not a science that is easily thumbsucked.
I suspect it was merely following the practice of radiators been big, blunt, and up front.
I hope you extend your musings at some time to the plethora of Panhard, Rene Bonnet, Matra and Gordini LeMans streamliners with tiny engines, seeking the ACO sponsored Index of Performance and Index of Thermal Efficiency prizes that the French so widely publicized and prized.
I always enjoyed the Brockbank cartoon of one of these microstreamliners stuffed into the snout of a hulking Ferrari, etc. The little car pilot had wide eyes, while the big car driver is saying to his mechanic, “It started overheating on the Mulsanne.”
Agreed, interesting. See http://wp.me/p2ETap-4wk. I like the Brockbank.
I always thought it was ironic that in his LeMans movie, Steve McQueen had to swerve and crash his thundering Porsche 917 to avoid a backmarker Porsche 911.