Citroen DS23 Series 3 Decapotable by Chapron
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Car producer : |
Citroen |
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Model: |
DS23 Series 3 Decapotable by Chapron |
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Year: |
1967-1973 |
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Type: |
Cabriolet |
In late 1967, for the 1968 model year, the DS and ID was again restyled, by Robert Opron, who also styled the 1970 SM and 1974 CX. This version had a more streamlined headlamp design, giving the car a notably shark-like appearance. This design had four headlights under a smooth glass canopy, and the inner set swiveled with the steering wheel. This allowed the driver to see "around" turns, especially valuable on twisting roads driven at high speed at night.
Behind each glass cover lens, the inboard high-beam headlamp swivels by up to 80° as the driver steers, throwing the beam along the driver's intended path rather than uselessly across the curved road. The outboard low-beam headlamps are self-leveling in response to pitching caused by acceleration and braking.
However, this feature was not allowed in the US at the time (see World Forum for Harmonization of Vehicle Regulations), so a version with four exposed headlights that did not swivel was made for the US market.
This 'turning headlight' feature was new to the market - it had only been seen before on the very rare three headlight 1935 Tatra 77A. 45 years later, it is now a commonly available feature, even in the United States. The Tucker, which never was mass-produced, had a central headlight that turned with the steering.
In a hydro pneumatic suspension system, each wheel is connected, not to a spring, but to a hydraulic suspension unit consisting of a hydraulic accumulator sphere of about 12 cm in diameter containing pressurized nitrogen, a cylinder containing hydraulic fluid screwed to the suspension sphere, a piston inside the cylinder connected by levers to the suspension itself, and a damper valve between the piston and the sphere. A membrane in the sphere prevented the nitrogen from escaping. The motion of the wheels translated to a motion of the piston, which acted on the oil in the nitrogen cushion and provided the spring effect. The damper valve took place of the shock absorber in conventional suspensions. The hydraulic cylinder was fed with hydraulic fluid from the main pressure reservoir via a height corrector, a valve controlled by the mid-position of the anti-roll bar connected to the axle. If the suspension was too low, the height corrector introduced high-pressure fluid; if it was too high, it released fluid back to the fluid reservoir. In this manner, a constant ride height was maintained. A control in the cabin allowed the driver to select one of five heights: normal riding height, two slightly higher riding heights for poor terrain, and two extreme positions for changing wheels. (The correct term, oleo pneumatic (oil-air), has never gained widespread use. Hydro pneumatic (water-air) continues to be preferred overwhelmingly.)
The DS did not have a jack for lifting the car off the ground. Instead, the hydraulic system enabled wheel changes with the aid of a simple adjustable stand. To change a flat tyre, one would adjust the suspension to its topmost setting, insert the stand into a special peg near the flat tyre, then readjust the suspension to its lowermost setting. The flat tyre would then retract upwards and hover above ground, ready to be changed. This system, used on the SM also, was superseded on the CX by a screw jack that, after the suspension was raised to the high position, lifted the tire clear of the ground. The DS system, while impressive to use, sometimes dropped the car quite suddenly, especially if the stand was not placed precisely or the ground was soft or unleveled.
The central part of the hydraulic system was the high pressure pump, which maintained a pressure of between 130 and 150 bar in two accumulators. These accumulators were very similar in construction to the suspension spheres. One was dedicated to the front brakes, and the other ran the other hydraulic systems. (On the simpler ID models, the front brakes operated from the main accumulator.) Thus in case of a hydraulic failure, the first indication would be that the steering became heavy, followed by the gearbox not working; only later would the brakes fail.
Two different hydraulic pumps were used. The DS used a seven-cylinder axial piston pump driven off two belts and delivering 175 bar (2,540 psi) of pressure. The ID19, with its simpler hydraulic system, had a single-cylinder pump driven by an eccentric on the camshaft.
The DS was initially offered only with the "hydraulique" four-speed semi-automatic (bvh—"boîte de vitesses hydraulique") gearbox.
This was a four-speed gearbox and clutch, operated by a hydraulic controller. To change gears, the driver flicked a lever behind the steering wheel to the next position and eased-up on the accelerator pedal. The hydraulic controller disengaged the clutch, engaged the nominated gear, and re-engaged the clutch. The speed of engagement of the clutch was controlled by a centrifugal regulator sensing engine rpm and driven off the camshaft by a belt, the position of the butterfly valve in the carburettor (i.e., the position of the accelerator), and the brake circuit. When the brake was pressed, the engine idle speed dropped to an rpm below the clutch engagement speed, thus preventing friction while stopped in gear at traffic lights. When the brake was released, the idle speed increased to the clutch dragging speed. The car would then creep forward much like automatic transmission cars. This drop in idle throttle position also caused the car to have more engine drag when the brakes were applied even before the car slowed to the idle speed in gear, preventing the engine from pulling against the brakes.
The later and simpler ID19 had the same gearbox and clutch, manually operated. This configuration was offered as a cheaper option for the DS in 1963. The mechanical aspects of the gearbox and clutch were completely conventional and the same elements were used in the ID 19. In September 1970, Citroën introduced a five-speed manual gearbox, in addition to the original four-speed unit.
In September 1970 Citroën introduced a 3-speed fully automatic Borg-Warner gearbox. The full-automatic transmissions were intended for the US market, but Citroën withdrew the DS from the US in 1972, so most automatic DSs, fuel-injected DS 23 sedans with air conditioning, were sold in Australia.
The DS was originally designed around an air-cooled flat-six based on the design of the 2-cylinder engine of the 2CV, similar to the motor in the Porsche 911. Technical and monetary issues forced this idea to be scrapped.
Thus, for such a modern car, the engine of the original DS 19 was also old-fashioned. It was derived from the engine of the 11CV Traction Avant (models 11B and 11C). It was an OHV four-cylinder engine with three main bearings and wet liners, and a bore of 78 mm (3.1 in) and a stroke of 100 mm (3.9 in), giving a volumetric displacement of 1911 cc. The cylinder head had been reworked; the 11C had a reverse-flow cast iron cylinder head and generated 60 hp (45 kW) at 3800 rpm; by contrast, the DS 19 had an aluminum cross-flow head with hemispherical combustion chambers and generated 75 hp (56 kW) at 4500 rpm. Apart from these details, there was very little difference between the engines: even the locations of the cylinder head studs were the same, so that it was possible to put the cylinder head of a DS on a Traction Avant engine and run it.
Like the Traction Avant, the DS had the gearbox mounted in front of the engine, with the differential in between. Thus some consider the DS to be a mid engine front-wheel drive car.
The DS and ID power plants evolved throughout its 20-year production life. The car was underpowered and faced constant mechanical changes to boost the performance of the four-cylinder engine. The initial 1911 cc three main bearing engine (carried forward from the Traction Avant) of the DS 19 was replaced in 1965 with the 1985 cc five-bearing wet-cylinder motor, becoming the DS 19a (called DS 20 from September 1969).
The DS 21 was also introduced for model year 1965. This was a 2175 cc, five main bearing engine; power was 109 hp This engine received a substantial increase in power with the introduction of Bosch electronic fuel injection for 1970, making the DS one of the first mass-market cars to use electronic fuel injection. Power of the carbureted version also increased slightly at the same time, owing to the employment of larger inlet valves.
Lastly, 1973 saw the introduction of the 2347 cc engine of the DS 23 in both carbureted and fuel-injected forms. The DS 23 with electronic fuel injection was the most powerful production model, producing 141 hp (105 kW).
IDs and their variants went through a similar evolution, generally lagging the DS by about one year. ID saloon models never received the DS 23 engine or fuel injection, although the Break/Familiale versions received the carburetted version of the DS 23 engine when it was introduced, supplemented the DS20 Break/Familiale.
The top of the range ID model, The DSuper5 (DP) gained the DS21 engine (the only model that this engine was retained in) for the 1973 model year and it was mated to a five-speed gearbox. This should not be confused with the 1985 cc DSuper fitted with an optional "low ratio" five-speed gearbox, or with the previous DS21M (DJ) five-speed.
Rarest and most collectable of all DS variants, a convertible was offered from 1958 until 1973.
It was an expensive car, so only 1,365 were sold. These DS convertibles used a special frame which was reinforced on the side members and rear suspension swing arm bearing box, similar to, but not identical to the Break (Station Wagon) frame. In total 1,365 d`usine convertibles were produced on the DS19 and DS21 chassis. The Cabriolet d'Usine (factory convertible) were built by French Carrossiers Henri Chapron, for the Citroën dealer network.
One of the most stylish cars of the 1960s, the latter was the creation of Parisian coachbuilder, Henri Chapron, who called his first such model 'La Croisette'. A native of Nouan-le-Fuzelier in the Sologne region of France, Henri Chapron founded his coachbuilding company in 1919 at Levallois-Perret an outskirt of Paris. Unlike so many fashionable French coachbuilders, Chapron carried none of the mental baggage that came from having graduated to cars from building horse-drawn carriages; consequently, his work had a freshness and innate sense of proportion that was well suited to chassis of quality. Chapron's interpretations of the Citroën DS and ID were quite different from the regular production versions. Chapron added fins to the rear wings as early as 1965 and launched his own version of an upmarket DS at the Porte de Versailles Salon de l'Auto in October 1964 using the name 'Majesty'. At first the conversion was not approved by Citroën, forcing Chapron to buy complete cars rather than rolling chassis, but eventually the factory relented and went on to produce its own ursine version on the longer chassis of the ID Break (estate) model. Chapron continued to build his own Le Caddy and Palm Beach convertibles together with various limousines and coupés. The most popular of the latter being 'Le Dandy'. Chapron's second take on a soft-top DS, Le Caddy first appeared in 1959 and represented a considerable improvement over La Croisette. Whereas the latter had used saloon-type rear wings, necessitating a covering strip for the join between the wing and the redundant rear 'door' panel, Le Caddy used a much neater one-piece wing. The saloon's front doors were used until 1960 when longer ones were adopted, resulting in a further improvement in the design's proportions. Only 34 examples of the Le Caddy convertible were built between 1959 and 1968. Needless to say, they are all highly desirable. Chapron manufactured 389 convertibles of his own, the last in 1973. Introduced in 1960 at the same time as Le Caddy and Le Dandy was another variation on the coupé theme, the Concorde, which featured a more generously proportioned cabin with greater headroom for the rear passengers. Only 38 were built over the next five years. In addition, Chapron also produced a few coupés, non-works convertibles and special sedans (including the "Prestige", same wheelbase but with a central divider, and the "Lorraine" notchback).
