Ligier JS21

The big bluff

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The JS21 was the single-seater with which the Ligier Gitanes Equip participated to Formula One Championship in 1983, the year when FISA radically changed its technical regulations in consequence of the terrible accidents that took place during the previous Championship. By then it was clear that Wing-cars were increasingly looking like suckers that paid more for the driver's courage than for his ability. Then, if unfortunately something went wrong, they became real wings, able to "take wing", with foreseeable dramatic consequences for the drivers at the wheel of them. And so Formula one Committee, met in Paris, decided to forbid the use of skirts, obliging the racing teams to design cars with flat undersides between the two axis and reducing the weight from 580 to 540 kg. Width of the rear wing was reduced from 110 to 100 cm, with a gap brought to 60 cm with respect to the rear axis (earlier it was 80). Like all other experts, also the French team designers had to design a fully new car, taking the JS19 project only as a base to reduce the costs that big change would have surely involved for them. First two Ligiers, marked "02" and 03, were actually constructed using as a base the modified chassis of the older sister, and the 04 only, the car given to Javier, was completely a new built one. For information only, obviously they also produced a car marked "01" but it was exclusively employed for pre-championship practices. In the wind tunnel at St. Cyr., Michel Beaujon and Claude Galopin studied a single-seater similar to the JS19 in the central part, but completely different in the front and above all in the rear one. As the skirts were no longer allowed, the two transalpine experts decided on the complete elimination of the sides, by only designing two protruding parts before the rear wheels so as to install the water radiators, then ending up by concentrating the masses on the rear area. In any case, that area supported the 80% of weights against the 20% reserved to the front one. The arrow shaped was in fact the easiest one to be constructed and it assured higher sensitivity to the adjustments. From an aesthetic point of view, it was just the rear axle the most interesting part, with the air division into three air flows, each of them having a well defined task. The first had to pass over the body and thanks to two "inlets" wedged itself in towards the oil radiators, the second, intermediate, supplied air to the water radiators and the third had to create ground effect by means of a sophisticated Venturi tube passing under radiators, through the swooping profile which raised up to 60 cm on the rear side. Then the whole was closed by lateral bulkheads that nearly touched the ground. It was also interesting the rear wing, triplane, a novelty for those years, fastened by two rather articulate supports even if then, during the year two variants had be seen, one with a supplementary wing, Toleman type (i.e. fastened before the rear wheels) 140 cm wide and the other with very short chord for fast racing circuits. The original system, according to transalpine experts, had to bring up to the 50% of the ground effect achieved in 1982, that is more than 500 kg (about 280 km per hour). From the technical point of view the most important innovation, which has been adopted on the circuit by the JS21, was the hydro pneumatic shock absorbers system studied with the Citroen experts and already tested in the 60's on the DS 19. The system, adopted both on the front and the rear suspension, made the traditional metallic springs useless, which were replaced by two balls (one for axis) containing Nitrogen and delivered to pressure by the engine that activated a set of pumps which were keeping up the ideal pressure in the hydraulic circuit. The single-seater was only lifted 2.5 cm from the ground when it was parked at the pit, but as soon as the engine was started up and reached 2500 rounds, the hydraulic circuit was delivered to pressure, with the shock absorbers that raised up to reach the height to be required. During an interview given at the Ricard circuit in February, Guy Ligier said that after several practices they realized that minimum height which avoided "doing a belly flop" was 6 cm. Once on the track, an electronic computer and some sensors automatically adjusted the set-up, by operating on a solenoid valve and on some stiffness governors. The purpose of this system was not so much to adjust the set-up as to avoid the pitching of the car when accelerating and braking, made particularly strong on this car by the weight distribution as said before. The system was at least modified in two events: at the beginning of the season they went on a construction betterment, while since the Germany G.P. racing cars had been mounting a system that adopted one ball for wheel instead of one for axis. After first races, the advantages of this type of suspension were causing doubts and transalpine engineers redesigned the whole system with conventional suspensions. On the front wheel suspension they modified both the chassis and the body, with the suspension upper connection "swelled" like the "183 Alfa Romeo" type so as to hold an upper rocker arm, while the rear axle was equipped with a rocker arm, Williams type, and a vertical single-shock absorber unit beside the gear, the whole supported by a cross member in derived fusion from the old JS19. This alternative system was built up on the chassis "01" and carried as a test engine to the GP of England, but it never went to the track. The spring system was made by double overlapped triangles of unequal bases with links and anti-roll bars, given that the two balls were independently operating on each axis but the wheels of each axis interfered among them. The central part of the car was designed to hold the Ford engine, recycled from the Ligier company after the failed agreement with Renault covering the supply of turbocharged engines. The body followed closely the overall dimensions of the engine.

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The engine

At the start of the season the two cars were equipped with the DFV (double four valves) version, but from the GP of Monaco the team got three DFYs (the first series engines with short stroke) alternatively mounted on frame no.4. All over the season this engine of a 15 hp increased power with respect to the previous one, will be reserved for Jarier, the team leading driver. The DFV was the engine shown by Ford in 1982 to challenge the power of supercharged engines. It delivered 495 bhp at 11000 rpm, with 165 hp/litre specific horsepower, 13.5 bar MEP and 23.3 m/s, piston mean speed. The engine structure was left quite similar to the one of the first Cosworth, which made its debut by winning at the 1967 Dutch Grand Prix with Jim Clark, all the more because boring and stroke were left unchanged. In 1982 winter, eng. Mario Illien, a total stranger at that time, who had been on the staff of the Cosworth company since 1979, studied an evolution of the engine, named DFY "short stroke", constructed with magnesium alloys which allowed 5 kg weight reduction. The design envisaged the reduction of the piston stroke from 64.8 to 58.8 mm with the heads in a single unit, with the journals for camshafts and the seats for bucket-type tappets obtained inside. The stroke reduction caused the angle of valves to be brought to 22°30' (against previous 32° ) which was due to 10° of the inlet valves and 12°30' of the exhaust ones. Diameter of valves was also modified, they passed to 36.06 (instead of 34.50) for the inlet stroke and 31.75 (instead of 29.97) for the exhaust one. Rating went up to 510 hp with particular improvements from the point of view of the torque curve which allowed to eliminate the brutality of the engine at 6500 rpm. At the mid-season a further up-rated version was introduced, however used only by the Tyrrell. DFY (short stroke) was available from the French GP for the McLarens and the Lotus car of Mansell while Jarier had to wait till GP of Monaco, where among other things, he broke the new propulsor in test. At the end of the Championship this type of engine was also mounted on the RAM-March car of Acheson kindly lent by McLaren, by that time passed to the most powerful TAGs.

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The JS21 entry was like a "case heard in camera" (or almost) and it happened in early February on Korland circuit at the wheel of Jarier. The JS21 was already the car that would have taken part in the championship but a particular attention was paid to the system of hydro pneumatic suspensions which were thought of uncertain issue. There were many doubts about the name of the second driver; at first Oscar Larrauri seemed to be the favourite but at the end they preferred the billion brought by Boesel who had the advantage of the café do Brazil sponsorship. At the first official debut, which happened on Ricard circuit two weeks later, the Ligier could introduce its whole team and the times obtained were of great interest, just enough to make the special press say that it was a car "born well". Until the GP of Brazil eve, engineers brought the possibility in to question of using hydro pneumatic suspensions in the first races, while Jarier had already made their use sure from the very beginning. And in fact the three cars parked at the Brazilian pits showed Citroen shock absorbers. The car soon highlighted a series of problems caused by the concentration of masses on the rear area, among those the worst one was the overheating, that obliged the technicians to remove the upper underbody. That ended by limiting the envisaged ground effect. In practice Jarier scored a good 12th time but in race he had to retire for troubles to the hydraulic circuit of suspensions. Like his true self Boesel scored the 17th time, but he was obliged to the retirement for a short circuit caused by the battery. The race where Ligier had the best chances was the second round, which took place in the splendid landscape of Long Beach. Jarier, who started the tenth, achieved the 4th place at the 25 lap, but on the next lap he ran into the Rosberg's car that, after an accident, still blocked up the racetrack, and he sadly ended the race at the pit. In this race Boesel came seventh, which was the best score of this car in the space of the season, together with the result obtained by Jarier in Austria. The happy moment went on two weeks after during the Champions' Race on the circuit of Brands Hatch; in a race where only thirteen cars were under starter's order, Boesel was the author of a good race in which he was seen struggling till the last turn to come fourth. On next two racing circuits the car paid especially for the power failure of the engine, but drivers' criticism didn't fail for the difficult handling of the car on speedy big turns and on straights. Things improved on the racing circuit of Monaco, where Jarier obtained the best result in the year during practices, thanks to a new supplementary wing of Toleman type. However it was not taken advantage of the 9th time because the team chose not to risk the tyres from dry ground on a still slippery track. The outcome was that in a few rounds the French driver was taken by the group and he ended by retiring at the 33rd lap for a trouble to a pump of the spring system. With regard to the tyres mounted at the beginning of the race, people say an amusing anecdote: a few minutes before starting, Galopin came up to Beaujon to ask for his opinion about the best tyres to be mounted. The colleague looked at him showing a relaxed air and answered that he hadn't the faintest idea. The team's championship was actually ended during the Week-end of next racing. Guy Ligier obtained the decisive supply of Renault engines for the following year and he immediately decided to start by studying the new car. The JS21 was no longer subject to big changes (of which the car was undoubtedly in need), just enough to remember one only wing with a reduced profile used on speedy circuits beginning from Silverstone and the strengthening of the brakes for Zandvoort. Conventional spring system was put on one side, while the new streamlined shape, envisaged to minimize the problems of roadability at high speed, was never designed owing to a session of practices that took place at Hockeneim, where the car was proved to be very fast on straight. By the end of the year the Ligier company modified the car equipped with conventional shock absorbers by adding some side bellies and let it run so as to test the new components studied for the1984 Ligier-Renault ; at its wheel there was already the new entry Andrea De Cesaris. This last version marked the end of the story of the JS21 car, born to challenge Turbo engines and ended to the car-wrecker of Formula one. But after all, F 1 is full of stories like these ones.

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On Sunday May 15th 2001 we went to the circuit of Monza to observe the car in question and make inquiries to whom is at its wheel during the Troughbread Trophy. It is a championship for vintage cars that every year is run on the Brianza circuit. Let us say, at once, that the car in question cannot be certainly defined as "easy to ride" . Just to look at it from the outside, we can understand how daring the project was, whose results were anything but sure. Hydro-pneumatic system certainly allowed the reduction of pitch movements, which was caused by such an extreme weight splitting, above all when making up on the low-speed stretches, but whereas the car was to run some stretches at full speed it was largely inclined to "sbandierare". Jarier often complained about the scarce roadability of the car on the high speed circuits, whilst he made some appreciations when he found himself on slow speed circuit . To know something more about the matter, we had an interview with Hans Joackim Durstewitz, the owner of the only model car that is still on the stage of racing circuits. To the question I put to him of his opinion on the car, the German driver answered that "the car is very fine and interesting but also impossible to ride. Notwithstanding it is almost always successful in F1 and F Junior races, when I run with that car I can't succeed in going beyond half way of the line up". He adds he has asked for and obtained the car was given on trial to Martin Stretton, that is the star of the series; "the English driver has confirmed same big difficulties of handling as I found out" and he ends by saying: " and it's good that Stretton uses Tyrrell P34, that has already so many roadability problems". Aerodynamics of the car permitted to achieve rather high peak speed if we compare it with competitors who mounted aspirated propulsors but the gap with the competing supercharged engine cars was pitiless: On short Ricard, the Alfas achieved 287,400 km/h whilst the Ligier car recorded 233,400 km/h.

Marco Zanello

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