Nigel Mansell, Williams, Imola, 1992

Banned! Active suspension

Banned!Posted on | Author Keith Collantine

Active suspension was perhaps the final great innovation of the Lotus team under Colin Chapman. It was a means of keeping the car’s ride height level despite the constant bumps and undulations of Grand Prix circuits, to maximise grip and aerodynamic efficiency.

Lotus’ began developing the idea before his death in the winter of 1982. Ten years later an active suspension car run by a different team finally carried a driver to the world championship.

After that, it was not long before the system was banned.

1981-88: Aborted

Satoru Nakajima, Lotus, 1987Active suspension has its roots in the row over ground effects and skirts in 1981 – and the controversial banning of the Lotus 88.

The teams were searching for means of running skirts down the sides of the cars to generate massive downforce as air passed underneath the car. An essential part of this was ensuring an even ride height – though that had particular value even for non-ground effect cars.

It also had road car applications, and to begin with Lotus developed an early active suspension system on an Esprit Turbo.

These early attempts at active suspension were more ‘reactive’ – using hydraulics to alter the car’s attitude in response to bumps in the road or particular inputs from the driver rather than actually preparing the car in advance for each specific change in the track. The first two iterations of the system (the second driven by Nigel Mansell occasionally in 1983) did not even use springs.

In the mid-1980s it proved extremely difficult to harness the potential of the system because the team lacked the capacity to adequately process the reams of data it produced. This was during the pioneering days of in-car electronics – much of which was concentrated on managing the efficiency of the thirsty turbo engines.

By 1987 Lotus had progressed far enough with the system to consider running it for a whole season. Ayrton Senna was tasked with assessing the active-ride 99T and gave it the thumbs-up.

The system presented the team with two significant drawbacks: First, it added 10-12kg to the car’s weight. Second, it drew power from the car’s engine to run the hydraulic pump.

These shortcomings, combined with other deficiencies in the chassis, meant the Lotus-Honda was far less competitive than the Williams that used the same engines. Mansell and Nelson Piquet in Williamses won the British Grand Prix by over a lap from Senna and team mate Satoru Nakajima.

The active system did pay Lotus back though – at the bumpy Detroit street circuit Senna gave the system its first Grand Prix win, which he followed up with a second at another street circuit, Monte-Carlo.

Williams, however, were developing a system of their own which was more limited in the scale of its ambitions than Lotus’s. It consumed less power (about 5bhp) and Piquet gave an active Williams its first win at Monza – after Senna had gone off.

The following year Lotus ditched the system but Williams persevered – having lost Honda power the team needed a competitive advantage. But active suspension wasn’t it and Mansell grew increasingly frustrated with the technology.

It culminated in the team performing a rush job to convert his car from active to conventional suspension on the eve of the British Grand Prix – before Mansell went out to score an excellent second place, equalling the team’s best result of the year. Active suspension was buried, for now.

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1991-2: Refined

Nigel Mansell, Williams, Imola, 1992Such was the ferocious pace of computer technology development that by 1991 Williams were once again flirting with the technology. In the intervening period Mansell had gone to and returned from Ferrari, and his misgivings about the system persisted.

Late in the season the team produced a ‘B’ version of its FW14 chassis featuring refined and genuinely active – rather than reactive – suspension. Now the car’s attitude could be pre-programmed to anticipate changes in elevation and bumps. (Previously Lotus had conjured up the imaginative idea of using lasers or radar to ‘read’ the track ahead.)

Williams brought the FW14B to the final round of 1991 at Adelaide, but the foul weather prevented them from assessing its capabilities.

But in the off-season they found the car was so astonishingly fast they wouldn’t need to run the FW15 at the beginning of the season. As it turned out, the FW15 wasn’t even needed until the next year.

At the first round of the 1992 season Mansell took pole position from Senna, in a conventionally-suspended McLaren, by 0.741s. The Englishman won the race by 24s from team mate Riccardo Patrese, who was in turn a further 10s ahead of Senna. It set the pattern for the season.

At the bumpy Hermanos Rodriguez circuit in Mexico Mansell’s qualifying advantage over the next non-Williams was 0.946s. At Interlagos the gap was 2.199s. At Catalunya, 1.005s – Williams were on a different planet.

In front of his home crowd at Silverstone Mansell really wound it up and was on pole by 1.919s – from Patrese! Senna was 2.741s adrift and everyone else was at least three seconds slower.

The season was a Williams rout, and rival teams complained that the cost of researching and developing their own active suspension systems would be huge.

1993: Banned

Damon Hill, Williams-Renault FW15C, Monza, 1993For 1993 it was clear that active suspension was essential and almost every team had their own version of the technology. Williams, who had an all-new driver line-up of Alain Prost and Damon Hill, continued to dominate. Only the inspired Senna seriously disrupted Prost’s success.

But the FIA were concerned by the rising cornering speeds and began to pressure the teams into accepting a ban on active suspension for 1994. To underline their seriousness at the Canadian Grand Prix they issued what would become a notorious statement.

Stewards bulletin number three, issued by Charlie Whiting, held that all cars with active suspension were in breach of the current regulations – never mind the future ones. He insisted that the hydraulic rams that formed part of the system were ‘moveable aerodynamic devices’, which had long been banned.

It caused uproar among the teams and media. There were fears the French Grand Prix would have to be cancelled while the teams built new passive cars from scratch, and Williams loudly complained that it could call their 1992 titles into question.

But President Max Mosley’s concerns about the safety of the systems was illustrated dramatically by a number of accidents.

At Spa-Francorchamps for the Belgian Grand Prix Alessandro Zanardi was heading into the ultra-fast Eau Rouge section when a leak in his Lotus’s hydraulic system caused the bottom of the car to hit the track. The car went straight on into the barriers at enormous speed.

The paddock gravely feared that the worst fate had befallen the Italian – his team even had his car transported out of the country in case he died and a criminal investigation began. Astonishingly, he survived – but the terrifying consequences of active suspension failure were clear for all to see.

The system was banned for 1994. Although technology purists may lament its passing, it’s questionable whether the mechanics who actually worked on the systems cared for it all that much.

Former Benetton mechanic Steve Matchett makes several references in his books to his dislike of working with hydraulics that threatened to discharge hot oil in him at a pressure of 2,500psi if the wrong component was disconnected at the wrong time.

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Images © Honda, Williams/LAT