Instabanned

F1 innovation that was banned immediately

With the Lotus 78 and Lotus 79 models winning the 1978 F1 championship, Colin Chapman had revolutionised his Lotus team and the rest of the pitlane with the development of ground effect cars.

Ground effect cars were essentially cars with upturned wings underneath the sidepods. By sealing the sides with rubber moveable skirts this created a vacuum of low pressure, resulting in enormous amounts of downforce with none of the disadvantages of drag created by front and rear wings.

By 1980 every team up and down the pitlane had ground effect cars in order for them to compete with Lotus. After the success of the 78 and 79 though, Lotus struggled to improve. With the Lotus 80 and 81 the numbers on paper were showing far more downforce at their disposal than before, but instability in downforce would occur during cornering, braking and acceleration. To add to the problems, the FIA announced that moveable side skirts would be banned for 1981 and ground effect cars would be limited to “fixed” sides with a minimum ground clearance of 60mm.

Taking these issues onboard, Colin Chapman pressed ahead and produced the Lotus 86 as a test bed throughout 1980 in readiness for 1981.

In order to get round the instability problem, the car would have to be as stiffly sprung as possible to minimise any sudden roll from the car that could affect the air going to the underside of the car. Making the car as stiffly sprung as possible though made it a rather unpleasant environment for the driver who would feel every knock and jolt with the near zero suspension travel. So the Lotus 88 for 1981 was designed as dual chassis car – one chassis inside the other.

The bodywork, sides and wings were connected to the front and rear wheels with extremely stiff suspension as one “chassis”, while everything else was mounted inside the first as a second chassis. This meant the bodywork and aerodynamic ground effect sides could remain static but everything else could use a softer suspension setup without getting in the way of the ground effect, improving the situation for the driver. Lotus and others even got round the 60mm rule by lowering the car when out on track and raising it when not.

By Andrew Basterfield (Lotus-Cosworth 88B) [CC-BY-SA-2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons
Image credited to Andrew Basterfield (Lotus-Cosworth 88B) [CC-BY-SA-2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons
The 88 turned up for the first race of the 1981 season and while at first it was announced legal, the car was soon shown the black flag in practice and disqualified from the event. The FIA argued that way the 88 was devised was essentially breaking the regulations regarding moveable aerodynamic devices. Lotus then boycotted Imola and the car was not allowed to race at the next 2 Grands Prix before Lotus finally backed down at Silverstone, the 88 never to be seen again. Ground effect cars were then banned completely for 1983.