Adios aerofoils, enter aerodynamics
Authors
- Mattijs Diepraam, Felix Muelas
Date
- 8W March 1999 issue
Related articles
- Lotus - The rise of a phenomenon, by Mattijs Diepraam/Felix Muelas
- Michael May - Aero joke had the last laugh, by Mattijs Diepraam/John Cross
Who?Jochen Rindt What?Lotus-Cosworth 49B Where?Montjuich Park When?1969 Spanish GP |
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Why?
Every once in a while, the modern race fan should be wondering why it is so often that F1 cars race around today with practical 100 ft gaps separating them, making no attempt whatsoever to pass the car in front. Here are these advanced speed machines performing on a world podium and yet they sit there waiting for their pit strategy to do the overtaking. It can't be for nothing that the sport is still called motor racing, can it?
The answer to this ever-recurring question lies in the aftermath of the 1969 Spanish GP. A horrendous crash by Jochen Rindt in his Lotus, having lost its aerofoil at high speed - exactly at the same spot where team mate Hill had lost his wings and crashed several laps earlier - could, and should, have nibbed the breakthrough of aerodynamical downforce in the bud that opened when in 1965 Jim Hall showed up with wings on his CanAm Chaparral, an experiment that no-one had picked up on since Swiss engineer-cum-racer Michael May tried a moveable wing on top of his Porsche RSK some nine years before.
In 1967 the first wing experiments were seen in F1 and from Spa '68 on high wings became de rigueur, lap times decreasing with several seconds. Didn't the governing body take action after the worrying wing failures at Montjuich Park? Oh, yes, with Rindt in hospital the CSI banned the use of high aerofoils in practice at Monaco almost immediately after. But at the same time it opened an appropriate gap by allowing wings to be mounted on the chassis structure itself. The seeds had been sown.
1970 saw the advent of big rear wings or 'tea trays', taking the first small part of what makes a car stick to asphalt from the land to the sky. Luckily, this did not make an end to spectacular racing, since the growing amount of downforce was countered by the quick rise in wheel size, rear wheels especially exploding in the early seventies. Furthermore, slick tyres were introduced so that mechanical grip - the grip directly coming from the car's contact with the track surface - remained the most important factor, as opposed to the aerodynamical grip created by the car's wings, splitters and diffusers and its aerodynamically efficient design.
Ground effects - the most horrid of Colin Chapman's evil inventions - then caused a sizeable shift to aerogrip, which has increased in weight ever since.
The nineties have been a triumph for aerodynamics. As an aerodynamicist, the decade's most successful designer, Adrian Newey, is Chapman's true heir as the Wizard of Downforce. Newey's designs not only look the part but for their success mainly have their aerodynamic efficiency to thank for. With the abandoning of slick tyres, F1 has moved even further away from mechanical grip, the grooves obliging the designers to put even more emphasis on aerodynamics.
So why does this lead to less overtaking? The answer is simple: aerodynamics create downforce best in clear air. Trying to get into the slipstream of the car in front means loss of downforce and thus an ill-handling car that will be all over the place, the driver these days incapable of correcting the slide by lack of mechanical grip. Grooved tyres just aren't built to take the job on. So every driver out for success is wise to sit out his time and wait for his pit crew to pull out all the stops. Some excitement...
For the drivers it can't be much fun either, as was testified by Damon Hill a couple of years ago. After having watched a video of GP highlights from the early seventies, he beamed: "That's what we need! Throw on some of those big, big rear tyres and get rid of the downforce. I mean, get rid of it!" Pity Max Mosley and the FIA Technical Committee don't seem to understand that simple physics lesson.
Reader's Why by Robert Blinkhorn
This race marked the end of the beginning in the race for aerodynamic advantages. During the event, staged on the Montjuich Park street circuit in Barcelona, Hill and Rindt crashed heavily in unrelated incidents. Both accidents were caused by wing failure and resulted in massive damage to their cars. Both men were extremely lucky to survive without major injury. Rindt had taken pole in his Lotus and was leading when his wing collapsed and sent him ploughing into the barrier. His team-mate Hill had already suffered a similar fate on lap eight. Rindt's retirement left Amon out in front, where he stayed for over thirty laps before his engine simply died. That handed the race to Stewart who made it two from two for the season. Stewart's car was the Matra MS80, which incorporated the fuel tanks in side-pods, thus concentrating the weight of the car in the centre, making it extremely stable. The adjustable front wings, mounted on the suspension, increased in angle with acceleration and gave the car excellent grip. Rindt and Hill were not the only casualties from wing failures with Ickx also suffering from the same problem.
The spate of accidents forced the CSI to take action at the next race - held at Monaco. As the cars rolled out of for the Thursday practise session in Monte Carlo most were stilled fitted with wings and the CSI called for an emergency session to discuss the situation. It was decided that the unrestricted use of wings would be banned from all races - effective immediately. The ruling was not well received by the teams who argued that cars designed to use wings would be unstable without them. Their fears proved unfounded and the race passed off without the spate of accident seen in Spain.