If you inspect a race track and analyse each of the turns attempting to find the fastest way around, eventually you can identify what racers call 'the line'. In simple terms the line is the best way to enter a turn, cross its apex and then exit at the highest possible speed. As you watch a race, you'll see drivers set themselves up for a turn at the outside edge of the track, sweep through to briefly touch the inside kerb of the turn, then accelerate out to the outer edge of tarmac and down the straight.
On most circuits the line is easy to spot, because it is the darker area of the tarmac where the constant stream of traffic has left a trail of rubber on the track. Follow the correct line through each turn and you will be guaranteed a quick, smooth lap. The trick, however, is understanding that the line varies for each type of turn. If every circuit consisted of nothing but constant radius bends finding the line would be simple. But many turns have different angles; sometimes there are two apexes in the same long sweeping corner. Then there are esses - quick left-right bends that throw the car from side to side. Then there are hairpins, turns so sharp that cars must slow to a crawl and hug the inside in order to get round safely.
Take the example of the high speed bend found at the end of the back straight at Interlagos. The best racing line can be seen as three distinct points;
- the turn in point, usually located at the end of the braking zone, is the spot where the car actually enters the corner.
- the apex or clipping point. This is the slowest part of the turn where the car is at its closest to the inside of the corner.
- the exit point when the car is back on a straight line. This is the fastest part of the bend.
In negotiating a turn a driver must try to use as much of the track as possible, including the 'rumble strip' - the run off area on the edge of the tarmac, and his first priority must be to get the power back on as soon as possible.
Compounding the problem for drivers is the fact that everybody else on the track wants to be on the line, so to pass them you've got to find the next-fastest line and hope that your machine can simply 'out-muscle' the other driver.
Examine this shot of the Variante Ascari at Monza. There is only one optimum line to take. This makes overtaking on such bends difficult and cars tend to bunch up and move through corners nose-to-tail.
There are certain constants concerning the way a car will perform on the track, particularly during cornering. For any given set of circumstances, a race car may display one of three cornering tendencies; understeer, oversteer or neutral. Neutral is the ideal situation but it is rarely achieved and virtually never sustained for the duration of a race.
As a car approaches a turn, the driver applies the brakes and then turns the wheel. Grip is reduced at the front, and the car begins to drift towards the outside of the turn. In severe cases of understeer the car will simply not turn properly and shoots off the track.
To control understeer, more grip is needed on the front wheels. This is acheived by easing off on the throttle and allowing the wheels to grip more or by applying the brakes more vigourously, which shifts weight to the front providing more downforce on the front tyres. However as speed is the point of racing that solution is counter-productive. Instead the front wings are adjusted to provide the downforce needed. A car exhibiting understeer can be controlled through the careful use of acceleration andbraking.
As suggested oversteer is the opposite of understeer. That is to say the front wheels have plenty of grip but the back end of the car loses traction. Oversteer is usually caused by an imbalance in the brake bias, worn tyres or incorrect wings. Unlike understeer which normally occurs gradually, oversteer can happen quickly and without warning. If not corrected it will cause the rear end to break loose and the car will enter into an uncontrolled spin.
One way of correcting oversteer is to turn the wheels in the opposite direction of the slide and power down to effectively accelerate out of the spin. Some drivers such as Sauber's Jean Alesi prefer a car with oversteer as it allows them to adopt a more aggressive driving style. This may be a crowd pleasing tactic but it rarely turns out to be the fastest way around the circuit.
This is the ideal. Basically the sideways drift of the rear wheels is matched by those at the front. All four wheels slide in the same direction. The driver simply sets the car on entry into the corner so the front wheels are straight and he then doesn't have to steer.
Knowing a formula one driver wants the highest speed as possible, it is necessary pick one or more reference points. Most drivers rely on advertising boards or tribunes or anything to indicate their turning and braking points. Though all circuits are provided with 100, 200 and 300 m signs at each corner, very few drivers find these signs enough to know exactly where to do what.
To keep that braking point as late as possible, mechanics have been able during racing history to make the actual cars possible to stop from 100 km/h within 19 metres. Thanks to very efficient brakes, a very light car and broad tyres, a formula one car is unbeatable when it comes out on braking. When the drivers doses this brake force not well, he will block one or more wheels .
Because the racing line on most circuits is so narrow most attempts at passing occur at the end of long straights using one of several available techniques. One of these is called slipstreaming or drafting which has become more and more difficult as cars have made much greater use of aerodynamic aids. In its most basic of forms, drafting involves one car tucking up behind another while running at high speed. The car in front acts as a battering ram pushing through the air which reduces the load on the following car. This allows the engine to work less to achieve the same speed.
This envelope of 'softer' air begins around 20-75 feet behind the lead car. The second car simply tucks up behind him and when the opportunity arises, simply duck out from behind the lead car and take him on the inside.
Instances of drafting in Formula One have reduced in recent years because the advanced aerodynamics of modern cars means that the pocket of 'soft' air is now filled with turbulence created by the rear wings of an open-wheeled lead car. That turbulent air can disrupt the downforce of a trailing car because it does not pass cleanly over the front wings. This means that while trailing drivers may enjoy advantages in horsepower they often suffer from disrupted handling which makes passing difficult.
Out-braking The other common passing method is to out-brake an opponent at the entry to a turn. This involves braking after the other guy with the aim of darting in front of the slower car, thus forcing him off line. If all goes well the 'late-braker' will be able to claim the corner and force the competitor to take a slower line through the turn. Any miscalculation on the part of the pursuing car will push the car to outside of the turn after the apex. That will allow the competitor to retake the lead on exiting the turn and can often result in the pursuing car spinning off the track.
Mostly, the out-braking driver, will try to pass as he is at the inside of the corner. so that is, when a corner bends to the left, he mostly passes at the left of the competitor.
Although, a man that protects his position, may go off his ideal line once. The pursuer is than obliged to, either brake, or either try to pass him from the outside, which is what happens on the picture. David Coulthard tries to pass Schumacher, and because the latter protected his position, he was forced to pass at the outside of the corner. It is there even more crucial to brake very late, because you have that little more distance to go to the apex of the corner, while Schumacher is very close to it, and may block Coulthard to turn in before him. This certain overtaking manoeuvre at Barcelona 2000 was succesful for Coulthard, who took the leading position.