Friday, June 24, 2011

F1 - the season so far

I wrote this post after the Monaco race, but forgot to post it. Well, better late than never...

 

We are now 6 races into the F1 season and we’ve had 6 crackers with lots of overtaking, I cannot remember a time when there was so much happening all at once. Why was overtaking so infrequent in F1? What changed to make such a drastic difference? Here’s my take on it. DISCLAIMER:I don’t profess to be a technical expert, just a passionate fan who has been following F1 for the last 25 years . 

 

Firstly coming to overtaking, I think there are three main reasons for why it was so uncommon in F1

Aerodynamics: The most common method of overtaking in a straight line is slipstreaming. Slipstreaming occurs when the car behind occupies the hole in the air created by the car in front before the space is filled up by the displaced air. Due to the reduced wind resistance, the car behind is able to go faster and overtake. You may well ask why slipstreaming has reduced? When a car moves, the air that it displaces has to go somewhere. The goal of the F1 car designers is to direct the air as they pass through in a way that it presses the car down and gives more grip, thus enabling the car to go through the corner faster. It’s the reverse of aeroplanes where they try to achieve lift. That is why the F1 cars have these big wings in the front and back. The downside of the aerodynamics was that the air that exited the back of the cars was so turbulent that the effectiveness of the aerodynamic design was greatly reduced for the car behind. So, the effectiveness of the wings was reduced and the car could not go as fast and fell behind enough to not be able to slipstream

 

Cornering speeds: In the olden days, the cars would be going 300 kmph on the straight but when they came upon a corner, they would need to reduce the speed to 80-90 kmph to have any chance of making it through the corner safely. Since the tyres and brakes of the day were not that advanced, cars had to brake 50-100 m before the corner and this gave the opportunity for the car behind to delay their braking by 10-15 metres and overtake the car going into the corner. However, with the advance in tyre technology (and aerodynamics), the speed that the car could carry through the corner increased and with the advent of carbon-fibre brakes, the braking distances reduced significantly. As a result, the opportunity to “out-brake” someone into a corner reduced significantly.

 

Strategy: One of the biggest changes in the sport was the advent of Michael Schumacher and the usage of pit-stops as an overtaking mechanism. He figured that since modern technology can make it so difficult to overtake cars on the track, why not pass them in the pits? The strategy involved staying out for a couple of laps after the car in front had pitted and driving to the maximum speed so that when you pitted for new tyres, you would come out ahead. He did this with astonishing success during his heyday. The downside to this was that it was very boring for the average spectator who could not understand the intricacies that went into the overtaking.

 

The FIA has been trying to remedy the situation and put up a good show for the spectators for a while now. In 2010, it banned refueling and made the usage of two tyre compounds mandatory. The hope was that teams would adopt different strategies and we would see cars with varying grip levels on track together, thus promoting overtaking. However, it did not work out as the tyres proved very durable and most teams stuck to one or maximum two pitstops, most of which were in sync with each other. The aerodynamic issues remained as before.

 

So, for 2011, they came up with 3 really bold steps, Drag Reduction system, high wearing tyres specification and KERS. Let’s look at each of them

DRS is the most controversial of the three rule changes. Basically the rear wings on the car are inclined at an angle when viewed from the side so that the air flowing over them presses the car down. This is most useful in the corner. However, in a straight line, the wings create more drag. That is why in circuits like Monza, which is a series of straights, we see the cars with wings that are almost parallel to the ground. DRS basically allows the teams to change the angle of the rear wing on the straight so that the car can go faster. Simple really. But, this is F1 and nothing is as simple. The catch is that DRS is only available if the car is less than a second behind the car in front and only on a specified area of the circuit. So, remember when you could not slipstream because you were falling behind on the corner? With DRS, you now have much lesser drag and can go significantly faster than the car in front and hence can get back into the slipstream and overtake.

 

The importance of aerodynamics had overshadowed the role that tyres played in providing the grip to the car. Historically, tyres have tried to strike a balance between softer rubber compounds that provide more grip but wear out faster and harder ones that last longer but aren’t as fast. The idea behind making the use of different compound tyres was the softer compound With the single tyre supplier rule in effect, Bridgestone had no real pressure to innovate. As a result, their tyres were so durable that 2010 saw many races reduced to a single stop race. In 2011, Pirelli won the contract to supply the teams with tyres and they were given the brief that the tyres had to wear out enough such that there was a marked difference in grip between the hard and soft compounds. In tracks like Spain, the hard compounds were two seconds a lap slower. But the soft compounds would wear out quickly, thus requiring more pit-stops. So, you had an option, lose 20+ seconds in a pit-stop but make up the time at 2 seconds a lap. An added twist was provided when top cars (Webber/China and Heidfeld/Spain) were knocked out in Q1. Since they had not used their soft tyres at all in qualifying, they were able to go much longer on these tyres, thus making it possible to gain enormous amounts of time on the cars in front of them during the closing stages of the race.

 

The least impactful change was the re-introduction of the KERS (Kinetic Energy Recovery System). While braking, the energy is dissipated as heat, KERS allows that to be transformed to electrical energy and stored in a battery. This gives an additional 10% “boost” over the engine power thus enabling the cars to go even faster. KERS can only be used for 6 seconds over a single lap, so the driver must choose the spot carefully.

 

So, what has been the impact of these changes? We’ve had lots of overtaking, some thrilling come from behind drives (Webber from 18th to 3rd in China, Heidfeld from 24th to 8th in Spain) and a huge number of pit-stops. There is so much action that it is impossible to get a complete view just watching it on TV. My usual practice is to have my laptop open with the Live Timing in one window and a twitter feed (where I follow some of the prominent F1 journalists) in another. The live timing gives you wonderful insight especially in the mid-field that rarely gets much coverage. It was fascinating to see the gap from Webber and Heidfeld to the driver in front come down by 2-3 seconds a lap. And just to prove a point that it’s not all about overtaking, we’ve seen Vettel soak up enormous pressure at Turkey and Monaco and still keep it together.

 

With all this excitement, I can barely wait for the next race to come on.

1 comment:

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