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Tech Spec
Will Davies

Since before he can remember Will^ has watched F1 – he would always be sat down to watch the start before going out and continuing to follow on the radio. His first F1 memory is of his parents snoozing to what they considered the soporific tones of Murray Walker. Having lost touch somewhat during the years at university, Will^ has now reconnected with the sport and is a bigger fan than ever; often combining his interest for the more technical aspects with his love for maths for some 'interesting' results.

Must-have gadgets must have acronyms // An overview of driver tools to aid overtaking

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During recent times F1 has seen the introduction of various overtaking aids for drivers to compliment their driving and perhaps enhance the racing in the process. First we had the KERS button which, like previous (and now future) turbo engines, could deliver a boost. Then was added the DRS system, which was a different method of improving a cars’ straight line speed, and now that has morphed somewhat and spawned the DRD.

KERS - The boost button

Back in 2009 F1 saw the introduction of a new set of initials for everyone to get their heads around. The Kinetic Energy Recovery System was designed to recycle surplus energy from braking and to reuse it as a short boost, primarily for use with overtaking - either helping the driver perform a manoeuvre or helping him defend against one, and thus this incarnation of the boost button was born.

Without getting into the actual mechanics, KERS essentially stores energy from the rear axle under braking in a battery, which can then be converted back into a boost in power at the press of a button on the steering wheel.

F1 KERS in action
Credit: Williams F1

If you want to delve into the technical; the system utilises a generator that is connected to the rear axle, so that under braking it takes some of the load, harvests the kinetic energy and converts that into electrical energy (much like a bicycle light that is powered by a dynamo). This energy is stored in a capacitor (which can be thought of as a battery that can be discharged at a much faster rate).

When the driver presses their KERS button the stored electrical energy is fed back into the generator unit (which when running the opposite way round is now functioning as a motor) which will increase the RPM of the axle, delivering more power to the road and increasing the speed or rate of acceleration of the car for a short length of time.

Drivers are able to adjust the ‘harvest-rate’ from their steering wheel so as to dictate percentage-wise how much energy is converted during braking versus how much of the work the brakes do. This is in order to manage the balance of their car and prevent their wheels from locking.

Also permitted under the KERS rules is the possibility for a mechanical solution, where the energy is stored using a flywheel, but no team in F1 runs it – most likely for weight reasons. It can however be seen in use on cars competing (for example) at Le Mans.

It is known for drivers to use their KERS to defend from being overtaken as well as to gain an acceleration or speed advantage during an overtake – using it out of slow corners or before long straights will maximise the top speed a car might reach or allow it to reach that speed sooner down the straight. It has been used similarly by a defending driver to get as far away from their attacker, or break the DRS-gap. There is currently a maximum of 6.7s of KERS that can be used per lap, and in qualifying most drivers will use the whole push on their run to the line only to have it recharged for use again on their flying lap – getting as much from their system and as much of an advantage as possible.

One of my favourite F1 overtakes came in the 2009 Belgium Grand Prix at Spa. Kimi Räikkönen (in his Ferrari) uses a huge push of KERS to overtake Giancarlo Fisichella (in his Force India) as they reach the top of Eau Rouge after the safety car restart, especially because the coverage was watching it unfold from onboard Kimi’s car. Despite the teams agreeing not to run the system in 2010 for financial reasons something changed, it was reintroduced in 2011 and ever since teams have not looked back.

But with great power comes great responsibility, or more accurately in this case great risk. The amount of electrical energy that is stored in the capacitors can be extremely dangerous.

Warning sign, Williams garage, China
Credit: Dunbar/LAT

The batteries can overheat and cause electrical fires, or a short-circuit can render the whole car live which threatens to deliver a rather large and distinctly unhealthy electric shock. This is why you will see mechanics wearing marigolds (the rubber insulates the wearer) when there is the possibility of a KERS failure.

The biggest example of a KERS incident was the catastrophic scene that followed the 2012 Spanish GP. When Bruno Senna’s car discharged at an inopportune point during break down and pack up it discharged in the vicinity of fuel systems which were ignited, causing a large fire with much acrid and billowing black smoke. Luckily no one was severely hurt, and teams all thought through their KERS procedures so that they could all avoid future similar severe occurrences.

In 2014 the power capacity of the KERS storage is due to increase from 60kW to 120kW, which will effectively double the length of time that the boost is available to just over 13s per lap, so we can expect twice the amount of action coming from this area!

DRS - The moveable rear wing

With the reintroduction of KERS in 2011 also came the introduction of the Drag Reduction System, with the purpose of increasing the possibilities and ease of overtaking. It functions by altering the angle of attack of the uppermost plane of the rear wing through the use of hydraulics mounded centrally or in the end plates. Reducing the wing-angle to almost-zero decreases the drag that the wing is generating allowing an increase in speed. Operating the DRS enables a car to gain an extra few mph, which on top of a good tow, can make the difference when trying to make an overtake stick.

It’s not as simple as drivers just opening their DRS willy-or-indeed-nilly, i.e. wherever they chose or whenever the run up behind another car. During the race there are specific zone(s) where operation is allowed. The pursuing driver has to be within one second of the driver ahead when he passes the detection line (usually a corner or two before the zone begins). They’re usually placed on the longest straight(s) on the circuit, if it has one and some circuits sport 2 zones can either have 1 or 2 detection points meaning that drivers get a double chance to overtake back-to-back, or 2 chances in one lap.

When the car reaches the activation line the DRS becomes available and when the driver presses the button on their steering wheel the hydraulics opens the flap. It remains open until the driver then presses the button again or touches the brakes. It is worth noting that the flap will not close if a driver comes off the throttle – it is possible for a car to pass through a yellow flag zone with the DRS flap open despite having backed off as is required in the rules. Jenson Button is just one of a handful of drivers who have had occurrences of this looked over by the stewards in races this season; all received no sanction. So if you see a banner on the screen telling you your favourite driver has been supposedly misusing his movable rear wing in a caution zone, it is most likely he has not been, especially if the telemetry bug resurfaces.

Ricciardo with DRS fully open
Credit: Getty

As well as reducing the amount of drag the rear wing generates, the DRS also works by reducing both the downforce and although this is also useful, the FIA considers there to be places on a couple of circuits on the calendar where this is not appropriate. When the DRS was introduced in 2011 its use was unrestricted in the practice sessions and in qualifying, but it was considered too dangerous to be used through the tunnel in Monaco as well as up the hill through Eau Rouge at Spa Francorchamps. This regulation is now somewhat moot as the reliance on DRS for fast laps was deemed too much and as of 2013 in practice and qualifying the movable rear wing is only allowed to be activated in the same zones as are used for the race.

One major downside to cars carrying and using this piece of kit is that it adds an extra level of complexity and another opportunity for things to break. At the 2012 Canadian GP we saw problems with the Mercedes system when Schumacher’s DRS was locked open as the hydraulics system had jammed. Back in the pits for the second time, four maybe five mechanics were seen putting all of their weight on it trying to close the flap but to no avail and the only option was to retire the car.

More recently at the 2013 Bahrain GP Fernando Alonso suffered a similar fate; his flap got stuck open but this time it was possible for it to be closed by hand in the pits. Believing this to be a one-off on the next lap he activated his DRS and suffered the same fate. These problems cost Fernando his chance of fighting for the decent point-scoring positions but he did manage to claw himself to an eighth place finish.

If this DRS problem happened in the last part of the race maybe with another stop you lose two or three positions, but when it happens in the first part of the race, you lose 18-20 positions, and it become more difficult to fight with no DRS. We tried to save some points but it was a little bit unlucky race.

- Fernando Alonso, F1 driver, Ferrari

DRS is great when it works, but can be a race-killer if things go wrong.

DRS has its detractors as if the activation zone is too long then at the end of the straight it can sometimes feel that overtakes are made too easy. If it’s a choice between ‘easy’ overtakes or none whatsoever, then we all know the answer. All it takes to perfect is some thought in order to get the length of the zone such that the overtaking driver is alongside as they reach the braking zone – to bring back some of the traditional late-braking challenge. At the end of the day it is here to stay so let’s get behind it.

DRD - One of the many gadgets nicknamed double DRS

One additional gadget that could fall into the category of an overtaking aid is the Drag Reduction Device (DRD). Despite it not being something driver-operated like the previous two, having it on your car would definitely give you an advantage in the race along long straights (as well as in qualifying) – that is if teams can perfect its operation.

Last season the DRD was referred to as the DDRS (or similar) but has now assumed its new name as it is clear that it has no connection with DRS (especially as secondary functions are now banned).

This system would be hard to fine tune so that it switches on at the right speed

The details of the DRD were covered in an article around the time that Lotus first trialled their system last season and these haven’t changed. A few teams have been seen with DRD-bodywork on their cars during various testing sessions, Lotus, Sauber, Mercedes and RedBull come to mind, but no one has tried to race with it yet, and sightings have become more and more infrequent. This system would be hard to fine tune so that it switches on at the right speed, and this work would have to be done on each circuit. It seems teams are prioritising set-up of the cars to ensure best use of the tyres – the part of the car that is working for the whole lap, rather than at select points down the straights. Points for effort, but it seems the DRD is not a vital part of this year’s cars after all.

I think it is fair to say that the FIA have made solid choices with the introduction of these overtaking aids, because with the abolition of in-race refuelling, some of the races were devoid of much action. After the recent seasons, and close racing that we’ve seen, it is pretty clear that this has been more than compensated for. The people who avoid F1 because they think it is boring and processional don’t know what they’re missing! And the action can only get better: bigger KERS, DRS, maybe a DRD or two, and with the advent of turbo engines next season is a must-watch.