Hugely complex systems, processes and considerations make Formula E an immensely challenging motorsport discipline. We take a closer look at what drivers need to consider.
The ABB FIA Formula E Championship is a fascinating series. I think anyone that’s been involved or driven in Formula E – myself included – has the opinion that it’s the most difficult formula out there. Our speeds may not be as high as other disciplines, but the systems and complexities involved make it a hugely challenging championship. Those outside of the Formula E often struggle to understand this. Combining treaded tyres, tight twisty street tracks, big manufacturers and their heavyweight engineering talent, regeneration and some of the world’s best drivers… it gives you a lot to think about while in the driving seat!
There are many significant differences between Formula E and other forms of motorsport. You need to have a good grasp and experience of them all in order to react correctly to any given situation that arises during a race weekend. Let’s go through a few.
Before getting into Formula E, I competed in a lot of endurance racing events. Yet the only place where I’ve really needed to practice fuel saving was in the IMSA WeatherTech SportsCar Championship in the USA. At some of the series’ longer races the pitstop windows are open, so if you can stretch out your fuel or use less, you can gain an advantage. A ‘splash and dash’ pitstop under caution can help you beat other cars back out onto the track, so using fuel sparingly is a useful skill to have.
However, going into Formula E it has been a whole new world of energy saving! You need to go to great lengths to optimise performance; it has been quite an eye-opener!
My first time driving a Formula E car was at a test ahead of season one. I was driving the car for Autosport and I had no clue about the car nor any information from the engineers, everything was so new. I did two or three runs around Donington then a ‘race run’ of six or seven laps. There was no bleep strategy to help you understand when to coast or regen, you just had to get a feeling for it. The circuit has long straights and high-speed corners, so it was pretty challenging. Although I got my head around it quite quickly, I still overconsumed energy and it’s safe to say that had it been a race, I wouldn’t have made it to the end. The extent to which you need to save energy to get through a Formula E race is totally unique compared to any other form of racing – it makes it a huge but certainly fun challenge.
To optimise energy saving during a race we do a lot of work in the simulator beforehand. The team’s engineers will work out how much of the straights to coast on and how much regen to use going into the corners. How we use regen differs depending on the corners – you need to keep the car stable while recuperating as much energy as possible. We’ll work together on the more difficult corners, which are usually a combined braking zone where you’re trying to slow down the car and turn at the same time. If it’s a particularly bumpy track, that throws in an extra challenge, so we try to make it as easy as possible for the driver to manage.
But it’s not always about recovering the most energy as possible. If you over slow the car then you need to get back on the accelerator and use the energy that you’ve just recuperated. Having a car that’s balanced – light, responsive and flowing through the corners – is really important. You can utilise good car balance to carry you through a corner efficiently while saving a lot of energy, rather than having to brake or accelerate to manipulate the car. We use practice sessions at race weekends to get the balance right, as not only is it attributable to a good qualifying position, it results in good race pace. We will do between six and eight energy laps in FP1 in the early part of the session while the track is dirty, which gives us an idea of how tight the track and corners are, but we won’t do much more energy management until the race.
During a race, situations are continuously coming up where you need to decide whether to use extra energy or save it. If you start near the front and your energy management isn’t great you can still draw out quite good results. But starting further back, even with great energy management, it’s harder to move up the field without overconsuming.
Overtaking is quite a cat-and-mouse game. You need to make the tricky strategy decision of whether the car ahead will accept being overtaken. It’s not purely about speed, so you may decide to use extra energy and accelerate on a straight only for the driver ahead to stop coasting and get back on the accelerator themselves. If you’re going to fight for position, you’re both going to over consume energy.
It’s important not to be overly ambitious and to take a big picture view of the race. In a worst case scenario you may fight for an overtake, lose a chunk of energy and still don’t gain the position. Or, you may get drawn into defending your position and consuming too much energy. Sometimes, if you’re the car ahead, letting one person by is probably better than trying to defend from everyone and ending up in a huge energy deficit. I’ve seen many situations when drivers are having to limp around the last few laps – losing a tonne of places – because of poor energy management. Thankfully we haven’t been in that situation; it means the whole weekend’s work comes to nothing. The energy is there to be used as you wish, and that additional level of strategy makes it really exciting.
During a race weekend we effectively have four levels of power: 110kW for shakedown, 200kW for race pace, 235kW for Attack Mode and 250kW for qualifying and when awarded Fan Boost.
On Saturday morning in FP1 you go out on 200kW, which can feel fast after 110kW in shakedown. We go straight into energy running and also have one lap in each practice session for running the two higher power levels. Having just two laps on 235kW and 250kW power levels doesn’t give you adequate preparation time, especially when you’re running on a circuit that’s changing and you’re still making set up changes. On many occasions there is traffic to contend with, or yellow or red flags may cut your lap short. It’s very rare that you get a clear and perfect preparation lap. You have to improvise and use your gut feeling in the situation, preparing as best you can to find the right braking points ahead of qualifying. It’s certainly tough!
Typically, in other motorsport series, you qualify with low fuel levels and on new tyres, which gives you a weight advantage and a boost in grip. However, in Formula E we have the same level of weight – a fully charged or empty battery weighs the same – and the tyres don’t have a peak performance window when new; they are pretty stable throughout their lifecycle. When you switch to 250kW for qualifying, rather than attacking you have to try and manage your driving quite carefully. You need to pull back your braking points, braking earlier than you would have on the 200kW push laps. That’s a pretty strange dynamic to go out there in pursuit of the fastest lap time, but pulling back and being more careful on the throttle while doing so. With the extra power, it’s really easy to be too aggressive and spin up the wheels, which can overheat very quickly.
It’s such a strange balancing act and unlike any other series I’ve ever driven in. In the race you then run at 200kW, with two four-minute runs of 235kW in Attack Mode. There’s also the option for 250kW during Fan Boost but I’ve not received that to date… hopefully that’s something we can change when racing resumes!
In any series, the most important thing you need to know is how to get the best out of your tyres. Tyres are what keeps you on the racetrack and gives you the grip to propel around it. Formula E uses all-weather treaded tyres. The compound is vastly different to what is typically used in motorsport, whether that’s a dry weather slick or a full wet tyre. In most series, tyres have an optimum temperature window of around 70-95 degrees Celsius, which is when they operate most effectively. We don’t have too much data during a Formula E race weekend, but the operating window of our tyres is a lot lower than that.
When you first head out onto the track the tyres are cold. We don’t have tyre warmers to heat them to a predetermined and optimal temperature. For Super Pole, you get an out lap and then a timed lap, and the tyres are designed to perform under these conditions. However, during that time you can easily go from having cold tyres to overheating them. If you slide a few too many times then you can cook the rear tyres, meaning they begin to lose grip and you can forfeit a lot of time over a lap as a result. In testing, when you do multiple laps, they can overheat substantially. The car can start to squirm underneath you. You need to be a bit more patient and work with the tyre in hot conditions.
In Formula E, we have a standing start. There’s no warm-up lap to get any heat into the tyres. We’ve been on the dummy grid for around half an hour, so if you managed to get any temperature into the tyre on the way there then it would have been lost. Going into a high-pressure race situation where you and all the cars around you have stone cold tyres and stone-cold brakes is unique and a challenge. You can’t replicate that situation and plan for it in testing. You need to be able to work out where the other drivers are around you, choose where to go, while also having to deal with cold tyres, cold brakes and a myriad of other technical considerations.
We use carbon disc brakes, which don’t work so well when they’re cold. They can lock up and be too forceful; they need some temperature in them to provide decent grip. There is a brake-by-wire system on the rear, which calculates how much regeneration is available and how much mechanical braking needs to be introduced to counteract the lack of regen. Regeneration is capped at 250kW and changes relative to your motor speed.
At the start of the race when the car is in a full state of charge, the rear brakes work fully. Then, as charge reduces, regen levels ramp up and the systems reduce the amount of mechanical braking required. Regen only works on the rear axle, but that’s something Formula E is looking to change for the next generation of cars, the Gen3. Bringing in the front brakes will balance out the system and make it a lot more efficient.
Regeneration also influences the rear wheel temperatures. By using mechanical braking at the start of the race the discs could get up to around 600 degrees Celsius; this heat then dissipates into the wheel rim and tyre. As the race goes on and regen covers almost all the braking, you lose that internal heating process. Your rear tyre temperature can drop, or can be lower than the front tyre temperature, which affects the car’s grip and balance.
There are so many things to think about when competing in Formula E, and that’s without even getting started on energy management, coasting, learning how to drive efficiently or learning the bumpy street tracks! These considerations all come into play and make Formula E a hugely complex and challenging series.
I’ll be adding to this blog regularly with further insight into the challenges and complexities of competing in Formula E, so check back soon.