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.
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.