The Formula E driving challenge turned engineering task

Formula E is about to enter a new era with its Gen2 car, but with it will come the loss of a driving challenge totally unique to the series.

One of the biggest misconceptions about the all-electric single seater series is that the cars are easy to drive because of its speed, or lack thereof. Although the first generation car was on similar pace to Formula 3 around Donington Park, its lack of pace compared to Formula 1 for example has made it appear to be easy.

But this could not be further from the truth. Not only does the instant torque of an electric motor make things difficult to begin with, it’s lack of aerodynamic downforce and road-relevant tyres making for a lack of mechanical grip creates a whole new challenge.

This does not compare, however, to the art of regenerating a battery in a racing situation – the thing that every newcomer to Formula E has initially struggled with.

A Formula E driver must manage how much regen is happening throughout a race, and it will change with every lap as the remaining energy level of the battery decreases throughout a stint. This means constant changes of the brake balance, and the driver having an inconsistent feeling through their left foot every lap.

This is made all the more difficult by the thermal degradation of the battery, made by Williams Advanced Engineering. Therefore the temperature must also be managed as regening too much will cause it to overheat, lose performance and ultimately fail.

“One really cool thing about the Generation 1 car is actually how hard it is to manage the temperatures, the braking,” explained Andretti’s Antonio Felix da Costa.

“When you start the race the regen isn’t coming in, because you cannot charge something that is already full, so you don’t have all the regen and your brakes are changing every lap, every corner in fact.

“That’s why you see so many mistakes, and that I think makes the races interesting.”

While the Gen2 car boasts more downforce and an increase to 250kW of qualifying power (up from the previous 200kW), the introduction of brake-by-wire will see this issue massively reduced.

The new braking systems will be capable of working out how much regen is needed and what brake balance is required, while retaining a consistent feeling on the pedal for the driver.

The new battery, from McLaren Applied Technologies which is capable of completing whole race distances, does not suffer thermal degradation to within an inch of what was previously handled. All in all, this will make the driving element of Formula E a lot easier.

“Next year with the brake-by-wire systems that’s all a lot easier to manage, so a little bit of that excitement and the mistakes we sometimes see from our side will be easier to manage and there’ll be less of them,” da Costa added.


Felipe Massa, who will be making his Formula E debut with Venturi next season, said he felt the brakes were one of the most improved areas when asked to compare his Gen2 run with the Jaguar he tested in 2016.

“The big difference I felt was in the brakes. Having the brake-by-wire is a lot better. It understands the balance between front and rear a lot more, so that for me was a big step,” he told FormulaSpy.

“Definitely the brakes are more intelligent. At the moment they have a lot of problems with the temperature in the battery, they need to move a lot of brake balance to the front because the battery’s too hot and then it gets colder towards the end so they need to get the balance back.”

It is fair to say that the braking now comes under an engineering challenge, rather than a driving one, as the team’s will have to optimise their brake-by-wire systems in order for it to be fully utilised.

This is no mean feat. When the hybrid power units were introduced into F1 in 2014, one of the biggest challenges was the new braking system. When Haas arrived in 2016, it took the team almost two years to finally get on top of the system.

The effect of this could mean a slightly split field in the early days of the Gen2 cars as teams find their feet with the new system.

It will not be dissimilar to when powertrain design was initially introduced in season two, when everyone went their own ways but most teams have converged on a similar design come the end of this current era.

But with more effective braking, and regeneration going up to 250kW from next season, tyre wear could start to factor into races, especially as Michelin’s new tyre for the 2018/19 season will be a softer compound than previous generations.

“The fact that we have to do so much coasting now gives us less headache when it comes to the tyres, because the more coasting you do, the more you operate the tyres in the right window,” Felix Rosenqvist told Formula Spy.

“We don’t really have tyre deg here, but I think on the new car when you start having less coasting and always punishing the tyre, accelerating and regening, there’s more going on for the rear tyres and there will be more of a gain of tyres in the picture compared to what it is now. Things will get more complicated for sure.”

Less coasting and softer tyres will also be combined with less cooling, as more of the bodywork is closed, and an extra 20kg of weight with the new battery.

Mitch Evans cited an usual issue for single seater racing which is not seeing the front wheels, as they are now covered by arches similar to a tin top.

“Visually it’s a bit different, not so much with the halo but with the wheel arches, it actually limits the visibility a lot which I was not expecting to just jump in and they have an affect,” he said following his first run in the Gen2 car.

“I think on a street circuit it’s going to be a bit more challenging, and obviously the races are going to be tough because the car’s a bit more bulky. In terms of dimension it’s not that much bigger but I think it looks that way.”

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Chris Stevens

Chris is a member of the Autosport Academy and has been writing about motorsport professionally since 2015. He has been one of the top Formula E journalists since he went to Donington Park for pre-season testing a week after picking up his A-Level results.

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