Just Electric

New season, new era: A look inside the new Gen2 car

Formula E entered a brave new world last weekend with the introduction of the all-new Spark SRT05e.

After four seasons with the original Gen1 car, the SRT01, the Gen2 Formula E car has already caught the attention of a lot of people with a noticeably sleeker design.

There have also been a large number of changes under the skin with the cars now able to complete a full race distance of 45 minutes plus 1 lap in the same car.

The top speed has increased to 280km/h and the 0-100km/h time has gone down to 2.8 seconds thanks to a combination of more power and softer tyres.

But what impact will all of these changes have?

Battery

The most notable aspect of the powertrain is the new battery, meaning that the car swaps of the first four seasons are now a thing of the past.

The power output has gone up from a maximum of 200kw to 250kw in qualifying with the race power now set at 200kw, up from 180kw last season.

The capacity of the battery has almost doubled from 28Kw/h to 52Kw/h although unrestricted, it can store 54Kw/h; and the battery can also be recharged in 45 minutes thanks to a new system from Enel, who are the Official Smart Charging Partner and Official Power Partner of Formula E

The battery is also slightly heavier than it was last season although this is mainly down to the increase in the number of cells.

The increase in weight has also had a slight impact on the weight distribution of the car as Mahindra Racing’s Garth Harradine explained: “I think you’ll probably find that we are in more or less the same weight distribution. Perhaps a couple of per cent forwards or backwards of where we want to be or where it was.

“But, there are rules which state that you can only have X amount of per cent forwards or rearward, so it’s the same for everybody and its achieving that with the package that you have.”

Another interesting thing about the battery (RESS) is that it is not a fully stressed member, meaning that it isn’t part of the chassis.

As Vinit Patel from Mahindra points out: “The monocoque design is quite unique as the RESS sits entirely within it. The monocoque takes all the chassis loads and is designed to ensure the RESS can be unstressed.”

The battery is a spec component, meaning that it is the same for all of the teams so that costs can be kept down for all of the teams. Had battery technology been opened up, Harradine reckons that the teams would all be trying to increase the all-around performance, but at the cost of the competitiveness that has become a hallmark of the series.

He said: “You’ve got to believe that you want to go as fast as you can for as long as you can, by consuming the least amount of energy, and then battery temperature also sometimes becomes your limiting factor. So, it’s not one particular thing that you’re going to gain and go and win world championships with.

“It’s going to be, the objective is to go faster, with as much energy, with more energy. More energy gives you speed so try to get more energy out of the battery for a longer period of time without overheating the battery. So I think that’s what a lot of people would improve on if they could.

“But fortunately, the most important thing is that it’s not free because if it was free then, there would be teams that would be in another league because they’ve got so much more experience as far as that’s concerned.”

Regarding the battery cooling for this season, Patel reckons it shouldn’t be as much of an issue as it has been in previous seasons adding: “The cooling package design is integrated into the RESS design process and for Gen2, Mclaren have done a great job of making the cooling very efficient.

“We will still need to keep an eye on it but with lessons learned from Gen1 and 4 seasons of racing, the system is quite robust and should be a lower order factor in Season 5 races.”

Software

Another area of development in the series which is even further under the skin of a Formula E car is the software. This is an area which isn’t known about so much but plays a crucial role in the optimisation of the package in general.

At this stage of the season, everyone is still trying to optimise everything for a stable baseline setup and there are gains which can be made in this area. As Harradine explains: “Once you’ve got your hardware more or less sorted, you’re totally dependent on the software and the development thereof.

“So, these guys don’t sleep at night and our engineering group, as far as that’s concerned, grows by the day too. There’s just not enough hours in the day, not enough people and not enough hours in the day to write code, to try to practice, to simulate it, rewrite it, change it. It’s an exponential graph or curve as far as development is concerned.

“And, you find that once the year begins too, people think, oh well, that’s sorted - but you can always improve on it.”

Brake-by-wire

Another key introduction for this season has been brake-by-wire.

The way a traditional braking system works is that one would push the brake pedal and in turn, that would push fluid at a high pressure down the brake lines and into the pistons in the brake calliper which then push the brake pads against the discs.

As Patel mentioned, there are a number of differences, especially towards the rear of the car saying: “The brake-by-wire system still uses a fully hydraulic line, as you described, to operate the front brakes. However, the system uses a control unit alongside our customized software to deliver a mix of hydraulic braking power and regen braking power to the rear axle.

“We are free to determine the mix of regen and hydraulic which allows us to optimise performance in qualifying and energy recovery in races.”

He also mentioned that it also makes setting the car up easier adding: “It’s another tool which allows us to fine tune and customise the car to specific driver needs, circuit demands and importantly manage energy. It’s a benefit compared to the Gen1 car and is a system that will directly transfer to road car technology so is very relevant to the real world EV systems so makes sense we develop it for racing applications.”

Audi’s Lucas di Grassi is one of the few drivers with prior experience of brake by wire systems from his time driving for the manufacturer in the World Endurance Championship.

He points out that there is a lot of correlation between the two systems - although the driver doesn’t have any scope for developing the system - saying: "It’s the same system basically. But at Le Mans, it was shifting the front because we had the electric motor at the front and the combustion at the rear so it was shifting the regen to the front.

“Here, it shifts the regen to the rear but it’s the same system, the same base algorithm that controls the brake system - but the driver does not really develop anything. You can do the settings, I need more brake to the rear, more brake to the front, I need more this, more that.

“But, the development of the system is done on the dyno, the driver has zero input.”

Halo

One of the most notable aspects about the Gen2 car is the addition of the halo above the driver. This has been added as the result of an FIA mandate which has seen the halo added to the new cars in Formula 2 and Formula 3.

The structure is built out of titanium, just like the ones used in Formula 1 are and despite only weighing 7kg, are capable of taking a force of 12 tonnes. 

As a result of this, as Patel explains, the centre of gravity (CoG) is not that much different compared to the old car, saying: “The CoG pre-halo is pretty similar to the Gen1 car, which was a nice surprise considering the very different RESS, monocoque and car layout.

“We have not been able to assess the Halo effect fully as we tested with it from the word go and it's of no interest to do any learning without it. Our simulation tools told us at an early stage when it was announced that the impact on the macro metrics of the car affecting car balance and tyre usage etc, it’s a very small effect.”

From a driver's standpoint, it is interesting to hear what they think about the halo and if it has much impact on visibility from inside the car. However, there doesn’t appear to be any difference at all according to Audi’s Daniel Abt.

He said: “For me, zero difference! Honestly, there’s been so much about the halo, I think its stopped already because it's always the same process. Something new comes in, everyone complains, one season of Formula 1 and I think people don’t even realise that it’s on there.

“And for the driver, it makes no difference apart from the fact that you have a safety tool. So, I think there was a lot of discussion for nothing. For me, it’s fine to have it, if it saves me in a situation, I’m happy and I can still see where I’m going.”

Aerodynamics

The new aerodynamics of the Gen 2 car have also been a big talking point.

The low and sleek design, the large rear diffuser, the Ferrari FXX style winglets mounted over the rear wheels and the completely covered front wheels. In the eyes of many, the car is seen as good looking and it seems as if there is a good balance of function and form, as Lucas di Grassi explains.

He said: “These cars, they have very efficient aerodynamics so the car is more efficient, the less air we drag but the downforce is similar. So, the main point is that you don’t lose so much downforce behind.

“This car doesn't have so much downforce anyway, that’s why you see us sliding everywhere. So the concept is that you don’t add downforce to the car; if you add downforce, if you are behind another car, you’re going to lose it.

“So that’s what happened in F1 with the wider car, that’s what happened in LMP, you cannot follow another car because you just lose all the aerodynamics, even from far away so, with this car, we can be very close. There is no problem with that.”

The size of some of the powertrain components like the inverter are smaller again this year as the technology has matured and as the engineers and designers find different ways of implementing everything.

Harradine thinks the step changes per year depend on what has become available, as to whether it’s an incremental change or a larger change saying: “It depends really on what the designers can come up with and what they’ve learnt from the previous to the next year.

“Some of the stuff is on the limit so you wouldn’t think that they’d be able to go any smaller or lighter, that kind of thing. And even in testing, maybe we’ve realised like you always do, we’ve overstepped the mark and we’ve had to come back a little bit.

“But then there’d be other things that also through innovation or new products come onto the market and you’re thinking, you know what? We can make a big step as far as that particular part is concerned.

“So, it just depends on, more or less, how much you’ve learnt from the year before. Like I say, how many new parts or how many new components might be on the market and, obviously now too with it being a new generation of car, the first year is always going to be your learning year.

"Every year’s a learning year but especially the first year and then from there onwards, we’ll learn by our mistakes this year and we’ll make it better for next year and next year we’ll learn by our mistakes from next year and we’ll make it better for season seven or eight.”

Bodywork

One area which hasn’t been made smaller is the bodywork. Walking past the garages at pre-season testing in Valencia, the size of the bodywork components was notable, especially the nose cone, front wing and fenders.

As Patel explained, the increased size is going to make life for the mechanics a bit harder saying: “The car is now harder to work on than the Gen1 car, but our mechanics are working on new processes and practices to ensure any pitstops or changes of noses etc can be done as fast as possible.”

He also thought that there is a chance that we could see teams and drivers getting through a few of the front clips over the course of a season, adding: “Formula E has always been close racing, and we’ve regularly seen brushes with the wall and other cars through the first 4 seasons.

“The Gen2 car has more bodywork of different shapes at all its extremities, so we are likely to see a reasonable amount of bodywork repairs this year.”

Tyres

Michelin have also brought a new type of tyre to the series for this season. The chemical compound of the tyre is softer and they are slightly lighter now as well.

Harradine thinks that the impact this will have over a race distance is going to be negligible and think that the tyres won't be the limiting factor saying: “I think at the end of the day, Michelin are very experienced and they’re not stupid and they’ll change it accordingly but it’s also up to the team to make sure that their tyres last.

“So, your setup, obviously, becomes really important and I think you’ll find that tyres are not going to be your limiting factor. I think it’s going to be your energy management and battery temperature I think.”

Mechanics

Finally, with all of the differences which are being brought in by the introduction of the new car, there will, of course, be a plethora of differences for the mechanics.

Whether these differences will make life easier or otherwise for the mechanics in the heat of battle is unknown as of yet, but Patel reckons that the mechanics will be focused on just fixing the car saying: “Easier isn’t really a consideration we care about, we just tackle the job in hand.

“The car design by and large is given to us except the powertrain and rear suspension, so we work to optimise the package and this job is about being efficient, optimising performance, and out developing our rivals.

"Easy is not a word we care about!”

--

So how has the new car fared after the opening race?

Well, due to the inclement weather on the morning of the race which played havoc with the schedule, it may still be a little bit too early to tell how the car reacts over a full-on, 250kw lap in qualifying. 

However, the racing was still as close as it always has been and the drivers were able to follow each other without losing much downforce. 

As the checkered flag fell in Ad Diriyah, one thing which can be guaranteed is that the brave new world isn't the future, it's the present!

 

Rob Lomas

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