Formula E enters a new era with its Gen2 car, and one aspect of the technology changes is causing unease among drivers and teams ahead of pre-season testing. Is FE about to become too easy?
One of the hallmarks of Formula E action during its Gen1 era was the challenge the cars presented to the drivers.
Heavy machinery, low-downforce levels, part-treaded/part-grooved all-weather tyres and sensitive brakes. Plus brake biases had to be finessed continuously as battery temperatures fluctuated and regenerative braking systems kicked in. All of that needed to be managed on bumpy low-grip street circuits closely lined with walls. That's a lot of things to go wrong.
Mistakes were common up and down the grid, which added to the unpredictability FE trades on.
For the 2018/19 season, the start of FE's Gen2 era, adding an aggressively-styled but chunkier-looking car to the narrow confines of city-centre racing might seem like adding even spicier ingredients to the recipe. But the new cars have technological features - common in electric road cars - that may eliminate some of the stress.
One of the main new additions to the Gen2 car is the brake-by-wire system that has been fitted to the rear of the car. With braking electronically controlled at the rear, the cars should be easier to manage, particularly with less need to continuously switch brake bias settings to battle battery temperatures or to adapt to different corners - or so the theory goes.
At the New York season four finale, which took place after the initial private manufacturer Gen2 testing programmes had kicked off, there was a slight air of pessimism suggesting that FE racing was about to change - and not for the better.
"It will make things less driver relevant," said Audi's Lucas di Grassi. "It's part of the evolution, we have to find other ways to make the show better."
Andretti BMW driver Antonio Felix da Costa also warned that "we have to find a way to make races really entertaining next year", explaining that he felt this way because "the car will be easier to drive".
With another of its racing hallmarks - the mid-race car swaps - gone for season five thanks to the greater range of the Gen2 car's battery, FE has had to take steps to ensure the action will remain interesting.
The system formerly known as Hyperboost, now more forcefully called 'attack mode', is intended keep the flavour in the action by shaking up the power modes drivers can run in at certain times of the race, which are activated by running over Mario Kart-style zones at special parts of the track.
A "full test of all the systems" is due to take place at official pre-season testing in Valencia, which gets under way on Tuesday, according to FE CEO Alejandro Agag.
Photo by: BMW AG
But the feedback from many drivers coming out of FE's season five launch period in recent weeks suggested that the complexities of the brake-by-wire systems means mistake-heavy races, and the entertainment they add to the spectacle, may not be about to disappear completely - as might have been feared.
"It's not hard for us, it's hard for the engineers," explains reigning champion Jean-Eric Vergne. "Except with our feedback and what we want, it's up to the engineers that do the software to give us the best system so that the brake-by-wire becomes invisible to us.
"Obviously on the day if there is a problem in the system, and you end up locking massively the rears or massively the front - you might end up in the wall."
There are a few different reasons that the drivers might struggle with brake-by-wire - at least in the early days of Gen2 racing. The chassis and aerodynamics may be locked down by the regulations, as will the various powertrain approaches once they have been homologated by the FIA, but the software needed to run the cars is open for development throughout the year.
So, while any teething problems may eventually be ironed out by the mighty factories that now compete for FE glory, the squads that conquer the issues early and are able to adapt their systems best from track to track are likely to find time under braking.
"Hopefully we get on top of it before others," says DS Techeetah team boss Mark Preston. "I'm sure there will be discussions over a race weekend as to whether people have got on top of brake-by-wire at a different circuit. It's another big parameter to get optimised - especially over one-day racing."
When the lights go out at the start of the races in the coming season, it has been suggested that drivers won't have their regen systems - which slow the car down under braking when activated - available. This means the brake-by-wire electronics will have to balance optimum braking at the rear of the car with the conventional systems at the front end, and then adapt further as the energy harvesting systems become active once the cars are fully up to speed. The complexities of this arrangement, explains Vergne, are among the issues seen in private testing.
Daniel Abt, Audi Sport ABT Schaeffler Audi e-tron FE05
Photo by: Audi Communications Motorsport
"If you have some sensor issues or whatever the system might understand something wrong and maybe the complete wrong braking system and you might end up going straight," he says. "And some drivers have had that during testing, from what I've heard. So we'll see how it goes in the first race."
Another issue for the active braking systems to navigate is physical variations in the hardware they are operating. For the Gen2 car, chassis-builder Spark selected Brembo as the sole brake supplier, and this means the whole mechanical braking system - including the rotors and carbon pads. The problem is not with the quality of equipment supplied but the temperature-sensitive nature of carbon brakes.
"In the car, you can't do much - if the brake-by-wire is wrong, it's wrong and you're going to crash and you can do nothing," explains recently announced NIO driver Tom Dillmann.
"Miscalculations - it's very tricky because we have carbon brakes. With carbon brakes to know the exact friction they have at a set temperature is very difficult. They are also very unpredictable - it's not like you have this amount of friction or this amount of temperature - it's always moving and then you have a brake that is hotter than the other one on the other side.
"The regen is very predictable - you know how much it's going to slow the car. But the braking, with the carbon brakes, as it's influenced by the temperature of them, there is some variety. The problem is that you go out on track , it's all good, you stop and then go to qualifying, and then there is one capricious brake. It's very unpredictable unfortunately."
Since the braking systems are locked into the axles, it's not possible to adjust things to warm up a suddenly underperforming brake on one side.
"It will be when it is one motor per wheel," says Dillmann. But all-wheel drive - which Lucas di Grassi recently proposed in his Autosport Engineering column should be adopted for FE's Gen3 cars - is something the championship organiser is known to be vehemently against at this stage. This is because it would only further increase the technology levels in the cars and would likely militate against the driver making a difference in performance.
FE wants to keep its unpredictable nature. And since the technology many people expected to reduce that characteristic is seems to be throwing up problems in the early stages of its development, those fears may yet prove unfounded.
"You've seen races - everyone's locking tyres all the time," says Jaguar racer and inaugural FE drivers' champion Nelson Piquet Jr. "I think you're going to see it even more this year because the brakes are a little bit more inconsistent.
"Whenever you put carbon brakes and have no grip, no downforce and don't have slick tyres, it's very difficult to generate temperature into the brakes. When you manage to generate temperature you have a gap of 50 degrees , something like this, you're going to start locking one side or the other.
"That's something that we're learning - we're going to end up getting around it but you're going to see a lot of people struggling in this matter, I would say."
DS Techeetah DS E-TENSE FE19
Photo by: Techeetah
As is so often the way in motorsport, and particularly with major manufacturers involved, the teams are likely to get on top of the brake-by-wire teething problems. Once drivers are able to push consistently with full confidence in the braking systems, things will settle down.
But FE's unique setting could still help it retain unpredictability through driver errors.
"It's going to be the same," says Vergne when it comes to the number of mistakes and lock-ups FE races are likely to produce in the 2018/19 season. "Because even if braking is easier, therefore we're going to push more to the limits on the braking.
"We're always going to fight with the limits - either we are at low speed and fighting limits or high speed, always trying to find 100%. And when you try to hit the limit, then you might make mistakes.
"I'm not a big fan of brake-by-wire. I don't mind it, I'm not against, I'm not for it. But what I really like about Formula E is it's a championship for the drivers and now with the brake-by-wire they give an opportunity to the engineers to make the difference.
"That's what Formula E should really try to keep - that it's not the engineer that makes the difference, but the driver inside the car."
Active braking and regen systems are an integral part of electric road car technology - "It's probably important to have it in order to show the technology for the road," says Preston - so their use in FE makes sense. The problem is keeping the balance between entertaining racing and engineering-driven excellence that makes things predictable.
The teams have already begun exploring the limits of their new packages against each other for the first time in official testing on Tuesday. Getting the brake-by-wire systems optimised will be an integral part of their programmes, but the early development issues they have already demonstrated suggests smoke-filled lock-ups, spectacular errors and unpredictable racing isn't off the FE agenda at this stage.