Motorsports is changing. The electrification of racing is becoming a reality with the success of the Formula E worldwide electric racing series, Volkswagen’s stunning victory with an electric racer at the Pikes Peak International Hill Climb, and an announcement that electric cars will be competing for the World Rallycross Championship in 2020.
In 2024, the Le Mans 24 hour race in France will introduce a racing class for electric vehicles powered by hydrogen fuel cells. Companies like BMW and Audi have already expressed interest. The push to electric racing cars has some wondering what opportunities electrification might present. One such person is Nic Perrin.
|Nic Perrin worked in Formula One as a track engineer and aerodynamicist and is now heading up a project to bring an electric racer to Le Mans. (Image source: Project 424)|
An Electric Effort
“Project 424 is about going to Le Mans 24 hours with an electric car,” said Perrin, a Formula One track engineer and aerodynamicist who founded the project. “It started a while ago, when I left Formula One to start a project with a Le Mans prototype (LMP1) which, at the time, was a petrol-hybrid engine. The LMP1 we couldn’t sell because the market conditions were difficult,” Perrin told Design News.
“The development of the electric drivetrain made sense—shifting our attention to electric in order to lead the way by going to Le Mans with an electric car. That’s the focus, Le Mans 24 hours,” he said. The project name simply enough comes from “a project for (4) the Le mans 24 hour (24)”—Project 424.
“It is based upon the LMP1 that we developed. Basically, we took the LMP1 and converted it to electric. We designed it to integrate the electric drivetrain,” said Perrin. “We looked around and, basically, what makes the most sense is to use the Formula E motors and inverters that we can get off-the-shelf from a number of companies.”
“We are going to use two motors at the rear, and one motor at the front. The motors are 250 kilowatts each,” he said. “The batteries are going to be off-the-shelf prismatic (lithium ion) cells that we are integrating ourselves into our own module system design. Then the modules are integrated into the main composite chassis of the car. All the integration is done by us.”
Perrin chose the prismatic cells over cylindrical cells based upon his experience in other projects. “I have experience with prismatic cells on a previous project that I have done, and that was successful. It looks like prismatic is used in motorsport more than cylindrical. In my view, they are easier to integrate into the sort of modules that we are building for racing cars. We’ll have nine modules, and they will be bolted directly onto the floor part of the structure, which is them bolted onto the chassis,” he said.
Gaining Publicity for Project 424
With 2024 and Le Mans a long way into the future, Perrin has come up with a way to gain experience and publicity for Project 424. “The project is in two phases. The first is not about going to Le Mans with the car—it’s about running that car as fast as we can for a short period of time to beat electric car records around Formula One tracks,” he told us. “This will be a showcase of the performance of the car, which will be in line with the current LMP1 petrol (racers). That will be the first stage, and it will be important to us because we can show that we can be as fast as petrol-hybrid cars. The second stage will be to go to Le Mans, but that will not be before 2024, when new rules are coming into place for electric cars. At this stage, the energy storage will have evolved—it will be either battery or hydrogen fuel cells,” he said.
Although hydrogen fuel cells may be in the car’s future, there are no development plans for that technology at present. “We are staying on battery right now and it (success at Le Mans) will depend on how fast we can recharge the battery. Effectively, the batteries will always be incorporated into the car. We don’t have a plan for and we will not do interchangeable batteries which, for me, is not the right way to go. It is not a good solution for racing, anyway,” he said.
|CFD analyses of the aerodynamics of Project 424 were undertaken using the SimScale cloud computing CFD application. (Image source: Project 424)|
What about some of the techniques used on electric road cars to conserve energy? “Really, the problem of energy consumption in racing races doesn’t go hand-in-hand. You are trying to go as fast as possible and you are going to use a lot of energy. We are developing the car for speed,” he said.
What about regenerative braking? “We will use regenerative braking, but first of all (in racing), regenerative under braking is not significant. The energy you get back is probably around 5% of what you use in a lap. Braking zones (on a racetrack) are so short compared to straights. For lap records, we might not use regenerative (braking) at all because it unsettles the car a little bit and for gaining 5% energy, it’s not worth it. At Le Mans, yes, we will use it. But at 5%, you will not solve the energy issue and we need to find a way to recharge the battery quick enough,” said Perrin.
Aerodynamics is obviously a key part of the racing car project. “Optimization of drag and downforce in a race car is something that you always do. The LMP1 that we are basing this car on has gone through a very extensive aerodynamic test program in CFD (computational fluid dynamics)—it’s something that you have to do to make sure that the car performance will be as high as it can. So the optimization process of drag and downforce has been done. Again, we have performance in mind, so we will not degrade the performance of the car for the range of the car. The main aim is performance and speed around one lap and for this, you have to decouple the energy problem with the aerodynamic problem. What you do is build the car with the aerodynamics that are required for it to be as fast as possible. I expect it will have more drag than you would want for energy consumption, but that’s what you do. Having said that, we are putting a DRS (Drag Reduction System) on the car to reduce the drag in a straight line and which is something that we think will be allowed at Le Mans. It is interesting to have a system like this, just to gain a bit more performance,” Perrin told us.