Why Electric Rallycross makes sense
IMG together with STARD have formed a new ‘electric development series’ called Projekt E which will race alongside World RX in 2020. But why should rallycross go electric?
Why is rallycross suited to electric?
From an engineering point of view, rallycross is the most suitable category to race electric powertrains and this is due to several reasons:
1) The start
In World RX, races kick off with a five-wide sprint to the first corner. Current World RX Supercars accelerate from 0-60mph in 1.9s, which is faster than today’s F1 cars. This is down to a 2.0L turbocharged engine producing 600bhp and 900Nm of torque.
Maximising this acceleration phase of the race is essential because the twisty tracks can make overtaking difficult. Therefore, drivers need high power and instantaneous torque when they launch off the start line – both of which can be provided by high-spec motors.
2) Race profile
The World RX races are short sprints around 1-1.4km twisty circuits, once again requiring high power and instant torque throughout the race. The weekend format features several four lap qualifying races, followed by a six lap semi-final and then final. This means that the battery does not have to last long and it can be recharged or changed in between races.
1) Track surface
World RX tracks are split into roughly 2/3rds asphalt and 1/3rd dirt. As the dirt surface is often gravel or dust, it is effectively a ‘loose’ surface and so the grip level changes with every wheel that drives over it. This is why World RX cars utilise a soft set-up so that the drivers can sense the changing grip levels and adjust their braking and acceleration accordingly.
This continuously changing surface does present challenges for the electric powertrain. Trying to allocate the precise amount of torque to each wheel, when the demands are continuously changing is extremely difficult and will require innovative control strategies. Further challenges lie in developing a KERS system which can achieve this whilst providing the driver with predictive feedback through the brake pedal.
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Moving away from the technical side, introducing a new form of racing comes with a whole host of off-track challenges. Firstly, there are the fans, who enjoy the theatrics of loud, turbocharged engines and inhaling exhaust fumes. How will electric rallycross suit these motorsport enthusiasts?
The development and integration of an electric powertrain is expensive. Batteries, motors, inverters, additional wiring, safety features and more intelligent and powerful computer electronics will all be required. With World RX now manufacturer-free as Peugeot, VW and Audi withdrew from the 2019 championship, how will privateers afford to run these cars? And is Projekt E a ploy to entice manufacturers back into World RX?
So, although technically, electric rallycross makes sense, there are still plenty of challenges for integrating such an element into World RX. Projekt E however, aims to address all of these.
The Projekt E car was first revealed ahead of the World RX Latvia round on Friday the 13th of September 2019, with it’s first track run shortly after. It features STARD’s ‘REVelution’ powertrain which includes a 400V battery, two motors at the rear and one at the front. This produces 450kW (613bhp) of combined power, 1100Nm of instantaneous torque and a top speed of 240km/h. Each axle also features a mechanical differential, just like the conventional Supercars. So, the cars might not be noisy, but they’ll be quick.
‘The performance of the racecar will be impressive when you consider that in terms of torque, the power unit is capable of 0-90% in about 32 milliseconds,’ explains Paul Bellamy, Senior Vice President of IMG Motorsports. ‘The motors rotate at up to 14,000rpm. Projekt E will add a whole new, innovative dimension to rallycross in 2020.’
Then there is the cost or electric, and every effort seems to have been made to minimise this and make Projekt E a viable option for the privateers. Firstly, the regulations allow teams to utilise current chassis technology, so both current cars and new builds can be converted to carry the STARD REVelution drivetrain. This minimises the costs for the privateers, whilst allowing manufacturers to invest in other areas.
Furthermore, the motors and transmission are the same for both the front and rear axles, reducing costs as fewer spare parts are required.
Unlike Formula E or ETCR, standard spec road car motors can also be used. ‘One of the most important things, especially for the cost of the championship is the fact we can run any road car electric motor from a standard car and generate the same power as a current Supercar in total,’ explains Manfred Stohl from STARD. ‘There are so many manufacturers coming to the market right now with their electric cars and all of their motors can fit and run in this [Projekt E] car.’
To kick off this championship, STARD will be providing teams with everything they need to go electric. Once an order has been placed, the team will receive all the technical details and CAD data from STARD to start developing the chassis. Teams will also be taught about all the electrical aspects of running a Projekt E car. They will then receive a ‘kit’ which includes three motors, three inverters, the ECU and transmission. The team can use the same suspension as conventional Supercars and have freedom for set-up changes, STARD just need to have the necessary access to the rear of the car incase of any issues.
‘It’s an exciting time for the sport of rallycross, says Bellamy. ‘Our aim with the new-look race weekend format for 2020, with the inclusion of Projekt E, is to allow rallycross fans to enjoy the traditional internal combustion engines – and be given a flavour of the future at the same time.’
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‘If you want manufacturers in motorsport the only way is to talk about electric, but we don’t want to alienate the existing teams who have invested in IC engines,’ highlights Torben Olsen, Managing Director of World RX for IMG, the promoter of World RX. ‘So, we will make sure that there is a transition period for them and our fans. We are embracing electric racing but we are looking at a model that is cost efficient for the teams but still attractive for the manufacturers. But if any type of motorsport lends itself to electric, it is rallycross.’
Rallycross will be going electric in 2020, and technically it makes sense.
Did you Know?
Integrating an electric powertrain into a rallycross car has been done before. STARD developed its own electric rallycross car using a Peugeot 207 S2000 chassis back in 2017. This proves that it not only can be done, but also that an electric powertrain can withstand the brutal environment of rallycross as shown in the video below. To discover how this was achieved download our FREE rallycross supplement.
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