The Formula E car broken down

Motor

Last sea­son there was a stan­dard motor for all teams, based on the McLaren P1 sports car. This year motor design has been opened up for devel­op­ment. Most teams have opt­ed to main­tain a sin­gle motor, but DS Vir­gin and Nex­tEV are the excep­tions. Both are run­ning twin motors in which two motors run on a sin­gle gear. It’s exper­i­men­tal, but Nex­tEV has con­firmed they will stick with a home-brew two-motor recipe next sea­son.

Tyres

All teams use the stan­dard Miche­lin For­mu­la E tyres. These are tread­ed rather than the slicks usu­al­ly seen on the rac­ing cir­cuit. Estelle Per­ri­er, the devel­op­ment engi­neer, explains: “To be able to decrease the num­ber of tyres you have to have a poly­va­lent approach – a tyre able to oper­ate in slick and wet con­di­tions. To be able to oper­ate in wet con­di­tions, even with a small quan­ti­ty of water, you need to have a groove.” They work well from 5C to 53C. At 18 inch­es wide, tyres offer low rolling resis­tance and less defor­ma­tion, which absorb ener­gy. And they look like ordi­nary road tyres – good from a mar­ket­ing point of view.

Steering wheel

Rac­ing afi­ciona­dos love unpick­ing the secrets of the steer­ing wheel. A For­mu­la E dri­ver has over­sized but­tons to alter brake regen­er­a­tion and torque, and a map switch to alter per­for­mance dur­ing the race, accord­ing to strat­e­gy. There is a radio but­ton to talk to engi­neers, a speed lane lim­iter for pit stops, a dash scroller, a but­ton to select neu­tral and a con­trol mark­er to help engi­neers mea­sure per­for­mance between points. On the back of steer­ing wheel is a “re-gen” pad­dle to recov­er ener­gy with­out using the brakes. Gear pad­dle-shifters are left and right. And top right at the back is the Fan­Boost pad­dle. Just hope you are pop­u­lar enough to need it.

Aerodynamics

Teams get the same stan­dard Spark-Renault car­bon fibre body­work, with two areas to play with. The front wing can be angled from 15 to 35 degrees and the rear wing can be shift­ed from 10 to 20 degrees. The greater the wing angle, the more grip; the low­er the wing angle, the high­er the top speed. The vari­a­tions
mat­ter. Teams will think through down­force strate­gies depend­ing on weath­er con­di­tions, dri­ver style and the track, often exper­i­ment­ing to try and gain the edge. It’s prob­a­bly the vari­able least appre­ci­at­ed by new fans.

Chassis

The stan­dard Dal­lara-designed chas­sis is mono­coque car­bon fibre. The crash test­ing for safe­ty rivals that of For­mu­la 1 for rigour. The front sus­pen­sion is the same on all the cars, but the teams are free to devel­op their own rear sus­pen­sion parts, so long as they are the same on each side. Will the chas­sis be opened up for devel­op­ment? In March, the FIA said it was look­ing to put the design out to ten­der, but may stick with a sin­gle design for all teams to keep costs down.

Battery cell

Every­one gets the same bat­tery cell. And that’s the way it’s going to be until at least sea­son five. Williams Advanced Engi­neer­ing pro­duces the 200kg lithi­um ion unit, which out­puts a max­i­mum of 28kWh of charge. Dur­ing the race, 170kW pow­ers the car, with an extra 10kW to 30kW unleashed by acti­vat­ing Fan­Boost to a total of 100kj or 50 horse­pow­er in old mon­ey. The future? Mahin­dra, DS Vir­gin and Renault con­firm they are look­ing at alter­na­tive bat­tery sup­pli­ers.

Gearbox

Com­pli­cat­ed? You bet. In the first sea­son, all cars ran with the same five-gear Hew­land box. This year it’s a jam­boree, with teams run­ning one, two, three, four and five gears. Motor rene­gades DS Vir­gin and Nex­tEV are on the sin­gle fixed gear, Andret­ti are using all five and the oth­ers are on oth­er com­bi­na­tions. Why? Weight plays a part. Strip­ping out gears low­ers weight. Each gearshift costs mil­lisec­onds of down­time. Renault e.dams have a starter gear and rac­ing gear. Which is best? Too ear­ly to decide. Gear phi­los­o­phy is quite sim­ply the hottest area of inno­va­tion right now.

3D illus­tra­tion by Gra­ham Mur­doch. All pho­tographs by FIA