Formula E, season 1, was effectively a single make formula. All parts, including drivetrains, were fixed. This season, inverter, electric motor & gearbox can be the individual team's design, but the battery is still controlled.
Most interesting is gearboxes, or the lack thereof. Multiple ratio gearboxes are employed in internal combustion engine vehicles, because of the narrow range of engine speeds over which they can produce useful amounts of power. Electric motors are much less limited. For this reason, almost all commercial electric vehicles have only one forward gear. Two exceptions are Brammo motorcycles1 & General Motors’ Volt2.
However, all is not rosy with electric drive.
“... a problem with any electric motor is that as rpm rises, it begins to act as a generator & produce a turning effect (torque) in the opposite direction to the direction of rotation. Naturally, this reduces power & torque at the output shaft. This is the reason why some Tesla Roadster prototypes had a two speed gearbox. When rising motor rpm began to reduce torque, a change to the higher gear reduced both rpm & the reverse torque effect. Problem was, Tesla couldn't source a 2 speed gearbox which was light enough, small enough & also strong enough to withstand the Roadster's huge torque output, so production vehicles had only one forward ratio. Practical outcome: despite its huge acceleration (0 to 97 km/h (0 to 60 mph) in 3.7 or 3.9 seconds depending on the model), top speed is limited to 200 kph (125 mph).” — My Holden Volt2
For season 2, teams have taken advantage of the new gearbox rules. Every number of ratios from one (i.e. no variable ratio), to five, is being utilized.
1 gear: DS Virgin & NEXTEV TCR (formerly known as China Racing)
2 gears: Renault
3 gears: Abt
4 gears: Mahindra & Venturi
5 gears: Team Aguri
http://electriccarsreport.com/2015/08/formula-e-test-one-what-we-learn/?utm_source=dlvr.it&utm_medium=twitter
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1 AOL Autos/Translogic: “Brammo Empulse R Electric Motorcycle”, https://www.youtube.com/watch?v=pZjQjQUjgPs
2 My Holden Volt: “Does the ICE ever directly drive the wheels of the Volt?”, http://myholdenvolt.blogspot.com/2012/09/does-ice-ever-directly-drive-wheels-of_28.html / Sebastien Buemi Renault team first pre-season Formula E test Donington Park fastest Daniel Abt fastest first second sectors traffic final corners slowed down limited number of qualifying laps topping the timesheets lap time pre-season tests new technical changes season two teams design manufacture powertrain components energy battery turn the wheels inverter electric motor gearbox using the same battery speed pace efficiency manufacturers number of gears ratios electric motor instant torque power last year’s car five forward gears last year’s powertrain upgraded McLaren motor Mahindra four gears Venturi NEXTEV TCR DS Virgin direct drive system one gear gear changes per lap no power being delivered to the wheels regen braking slowing gear changes time different solutions Renault Abt last season electric motor sound one make series development is key defending champion Nelson Piquet Jr Andretti Trulli track Simona de Silvestro Old Hairpin grinding to a halt team corners Trulli team Jarno pre-season testing battery energy percentages manufacturer most efficient solution Renault e.dams Abt DS Virgin season starts in Beijing /
