An electric drivetrain and traditional hand built sports car have been brought together in a concept car at the 2012 Geneva Motor Show. The Plus E is the work of traditional British sports car maker Morgan, which has used the new Plus 8 as the basis for the concept. The Plus 8 is built using Morgan’s lightweight aluminum platform chassis, developed and manufactured with specialist Radshape, first used in the Aero models, and fitted with a revised version of the company’s traditional open body.
For the Plus E concept, the 4.8-L BMW V8 is replaced with a Zytek electric motor as Rob Gibson, Business Process Development Engineer at Morgan, explained to AEI: “The objective of the project was to make an electric car that’s fun, but adheres to the Morgan principles of keeping it lightweight and interesting. The chassis is very similar to the Plus 8/Aero chassis. We’ve put some extra crossmembers where the engine mounts would normally be, there are cross members to support the battery packs, and there’s a subframe to support the motor and gearbox, but on the whole the architecture is very similar.”
To ensure even weight distribution, the battery pack has been split. There is a small battery pack at the back of the chassis where the fuel tank would normally be fitted, and the main battery pack is fitted in place of the engine. “That’s quite far back in the chassis to keep weight distribution even,” said Gibson.
The battery pack is rated at some 34 kW·h, and a working prototype at the Morgan factory is fitted with a Valence 32.5 kW·h lithium-ion battery pack. “Once the car is back at the factory, we shall be looking at a second-round engineering program, using a more powerful Zytek motor, a better inverter, and possibly replacing the five-speed manual gearbox with a five-speed sequential gearbox,” continued Gibson.
The show car was fitted with a 70-kW Zytek motor producing 300 N·m (221 lb·ft). Morgan says that the gearbox has been retained to maintain driver involvement, even though it is not strictly necessary. The gearbox is similar to those used in Morgan’s traditional 4/4, and the sequential gearbox that will probably replace it is likely to be sourced from transmission manufacturer Quaife. According to Gibson, the car is capable of reaching 60 mph (97 km/h) from rest in around 6.5 s and going on to a top speed of around 110 mph (117 km/h). Measured on the NEDC cycle, range is around 130 mi (209 km).
The current prototypes weigh in at around 200 kg (440 lb) more than the gasoline Plus 8, which weighs some 1100 kg (2425 lb), but Morgan is hoping to reduce the weight gain to around 50 kg (110 lb) in the second-round engineering program.
Gibson told AEI that the installation of the electrical drivetrain has been relatively straightforward: “Zytek have modified the motor a little to ensure that it could handle the forces introduced by the clutch plate. The casing has been modified to allow a bell housing to be fitted, and Zytek has modified the cooling paths. In terms of fitting it to the chassis, it has been really simple. The motor fits in the transmission tunnel where an automatic gearbox would normally fit, so the packaging works really well.”
The small battery pack is air-cooled, and liquid cooling will be used for the main battery pack. “The motor is currently being cooled through the standard aluminum radiator that we use for the gasoline engine,” said Gibson.