Project Thunderball: Wiesmann’s all-electric convertible roadster

Luxury sports car brand Wiesmann has revealed more details of its all-electric vehicle, which it claims to be the world’s first electric convertible roadster.

The two-seater, rear-wheel drive Project Thunderball sees twin electric rear-mid mounted motors delivering up to 500kW (680hp) to the rear wheels and 1100 Nm of torque, bringing phenomenal straight-line performance and a targeted 0-62mph (0-100km/h) sprint acceleration time of 2.9 seconds.

Project Thunderball has been built on a bespoke chassis architecture with its powertrain components cleverly packaged to provide the lowest possible centre of gravity. To keep the typical roadster proportions, the position of the driver and passenger are positioned as far backward as possible.

With lightweighting key to efficiency, the vehicle’s powertrain combined with its carbon fibre body astonishingly weighs in at little more than 1700kg (3747lb), providing 2.5kg per HP of performance.

At the heart of the vehicle lies one of the most energy and power-dense battery packs available, providing a target range of 500km (310 miles). The 92kWh (83kWh available), Li-ion NMC, “module-to-pack” technology is based on series modules with integrated pouch cells, which in total weigh a very lightweight 500kg,

In addition to this, its 800V high-voltage architecture enables ultra-rapid 300kW DC fast charging at a public charger or charging domestically via its 22kW onboard charger. Charging is provided via a standard Type-2 charging port with AC- and DC charge ports.

To keep the battery performing at such a high level, Wiesmann engineers have developed a sophisticated thermal management system for the battery module. Using a water-glycol mix, the modules are cooled via a bespoke designed, flow-simulated and optimized cooling plate, which transfers the heat to the base of the module as quickly as possible.

A bespoke Battery Management System [BMS] has also been developed, which has given Wiesmann engineers the freedom to adjust, calibrate and fine-tune the vehicle’s drivability that is optimised for all driving states and ambient conditions.

Roheen Berry, CEO of Wiesmann, said: “The continued development of Project Thunderball is bringing Wiesmann ever closer to the goal of producing what will be the world’s most exciting electric sports car. Thanks to endless research and testing, the roadster will blend our bespoke cutting-edge powertrain technology with Wiesmann’s trademark German engineering excellence. We are putting the emotion back into EVs. Which is why technology has been a key part of this project, creating a vehicle that not only has the stunning looks of a true Wiesmann, but also drives like a world-class sports car.

“I am equally pleased to say that we have had an enthusiastic response from customers. Since opening the reservations list at the end of September, we have ¾ of the first year of production slots allocated, proof that they are just as excited about the new technology in Project Thunderball as we are.”