The inaugural season for the new hybrid era of the British Touring Car Championship (BTCC) came to an end on October 9th, 2022, marking the first-ever hybrid touring car championship worldwide to complete a season. BTCC’s hybrid system is spec one developed by Cambridge, UK, based Cosworth.

The primary target for the hybrid drive was 15 seconds of deployment per lap when the system was available to a given driver. This translated to that car gaining 15m within those 15 seconds, assuming a corner exit speed of 100km/h. The organising body, TOCA, didn’t want it to act like a DRS, only being deployed in some regions of the circuit and only rewarding chasing drivers, as it believes this overtaking is too fabricated. Instead, it wanted a push-to-pass system that drivers could use at the exit of a corner to try and bring them alongside opponents in the next corner. However, the driver in front would also be able to push to defend that position, keeping racing close.
The motor, the inverter and the ancillaries needed to be primarily off-the-shelf components for cost reasons. The only part that sits outside of that is the battery, which has been designed uniquely for BTCC by Delta-Cosworth. Because this is a hybrid system, and it isn’t the primary driver for the vehicle, peak efficiency isn’t the main driver. For the specification, BTCC needed a system that could deliver the duty on the lap the driver demands and push energy back to the battery to...