An updated John Cooper Works tuning kit has been developed for BMW ’s British-built Mini Cooper S.

The new kit boosts power to 210bhp, giving the sporty subcompact a 0-62mph (100km/h) time of 6.6 seconds and a top speed of 143mph.

The kit will be available worldwide, for both the Cooper S hatchback and Convertible, and will be launched at the Paris Motor Show on 23 September.

Despite the increase in power, the price for the updated kit is unchanged in the UK, at £2,999 plus 10 hours’ labour for fitting.

The performance upgrade has principally been achieved through changes to the air filter system, allowing greater airflow at high revs (above 4500rpm) by triggering an extra air intake flap to reduce pressure losses within the intake system. New fuel injectors and engine management calibration are also required to ensure optimum performance and durability under all operating conditions.

The arrival of the new Works kit was spurred by updates to the the Cooper S earlier this year, including changes to the gear ratios in the six-speed GETRAG gearbox.

Owners of cars with the older kit can have an upgrade (new air filter intake system, injectors and calibration) fitted by a Mini dealer for £335 plus an hour’s labour. Both the new kit and upgrade are fully approved by the car maker and do not affect the factory warranty or optional ‘tlc’ service plan.

The upgraded Works kit was put through 150,000 road miles of durability testing and 20,000 miles of high-speed testing in temperatures from +35C to –20C.