KEY POINTS:
More air, more power, more torque - that's part of the performance package British tuning house John Cooper Works used for engines in the Mini Challenge race cars.
The rest of the revisions included bigger brakes, optimised suspension settings and a stronger gearbox, all core go-faster components now available in JCW versions of the street-legal Mini Cooper S hatchback and Clubman.
The uprated models from the famous British tuning house have just arrived in New Zealand and will go on sale in October, priced from $59,990.
The engine in the JCW cars is the same as that developed for the Mini Challenge race cars.
The basic unit is the four-cylinder 1.6-litre powerplant that comes with the standard Mini Cooper S, but modifications have been made to the air filter, air mass meter, exhaust system and catalyst.
The changes boost power to 155kW (211bhp). Maximum torque of 260Nm comes between 1850 and 5700 rpm, but an overboost function hikes it briefly by 20Nm to 280Nm. The JCW hatch sprints from zero to 100km/h in 6.5 seconds, while the Clubman is just 0.3 seconds behind. Both cars have a maximum speed of 238km/h.
The six-speed manual gearbox has been strengthened to handle the extra power.
The standard Sports button, located in front of the gear lever, activates an engine control map which produces even more dynamic performance and sharper steering response, says Mini.
Air supply to the modified larger turbocharger is increased through a larger air intake pipe, which in turn creates a quicker induction phase.
The engines also come with reinforced, specially polished pistons, as well as a strengthened cylinder head for optimised stability and a modified cylinder gasket. The intake valves and valve seat rings have also been upgraded with stronger and more resistant materials to cut the engine's compression ratio.
The new sports exhaust system gets stainless-steel twin tailpipes. Modifications to the system also helped to reduce counter-pressure at the point of exhaust gas recirculation.
Ducts in the exhaust manifold and turbocharger are split between two cylinders each. Congestion is therefore minimised when air is inducted to the turbocharger and turbo lag is virtually eliminated.
The JCW Minis are the first models in the range to fulfil all the requirements of the European EU5 emission standards that come into force in 2009. Tailpipe emissions are 165g/km for the hatch and 167 for the Clubman.
The material used in machining the turbine has been upgraded for the engine, with maximum charge pressure increased from 0.9 to 1.3 bar. This lengthening of the combustion process helps to achieve the higher torque curve of the JCW car at 260Nm at just 1850rpm.
The JCW package adds dynamic traction control on top of other electronic safety aids including anti-lock brakes, electronic brake force distribution, cornering brake control, electronic differential lock, dynamic stability control and hill assist.
DTC allows controlled slip on the drive wheels. On a slippery surface, the driver can pick up speed in a controlled manner with the front wheels spinning slightly.
When reaching the upper limit, DSC will intervene as usual, but the driver can deactivate the DSC/DTC systems if desired with a button.
In the DSC-off mode, the standard electronic differential lock can be activated and controls cornering at higher speeds. If one wheel loses grip, drive is transferred to the wheel with better grip.
The JCW cars come with an uprated suspension system. As an alternative, a sports chassis with harder damper characteristics and stronger stabilisers is available for the front and rear axle.
Customers who might want to race their cars in club events can opt to lower the suspension by 10mm with even harder damper characteristics and stabilisers.
The uprated braking system includes bigger discs front and rear. The 17-inch alloy wheels are the lightest standard wheels available within the JCW environment. The high-speed tyres are runflat units and the cars are equipped with a tyre damage display function.
Ten exterior paint finishes are available with the JCW cars, along with special JCW badging and trim.
