Hardcore Impreza STi just for Japan

A harder version of the WRX STi - Spec C - will only be available new in Japan.

All-wheel drive specialist Subaru has introduced a harder-edged version of the Impreza WRX STI - but just 900 examples will be available in Japan.

Based on the Impreza WRX STI, the WRX STI Spec C model features enhanced engine and chassis parts and a lighter body. Among the improvements is a water spray for the inter-cooler to prevent increases in intake-air temperature, providing improved engine efficiency.

The current STI doesn't have a water spray for the inter-cooler, although previous STI models did. It is understood the rally industry pushed for the change and Subaru built the 900 special-edition examples for homologation purposes. The turbocharger turbine shaft has new ball bearings and the engine control unit programme has been retuned.

This provides quicker throttle response and improved acceleration, says the carmaker. The Spec C is rated at 227kW at 6400rpm and 422Nm of torque at 4400rpm.

Subaru says the specially designed front and rear suspension and improved body rigidity offers stable and linear driving control even in marginal driving conditions, and greater oil flow in the power steering provides a firmer steering feel.

The adoption of an aluminum bonnet and a smaller, lighter battery aids manoeuvrability with less weight over the front wheels, while laminated side and rear window glass result in a lighter body with a lower centre of gravity, which further polishes the WRX STI Spec C's performance.

Reinforcement of the front cross member offers a greater linear steering response, says the carmaker. Changes in damper ratings, coil spring rates, rear stabiliser and rear sub-frame bushes improve rigidity to counter body roll and retain the car's excellent road-holding.

The rear limited-slip differential has been changed to a mechanical type from a Torsen diff to improve traction during cornering.

Bridgestone Potenza RE070 (245/40R18) tyres are used on the lightweight 18-inch alloy wheels which reduce unsprung weight to improve cornering ability and road holding.

A tyre repair kit is standard, instead of a full spare wheel to reduce weight. Gold-coloured Brembo brake calipers are also standard.

Buyers have the choice of standard bucket seats, or Recaro seats sporting alcantara and leather combination with red stitch. Two exterior colours are available: yellow and white.