Details with the new Subaru Impreza WRX STI spec C that goes on sale only in Japan starting from today, have been released today by the automaker. What sets the Subaru Impreza WRX STI spec C apart is the fact that its engine and chassis received a series of improvements while the vehicle’s body is now lighter, so future customers can experience a new level of performance and excitement.
Under the bonnet the Subaru Impreza WRX STI spec C has a turbocharged 2.0-litre 4-cylinder DOCH engine that can develop 308 PS (227 kW) at 6,400 rpm and 422 Nm of torque at 4,400 rpm and production will be limited to 900 units.
More specific details with the list of modifications and enhancements featured on the Subaru Impreza WRX STI spec C in the official press release below .
Subaru press release :
Fuji Heavy Industries Ltd. (FHI), the maker of Subaru automobiles, today launches the “Subaru Impreza WRX STI spec C”, a new addition to the current WRX STI line-up. The model goes on sale today through Subaru dealerships in Japan.
Based on the Impreza WRX STI, the iconic sport model of Subaru, the WRX STI spec C model features enhanced engine and chassis performance as well as a lighter body on the premise of driving in motor sports. The model further strengthens its presence in the high performance car arena by offering sheer excitement and unique driving sensations as a distinctive road sport model, in line with the performance level originally delivered by the Impreza WRX STI.
The turbocharger newly adopted ball bearings for the turbine axle bearing, and the ECU (Engine Control Unit) program was also exclusively tuned. Thus the engine of the spec C model provides quicker response and improved accelerating performance. Thanks to its specially designed front & rear suspensions and improved body rigidity, the chassis offers stable and linear driving control even in marginal driving conditions. The adoption of an aluminum engine hood, laminar window glasses and a downsized battery resulted in a lighter body, which further polishes the model’s driving performance.
Subaru enhanced the WRX STI line-up by introducing this STI spec C model, in addition to the STI A-Line model, the AT version introduced in February this year.
Enhancement of Engine performance:
– Ball bearings of the turbine axle were newly adopted to reduce friction in the turbocharger. With the optimized ECU programming, the engine offers smoother and quicker response to the accelerator pedal and excellent accelerating performance.
– An inter-cooler water spray prevents rise in intake-air temperature at continued high-load driving, providing stable engine performance and improved efficiency.
Enhancement of Chassis performance:
– Reinforcement of the cross member in front-suspensions offers a linear steering response.
– Specification changes in damping force of suspensions, coil spring rate, rear stabilizer and rear sub-frame bushes optimize rigidity for body roll and retain excellent road-holding capability.
– Rear LSD (Limited Slip Differential) system was changed to a mechanical type from a Torsen type to obtain the steady and powerful traction during cornering.
– Bridgestone “POTENZA RE070” (245/40R18) were adopted to enhance cornering ability and higher grip performance, especially in dry conditions.
– Nimble handling with a firm steering feel is assured by increasing oil flow volume in the power steering system.
Lightened body:
– An aluminum engine hood and a downsized battery, which make the front section of the vehicle lighter, produce better maneuverability.
– Laminar glasses were adopted in the front and side windows. They lightened the upper section of the body weight, resulting in improved stability during cornering.
– Newly-designed lightweight 18-inches alloy wheels are standard to offer excellent road-hugging property by reducing unsprung weight. (17-inches alloy wheels are optional)
– A flat tire repair kit is standard, which also helps weight reduction.
Others:
– A structural change of fuel pomp provides stable fuel delivery even on high-load driving.
– Gold colored “brembo” brake calipers are standard.
– The front bucket seats (fabric with red stitch) are standard on models with 18-inches alloy wheels.
– The “RECARO” seats (Alcantara and leather combination with red stitch) are optional on models with 18-inches alloy wheels.
– Two exclusive exterior colors are available; Sunrise Yellow and Pure White.
– The production is limited to 900 units.
Major specifications:
-Engine type: Horizontally-Opposed 4-cylinder DOHC 16-valve turbocharged engine
-Displacement: 1,994 cc
-Maximum output: 227kW (308 PS)/6,400 rpm
-Maximum torque: 422 Nm (43.0 kgf·m)/4,400 rpm
-Turbo type: Ball-bearing type twin scroll turbocharger

Source: Subaru