Subaru Impreza WRX STI Spec C: First Look

Jay Williams - 29/July/2009

Tokyo, Japan – Fuji Heavy Industries Ltd. (FHI), the maker of Subaru automobiles, has launched the "Subaru Impreza WRX STI spec C", a new addition to the current WRX STI line-up. The new model is now on sale through Subaru dealerships in Japan.

Subaru has made several improvements upon the already available STI, which include an unspecified weight reduction, speculated to be in the range of 70kg. Subaru has achieved these figures through the use of an aluminum engine hood, a smaller battery and laminar glass on front and side windows.

The new Subaru Impreza WRX STI spec C comes standard with 18-inch seven double spoke lightweight alloys, with the choice of 17-inch alloys available as an option. The wheels are wrapped in Bridgestone Potenza RE070 tires which improve cornering and increase grip.

Just hope that you don't ever get a flat tyre, as the new WRX STI spec C model doesn't come with a spare tyre in the boot, instead customers have a flat tyre repair kit.

Subaru has increased performance via a newly tuned (ECU) Engine Control Unit. The new spec C also features a re-designed turbo-charger that uses new ball and axle bearings. These changes improve torque to 422 Nm at 4,400 rpm while the car still has a power output of 227Kw (305hp).

Engine integrity is improved through the use of a "inter-cooler water spray system," that helps keep intake-air temperatures down.

Subaru has opted for a mechanical LSD (Limited Slip Differential) instead of a Torsen type unit to improve traction in the corners. They have also tweaked suspension, springs, and fuel pump. All Subaru Impreza WRX STI spec C models come with gold Brembo brake calipers as standard.

Alcantara and leather mixed Recaro seats are available as an option. The car will be available in either Sunrise Yellow or Pure White, but the photos shown include a version in blue.

This rally bred machine will be limited to just 900 units, price listings have not been released.

Outline of Subaru Impreza WRX STI spec C

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 stabiliser and rear sub-frame bushes optimise 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 bonnet 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 in weight reduction.

Others:
A structural change of fuel pump provides stable fuel delivery even on high-load driving.

Gold colored "brembo" brake calipers are standard.

The "RECARO" seats (Alcantara and leather combination with red stitch) are optional on models with 18-inches alloy wheels.

Two exclusive exterior colours 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.

Related Links:
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- Subaru Liberty GT Spec.B - Tuned by STI (Road Test)
- Subaru WRX STI 20th Anniversary (2009)
- Subaru Impreza WRX (2009)
- Subaru Impreza Sedan (2009)
- Subaru Forester Diesel (2009)
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- Subaru Exiga (2008)
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- Subaru Tribeca (2008)
- Subaru Impreza World Rally Car (2008)