[TMS] Fuji Heavy Industries Unveils 308PS Impressa WRX STI

Oct 25, 2007
Tatsuhiko Hayashi, Nikkei Automotive Technology
Impressa WRX STI
Impressa WRX STI
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Front view
Front view
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Side view
Side view
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Rear View
Rear View
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Fuji Heavy Industries Ltd unveiled a high-performance version of Impressa "WRX STI" at the 40th Tokyo Motor Show. The price is ¥3.65 million (US$31,966). The model was released on the same day, targeting the sales of 450 vehicles per month.

The 2.0-L horizontally-opposed 4-cylindar turbo engine "EJ20," which reduces resistance in the intake/exhaust system and adopts variable valve timing structure on both intake and exhaust sides, enhances low-end to mid torque and generates the torque equivalent to 90% of the maximum torque (422N·m) at 2,400rpm.

The maximum output reaches 227kW (308PS) at 6,400rpm. The transmission is a 6-speed manual type.

The body is dimensioned 4,415 (L) x 1,795 (W) x 1,475mm (H), while the wheel base is 2,625mm. Compared with existing models, the total length has decreased by 50mm and the total width has increased by 55mm, while the wheel base has increased by 85mm.

The length of wheel base, which was increased by moving forward the front wheels by 5mm, is longer than standard models, excluding the STI released in June 2007.

Both 4-door models and 5-door models are released in North America. For WRZ STI 5-door packages, front and rear overhangs have been shortened for better handling in motor sports such as a rally, while the wheel base and the tread was extended to enhance driveability and stability in straight driving.

The 4-wheel-drive system is equipped with torque-responsive LDS (limited slip differential) on front and rear differentials, while "DCCD," a combination of mechanical and electronic LSDs, is installed on the center differential.

In addition to conventional modes of AUTO and MANUAL, it offers "AUTO +" mode, an automatic mode with priority on traction, and "AUTO -" mode, an automatic mode with priority on turning performance, so that the driver can select an appropriate mode that matches better to the driving condition. The basic torque distribution for front wheels and rear wheels is 41:59.

The antiskid system offers three modes: NORMAL, TRACTION, which delays the operation timing and is appropriate for sports driving, and OFF, in which ABS only operates.

The chassis has been strengthened to match the high-output power train. Inverted struts are installed on the front side. The weight was reduced while the side rigidity was improved by adopting lower arms made of wrought out aluminum alloy exclusive for WRX STI.

The double wishbone installed on the rear side is more effective for reducing the variation of camber compared with struts used on conventional models. For standard models, durability and rigidity have been improved by reinforcing the pillars around the rear gate.

In addition, an improved version of "SI-DRIVE," which is used in "Legacy," is loaded on this model to achieve the maximum torque in the energy-saving "intelligent" mode. In Legacy, the intelligent mode is designed to keep the maximum torque low. The vehicle weight is 1,470kg (when 17 inch tires are used) and the fuel consumption at 10·15 mode is 10.4km/L.