Concept Cars

At-A-Glance / Overview

Hi-resolution Images / Desktop Wallpapers

Green Cars

Tuned, Modified, Custom Cars

Car Videos

Japanese Cars Specifications

RSS Feed is on YouTube is on Twitter.  Follow Us is on Facebook.  Become a Fan

Cosworth Subaru Impreza STi CS400 ‘The Ultimate Impreza’

The Cosworth Impreza STi CS400 is the product of a comprehensive Cosworth engineering program, boasting supreme levels of pace that put it on a par with some the world’s greatest performance cars.

The launch of the CS400 provides a powerful demonstration of Cosworth’s engineering expertise in the automotive sector – one of four major areas of activity for the business in 2010 alongside the defense, clean energy generation and sports industries.

The CS400 sports an engine upgrade which produces 33% more power than the standard STi model, enabling this 4 seat family car to go from 0-62mph in just 3.7s. This searing pace is more than a match for some of the world’s most revered sports cars, including the Lamborghini Gallardo LP560 and Porsche 911 GT3.

Rather than concentrating solely on delivering more power, the CS400 has been engineered to deliver the full performance experience, featuring custom brake components developed in partnership with AP Racing and a modified suspension and handling package. In creating “The Ultimate Impreza” Cosworth has ensured that the CS400 employs simple, efficient enhancements in order to remain and as close as possible to the original design to guarantee reliability and easy maintenance at regular Subaru dealerships.

2010 Cosworth Subaru Impreza STi CS400 – Hi-res. Images

2010 Subaru Cosworth Impreza STi CS400
2010 Subaru Cosworth Impreza STi CS400
2010 Subaru Cosworth Impreza STi CS400
2010 Subaru Cosworth Impreza STi CS400
2010 Subaru Cosworth Impreza STi CS400
2010 Subaru Cosworth Impreza STi CS400
2010 Subaru Cosworth Impreza STi CS400
2010 Subaru Cosworth Impreza STi CS400

Scheduled for an exclusive launch in the UK this summer with a limited number of 75 vehicles planned, the Cosworth Impreza STi CS400 marks an exciting return to the roads for Cosworth as it carries the reputation for value-for-money performance to a new generation of car enthusiasts.


New turbocharger and ‘breathe easy’ exhaust systems
An all-new Cosworth turbocharging system features a new compressor design and wastegate actuator to supply up-rated boost pressure and deliver increased power.

A unique exhaust system was developed to allow the engine to ‘breathe’ more easily and unleash its full potential. Larger capacity tubular manifolds and increased diameter downpipes speed up the evacuation of hot gases. The first catalyst is a non-restrictive design and larger tail pipes give the exhaust note a unique tone.

After the in-depth Cosworth performance upgrade which includes an ECU re-map, the boxer engine in the CS400 generates 33 per cent more power (400 ps at 5,750 rpm, compared with 300 ps at 6,000 rpm for the standard Impreza WRX STI), and 542 Nm of torque, while remaining within the torque capacity design limits of the original Impreza drivetrain.

Manual transmission and All-Wheel Drive system
To handle the increased power of the Cosworth-tuned engine, the Impreza STI’s six-speed manual transmission has carbon synchromesh applied to the top three ratios and a short throw linkage for quicker shifting.

There is also an upgraded single-plate clutch with a revised pressure plate, bearing and disc. The gearbox and final drive ratios are unchanged.

The Cosworth Impreza’s full-time All-Wheel-Drive transmission with front and rear limited-slip differentials, features a 50/50 front to rear torque split as the default, however, the torque split is varied electronically according to changing conditions. The multi-mode Driver Control centre differential with viscous coupling senses which axle has the better grip and varies the split ratio in milliseconds to distribute torque accordingly, thus maximising traction and minimising the possibility of wheelspin.

Fine-tuned suspension
Improving the Cosworth Impreza’s handling, steering feel and driver feedback – without compromising ride comfort – was a primary target for the development team.

Retaining Subaru’s original suspension layout and major components, Cosworth and a team of chassis engineers collaborated with Bilstein and Eibach technicians to tailor a ride/handling/steering package that was ideally matched to the new model’s increased performance.

Special Eibach coil springs and new Bilstein inserts, featuring unique damping characteristics, were manufactured to Cosworth’s specifications. The ride height was lowered by 10 mm at the front.

The benefits of this fettling are twofold. Firstly, there is a big improvement in ride quality generally, making the Impreza easier to live with on a day-to-day basis. Secondly, its on-the-limit behaviour is more focused and composed. The damping upgrades mean that there is less pitch and roll when turning into corners, meaning that keen drivers can get back on the power earlier and make the most of the car’s Symmetrical All-Wheel-Drive system.

Upgraded ‘racing’ brakes enhance stopping power
To match the new Impreza Cosworth’s supercar pace, Cosworth commissioned AP Racing to develop more powerful front brakes. Larger diameter (355 mm) ventilated front discs were adopted, with motorsport-style six-pot callipers featuring bespoke pistons operating on larger brake pads.

The difference in performance is immediately noticeable. The harder pads help to minimise fade, meaning that drivers can count on the AP stoppers for effective retardation time and time again.

The standard Impreza WRX STI’s rear brake discs, overall brake balance and original ABS system have been retained.

‘Stand-out’ looks, plus new style wheels
The outstanding performance of the Cosworth Impreza is reflected in its ‘stand-out’ appearance and standard Xenon headlamps. The lowered ride height and wider track give the car a whole new stance which is reinforced by a new shape front bumper, new fog lights, upper and lower mesh grilles and a new rear spoiler.

Discreet Cosworth badging is carried on the lower grille, front seats, brake callipers and floor mats. Individually numbered plaques are fitted on the engine and door sills. Each Cosworth Impreza STI CS400 is supplied with a numbered certificate of authenticity.

Although the new model’s alloy wheels are a similar overall size to those of the regular Impreza WRX STI model – 18 x 8.5 inch – they are lighter and stronger. Called ‘Pro Race’ and finished in anthracite the latest wheels from the Team Dynamics range were selected as compatible with the Subaru’s five-stud design. These wheels have a 43 mm offset (the standard STI wheel’s offset is 55 mm) and extend the track by 12 mm – improving handling and filling the car’s wheel arches more effectively for a more aggressive stance.

The new wheels are fitted with high performance, low profile Michelin SP3 tyres chosen for their dry- and wet-road grip, durability, and low noise levels. Tyre size is 245/40 R18 and the tread pattern is directional.

Interior modifications and generous premium equipment
Inside, the sporty new Recaro front seats, the rear seats and steering wheel are all re-trimmed in Cosworth-branded black leather. Also distinguishing the CS400 are Piano Black centre stack and trim accents, and the fitment of privacy glass.

Standard features carried-over from the WRX STI model include: LED (light-emitting diode) tail lamps, front and rear electric windows, 10-speaker, six-disc radio/CD player, satellite navigation, Smart-entry and push-button start, plus front, side and curtain airbags.

Share Your Thoughts