STI - DESIGN & ENGINEERING

STI's goal is to create the only car in the world that seamlessly blends with a person's senses. A car that pulls in a person's senses and emotions. Complete harmony between driver and car. Achieving this goal will make driving even more enjoyable.

What is driving?
What is enjoyment?

We constantly ask ourselves these questions.
People's feelings cannot always be captured as facts. “Truth” conveyed by numbers and “truth” conveyed by feelings do not always match. This is why when we create cars, we focus on the human sense: the sensation of lightness more than the actual weight itself.
An emphasis on making cars that are for people comes before rationalization, efficiency and standardization.
In the extreme world of motorsports, we gauge our own level, inspect every avenue of engineering, and use this knowledge to develop and create commercially available car parts and complete cars. The same people are involved in producing racecars and consumer cars, and the same technology and care is put into their production. This attention to detail and non-compromising attitude is what STI is all about.
We are confident our products, lovingly thought out and obsessed over, will bring you joy. A car that is not just a means of transport but something that becomes a part of your body. We want to provide you with that one irreplaceable car.

Introducing the history of STI's complete cars

IMPREZA 22B STI version (released in 1998): The Impreza 22B STI version was a road model recreating the look and feel of the ‘Impreza World Rally Car 97', which won the World Rally Car category for three consecutive years in the World Rally Championship. Its features included extruding front and rear blister fenders, a bumper with an integrated front grill, an aluminum hood with brace grill, side skirts, and a large rear spoiler. The body color was STI's iconic Sonic Blue Mica. The displacement of the 4-cylinder/4-cam, 16-valve turbo and horizontally opposed engine, known as ‘EJ22 modification,' was increased to 2212 cc. Although maximum output stayed at 280PS, its engine could achieve a flat high torque at a rotation range from 2800 to 5200 rpm and a stress-free increase of revolutions up to 7900 rpm. In the close-ratio transmission with driver-controlled center differential, materials for the main shaft and 2nd driven gear were reinforced, and special hard shot peening was added to all gears. By combining a twin plate clutch, it was able to handle the high output and high torque that the engine produced. For the suspension, specially tuned Bilstein dampers and Eibach springs were used, just as in the WR car, while its 235/40/17 tires were fitted with gold-colored BBS forged aluminum wheels. The car's Super Quick Steering Gearbox had a steering gear ratio of 13:1, giving this vehicle the reputation as a road model version of the WR car.
S206 (released in 2011): The S206 is a complete car based on the WRX STI 4-door Sedan, with improvements in maneuverability, driving feel, and interior and exterior look. The S in S206 is only given to STI's top-grade models. It is positioned as the ultimate road car with the soul of the WRX STI, which won the SP3T class in the 24 Hours Nürburgring race in 2011. As a victory celebration special package, we created the limited-edition S206 NBR CHALLENGE PACKAGE with a carbon roof and dry carbon rear spoiler. With only 100 units produced, reservations for this car were full almost immediately after release. The power unit has achieved a maximum output of 235 kW (320 hp) and maximum torque of 431 N·m (44 kgf·m) due to the ball bearing turbocharger and ECU tuning etc. Also, by including original chassis parts such as Bilstein dampers, coil springs and Flexible Tower Bars, and combining BBS 19-inch forged aluminum wheels with Michelin tires we have advanced the notion of “strong and flexible driving.”

Introducing STI's performance parts

Giving New Meaning to “Sporty Cars”: Even today, there may be some drivers who view sports cars as uncomfortable to drive. Here at STI, we do not believe in sacrificing ride comfort for performance. Instead, our ideal platform is one that allows drivers to enjoy their car to the utmost, while at the same time ensuring that other passengers are able to relax in absolute comfort. Our engineers have strived to achieve a point of optimum balance where both performance and comfort can be improved simultaneously. The Flexible Tower Bar was developed in our search for this optimum balance. Out on the road, cars are subjected to forces from every conceivable direction, all of which have a profound impact on the car's performance and interior comfort. The Flexible Tower Bar was designed with the aim of controlling these forces to maximize performance. The Tower Bar itself features a unique layout, divided into separate left and right sections and connected by ring balls, which serves to suppress any lateral movement, while offering flexibility in the longitudinal direction. Settings have been tightened where needed, and loosened in other areas to achieve superb handling and straight-line performance, and at the same time outstanding ride comfort. The full potential of the original model has been extracted without affecting its balance. This is the ideal platform that STI believes is required for a sports car.
Proposing the Best Overall Balance: The sheer number of sports and performance accessories, including those other than from STI, is simply unfathomable. While a certain part may appear just as promising as any other part, the performance that the driver is looking for may not be achieved simply by installing parts at random. Performance parts designed for racing circuits may, more often than not, be unsuitable for normal road-going cars. Yet we have worked hard to ensure that driving enjoyment is accessible to anyone, without the concern or disappointment that is often associated with special performance parts. The result is our “STI Performance Package.” The capabilities of the car as a whole has been taken into account, tweaked for greater performance in some areas, and relaxed in others. The package increases traction between the tires and the road, and improves steering response, all without sacrificing ride comfort. Designed to bring out the perfect balance for each and every SUBARU, the STI package is a culmination of our approach to “Total Chassis Coordination.”
Maintaining Your Trust: There is an immense range of aluminum wheels that are available today, with each type focusing on a different aspect, including design, weight and durability. This often makes selecting the perfect wheel for your car a daunting task. STI aluminum wheels make selecting the right design so much easier for you, by ensuring a perfect fit every time. STI wheels are lightweight so as to reduce unsprung weight, while at the same time exhibiting extreme durability required for on-the-edge, spirited driving. While the wheels look good by themselves, they are designed from the ground up to complement your Subaru in every conceivable way. Drive easy, knowing that your perfectly matched wheels symbolize the extensive knowledge that we have of Subaru.
Not Just Parts, Total Concepts: When suspension is mentioned, the mind automatically thinks of shock absorber damping forces and varying spring rates, stiff or weak. Naturally, stiff springs deliver a rougher ride. Yet we do not look at suspension in the same way. Instead, suspension is considered a vital part of the car, acting as a bond between the road surface and the chassis. The ideal suspension setup can only be designed by taking into account body rigidity, weight of tires and wheels, and characteristics of that particular car. STI suspension kits are designed with this in mind. Rather than focusing merely on numbers for damper and spring rates, extensive test runs are conducted to determine suspension settings are optimum for that car. The driving characteristics of the base model are retained and performance increased throughout every aspect, all with the luxury that is a super smooth ride.
Performance You Can Trust: STI spoilers and body parts are designed to give the car maximum handling and stability at high speeds. Repeated testing in wind tunnels and around the Nürburgring test circuit have been conducted in order to find the optimum balance between Cd values (aerodynamic drag) and Cl values (aerodynamic lift). The performance of spoilers and body parts are usually only evident at high speeds, and these parts may not make any noticeable difference when driving on ordinary roads. Yet even with this in mind, it is our goal to ensure that customer cars are fitted with parts that offer high performance and high reliability. Complementing the design of parts is a sophisticated, streamlined sense of Beautility - beauty combined with useful practicality. If drivers and passengers gain a feel of sophistication and satisfaction when driving a car fitted with STI spoilers and parts, our goal has been fulfilled.