Project ILL STI

The Brief

The “Ill STI” — Built for Power. Built to Drive.

After the original engine failed, Carlos brought his 2013 Subaru STI to HG Performance with a clear objective: build a stronger, more reliable, and seriously fast STI while retaining the ability to drive it every day.

Carlos already had a general vision for the car, and HG Performance’s job was to turn that vision into a complete, cohesive performance build. Rather than focusing on power alone, the project was approached as a complete vehicle transformation, with the engine, turbo system, suspension, chassis, and tuning all working together.

The result would need to deliver serious performance, improved handling, and everyday drivability—creating an STI capable of feeling at home on both the street and a more demanding driving environment.

What We Did

At the heart of the build is a fully built Crawford Performance block, providing the foundation required for the STI’s substantial increase in power and reliability.

The engine was paired with a Full-Race twin-scroll turbo kit, featuring a BorgWarner 7670 turbocharger. This combination significantly transformed the STI’s performance while maintaining the flexibility needed for different driving conditions.

To properly manage the increased power, HG Performance incorporated custom engine management from Delicious Tuning. Multiple tuning maps allow the driver to adapt the vehicle’s performance characteristics to different driving environments, making the car considerably more versatile than a single-purpose performance build.

The chassis was upgraded to ensure that the additional power could be effectively controlled. SuperPro bushings were installed throughout the suspension system, improving chassis response, feel, and overall control.

The suspension transformation was completed with KW Suspension Variant 3 coilovers, giving the STI greater control and a more responsive driving character. The combination of upgraded bushings and adjustable coilovers provides a more capable platform both on the street and when the car is pushed harder.

With an extensive list of modifications spanning four printed pages, front and back, virtually every aspect of the vehicle was considered during the build.

Parts Fitted

• Crawford Performance built engine block
• Delicious Tuning custom engine management
• Full-Race twin-scroll turbo kit
• BorgWarner 7670 turbocharger
• SuperPro suspension bushings
• KW Suspension Variant 3 coilovers
• Multiple tuning maps for different driving environments

The Result

The completed 2013 Subaru STI delivers the balance Carlos was looking for: serious power, sharper handling, improved response, and everyday usability.

The Crawford Performance engine provides the foundation for the substantial increase in output, while the Full-Race twin-scroll system and BorgWarner 7670 turbocharger transform the car’s performance potential. Delicious Tuning’s custom engine management allows that power to be tailored to different driving conditions.

On the chassis side, SuperPro bushings and KW Variant 3 coilovers provide a more controlled and responsive driving experience, allowing the STI to make better use of its increased performance.

The finished car produces more than double the original power, while multiple tuning maps provide the flexibility to adapt the car to different driving environments.

Despite its extensive, track-inspired specification, the “Ill STI” remains a daily-driven machine.

The result is a Subaru STI built around its driver—a comprehensive performance build that combines power, handling, response, reliability, and everyday drivability without turning the car into something that can only be enjoyed on the track.

Built for power. Built to drive. Built to be driven every day.