Uploaded July 2026 | Updated September 2026, 2 weeks ago
Sometimes the best turbo upgrade... is no turbo upgrade at all.
This 2019 STI proves just how rewarding a well-sorted stock turbo setup can be.
Rather than chasing a larger turbo right off the bat, the goal was to maximize the potential of the factory unit while preserving the quick spool and immediate response that make the EJ feel alive and eager.
The build includes:
• COBB Flex Fuel
• AEM low-pressure fuel pump
• Injector Dynamics 1050 injectors
• Intake
• Intercooler
• Exhaust
After installing the parts, using the COBB Accessport, we developed custom calibrations for both pump gas and E50, giving the owner the flexibility to run either fuel. During the summer, it's as simple as filling up with ethanol and enjoying the additional performance.
The result?
Nearly 370 WHP on our dyno with a responsive, broad powerband that makes the car feel alive everywhere—not just at peak RPM.
A stock turbo, when supported by the right hardware and a well-developed tune, is an a super fun combination. Quick to spool, eager to respond, and more than capable of putting a smile on your face every time you drive it.
That's the beauty of a properly engineered Flex Fuel setup: everyday convenience when you need it, and substantially more performance when you want it.
#subarusti #wrxsti #cobbtuning #flexfuel #stratifiedtuned
Sometimes the best turbo upgrade... is no turbo upgrade at all.
This 2019 STI proves just how rewarding a well-sorted stock turbo setup can be.
Rather than chasing a larger turbo right off the bat, the goal was to maximize the potential of the factory unit while preserving the quick spool and immediate response that make the EJ feel alive and eager.
The build includes:
• COBB Flex Fuel
• AEM low-pressure fuel pump
• Injector Dynamics 1050 injectors
• Intake
• Intercooler
• Exhaust
After installing the parts, using the COBB Accessport, we developed custom calibrations for both pump gas and E50, giving the owner the flexibility to run either fuel. During the summer, it's as simple as filling up with ethanol and enjoying the additional performance.
The result?
Nearly 370 WHP on our dyno with a responsive, broad powerband that makes the car feel alive everywhere—not just at peak RPM.
A stock turbo, when supported by the right hardware and a well-developed tune, is an a super fun combination. Quick to spool, eager to respond, and more than capable of putting a smile on your face every time you drive it.
That's the beauty of a properly engineered Flex Fuel setup: everyday convenience when you need it, and substantially more performance when you want it.
#subarusti #wrxsti #cobbtuning #flexfuel #stratifiedtuned
