The Subaru Forester STI is equiped with a 2.5 litre turbocharged engine.
The previous owners exchanged the stock turbo for a larger TD06-20G.
Due to the larger turbo, the Subaru’s horsepower increased, though the turbo lag increased as well.
As can be seen in the graph below, the turbo threshold is fully eliminated thanks to the TORQAMP.
To feed enough air at high rpm the bypass valve is used.
SUBARU FORESTER STI
2.5lit.
engine size
turbocharged
aspiration
torque
new torque
horse power
new horse power
