JDM AWD /// platform file
Subaru WRX (2015–21) build guide
FA20DIT · 2.0 turbo flat-4. What the stock hardware reliably supports, where it breaks first, and the fastest safe path to more.
The Subaru WRX (2015–21) makes 268 hp stock at roughly 3,300 lb (12.3 lb/hp). Its stock internals are good for about 400 hp, the fuel system for around 350 hp, and the stock turbo(s) flow about 340 hp. Below is the limit sheet carbuildcheck analyzes against, plus the platform's documented weak points.
01 Factory card
Stock power268 hp
Curb weight3,300 lb · 12.3 lb/hp
LayoutAWD
InductionTurbocharged
02 What stock parts support
Engine internals~400 hp
Fuel system~350 hp
Induction ceiling~340 hp
Clutch (manual)~310 hp
Transmission (auto/DCT)~360 hp
Cooling (sustained)~370 hp
Community-documented crank-hp planning figures, conservative by design. How these are used in the score →
03 Where it breaks first
FA20DIT rods are the fuse. Conservative tunes live long lives; aggressive off-the-shelf maps end up on engine stands.
Same rule as the EJ: the tuner matters more than the parts list.
04 The typical path
Stage 1 tune → intake → downpipe → intercooler → Stage 2 tune. Fueling before E85, driveline before sticky tires.
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