Subaru Engine FA20 NA VS Turbo

 

The FA20 is Subaru’s modern 2.0-liter flat-four that powered the 86/BRZ and some Subaru models.

Below is the complete breakdown.

✅ Which cars use the Subaru FA20 engine?

1. FA20D (NA version – 200 hp class)

Used in:

• Toyota 86 / GT86 (ZN6)
• Subaru BRZ (ZC6)
• Scion FR-S (North America)

2. FA20F (Turbo version – 250–300 hp class)

Used in:

• Subaru WRX (2015–2021)
• Subaru Forester XT (2014–2018)
• Some JDM Subaru models with minor variations

✅ Is there a new version of the FA20?

Yes. The FA20D in the BRZ/86 was replaced by the FA24D in 2022+ models.

Modern replacement

• FA24D (2.4 L NA boxer)
  
• Used in: 2022+ Toyota GR86, 2022+ Subaru BRZ
• More torque, smoother midrange, and fixes many FA20D weaknesses.

FA20 Earlier Versions

• FA20D (2012 launch) → first version in 86/BRZ
• Updated FA20D (2017+) → slight compression ratio changes, valve spring updates, ECU revision
• FA20F → turbo variant for WRX/FXT
  So yes, there is an early version, mid-cycle improvement, and a turbo sibling.

✅ How much horsepower does the FA20 make?

FA20D (NA)

• 197–205 hp @ ~7000 rpm
• 151–156 lb-ft torque
  Varies slightly by market and year.

FA20F (Turbo)

• 250–268 hp (WRX global rating)
• 258–270 lb-ft torque
• Tuned versions (Japan) can reach 300 hp factory in some trims.

✅ Common modifications for the FA20 engine

1. NA FA20D (BRZ/86/FR-S)

Most popular mods:

• Header upgrade (EL/UEL) → +10–25 hp, fixes torque dip
• ECU tuning (OpenFlash, EcuTek) → best gains when combined with headers
• Cold air intake → small gains, improves sound
• Catback exhaust → small hp gain, improves flow
• Lightweight pulleys / flywheel → better engine response
• Oil cooler (important for track use)
• Flex-fuel / E85 tuning → +20–30 hp, huge torque improvement

Serious NA builds:

• High-compression pistons
• Cams + ported heads
• Full E85 tune
• Individual throttle bodies (rare, expensive)

Forced induction (supercharger/turbo kits):

A properly built FA20D can reach:

• 250–300 hp (safe range on stock internals)
• 350–400+ hp (needs forged rods/pistons)

⚠️ Common FA20 issues to expect

• Torque dip (solved with headers + tune)
• Valve spring recall (2013–2017 models)
• Oil consumption on early engines
• High oil temps during track driving (oil cooler recommended)
• Injector seals can fail on boosted setups
• Coil pack failures occasionally

⭐ Quick Summary

• The FA20 was used in 86/BRZ and WRX (turbo version).
• FA20 comes in two types: NA (FA20D) and Turbo (FA20F).
• Power ranges from 197–205 hp (NA) to 268+ hp (Turbo).
• Common mods: header + tune, E85, exhaust, supercharger/turbo kits.
• Successor engine is FA24D (2.4 NA) in the 2022+ GR86/BRZ.

🔥 FA20D vs FA20F — Complete Technical Comparison

1. Engine Type & Application

Spec	FA20D	FA20F
Aspiration	Naturally Aspirated	Turbocharged
Cars	Toyota 86 / GT86 / GR86 (pre-2022) Subaru BRZ Scion FR-S	Subaru WRX (2015- 2021) Subaru Forester XT (2014- 2018)
Compression	12.5:1	10.6:1
Injection	Dual (port + direct)	Dual (port + direct)
Target purpose	Light RWD sports car	AWD turbo performance / utility

⚡ 2. Power & Torque

FA20D — NA

• 197–205 hp @ 7000 rpm
• 151–156 lb-ft torque
• High compression, rev-happy, linear
• Weakness: mid-RPM torque dip

FA20F — Turbo

• 250–268 hp stock (some JDM trims ~300 hp)
• 258–270 lb-ft torque
• Big low-end torque, easy tuning gains

🧨 3. Driving Feel

FA20D

• Requires high revs for power
• Light footwork, sharp throttle
• Best suited for track & corners
• Torqueless below 4,500 rpm without mods

FA20F

• Accessible power everywhere
• Pulls strongly from 2,000 rpm
• Better for highway, daily, drag, and tuning
• More flexible in gear selection

🔧 4. Reliability Comparison

FA20D Reliability (BRZ/86)

Pros:

• Simple (no turbo) → less heat
• Strong bottom-end up to ~300 hp

Cons:

• Early oil consumption (2012–2014)
• Valve spring recall issues
• High oil temps on track
• Injector seals fail when boosted

Safe limit on stock internals:

• NA: unlimited
• Turbo/supercharged: 250–300 hp (safe)
• 330–350 hp (risk zone)

FA20F Reliability (WRX/FXT)

Pros:

• Built for boost → stronger pistons than FA20D
• Good coolant/oil flow for turbo layout

Cons:

• Ringland failures when tuned too aggressively
• Turbo heat + oil coking if poor maintenance
• Carbon buildup (DI engine)
• Head gasket seepage on high mileage units

Safe power range:

• 300–330 hp = very safe
• 350–380 hp = moderate risk
• 400+ hp = forged pistons required

⚙️ 5. Common Mods for FA20D (BRZ/86)

Most effective mods (real gains):

1. Headers (UEL or EL)

• Eliminates torque dip
• +10 to +25 hp
• Best single mod for the car

2. ECU tune (EcuTek, OFT, Delicious)

• Required after headers
• Gains +8 to 15 hp
• Sharper throttle & better torque curve

3. E85 / Flex-fuel tuning

• +20–30 hp
• Massive torque improvement
• Requires flex-fuel kit + tune

4. Oil cooler (important for track)

• Reduces oil temps by 15–25°C
• Protects engine longevity

5. Forced induction

• Supercharger kits: HKS, Jackson Racing, Sprintex
• Turbo kits: Full Blown, AVO, Greddy
• Power range: 250–350 hp

⚙️ 6. Common Mods for FA20F (WRX/FXT)

Stage 1 Tune

• +20–30 hp
• +40–60 lb-ft
• No hardware needed

Downpipe + Tune (Stage 2)

• +40–60 hp
• Faster spool
• Bigger mid-range torque

Top-mount or front-mount intercooler

• Lower intake temps
• Prevents power loss on hot days

Turbo upgrades

• Popular choices: Blouch, Tomei, FP Blue
• Can reach 350–400+ hp with fueling upgrades

Supporting mods

• J-pipe
• Charge pipes
• TGV delete
• Boost control solenoid
• Oil catch can / AOS

🥇 Which engine is better? (Verdict)

If you want: Pure driving feel / high RPM / lightweight track car → FA20D

✓ Great with header + tune

✓ Better balance & lightweight

✓ More reliable when NA

If you want: Power / easy tuning / daily torque → FA20F

✓ Gains 30–80 hp easily

✓ Strong mid-range

✓ Much faster in real-world driving