Subaru FA engine
Overview
ManufacturerSubaru
Production2012–present
Layout
Displacement
  • 2.0 L (1,998 cm3) (FA20)
  • 2.4 L (2,387 cm3) (FA24)
Cylinder bore
  • 86 mm (3.39 in) (FA20)
  • 94 mm (3.70 in) (FA24)
Piston stroke86 mm (3.39 in)
ValvetrainDOHC 4 valves x cyl. with AVCS
Compression ratio10.6:1, 12.5:1
RPM range
Max. engine speed6700–7400 rpm
Combustion
TurbochargerOptional with intercooler
Fuel systemFuel injection, Direct injection
Fuel typePetrol/gasoline
Cooling systemWater-cooled
Output
Power output200–300 PS (147–221 kW; 197–296 hp)
Torque output205–400 N⋅m (151–295 lb⋅ft; 21–41 kg⋅m)
Chronology
PredecessorSubaru FB engine (parent)

The Subaru FA engine is a gasoline boxer-4 engine used in Subaru and Toyota automobiles. It is a derivative of the FB engine, with efforts to reduce weight while maintaining durability as the main design goals. Although the FA and FB engines share a common platform, the FA shares very little in dedicated parts with the FB engine, with a different block, head, connecting rods, and pistons.

Development

The FA series engine was developed for the Subaru BRZ and the first FA engine, the FA20D, was designed to be mounted as low as possible and to minimize the polar moment of the chassis to improve dynamic response and handling.[1][2] The FA engine features a shallower oil pan and shorter intake manifold to reduce overall engine height compared to the Subaru FB engine.[3] The FA and FB engines share few parts.[2]

A direct injection-only turbo variant of the FA20, the FA20F, was introduced in late 2012 with the 2012 Legacy GT (for the Japanese market) and in the United States, the 2014 model year Subaru Forester. Compression ratio for the turbo engine falls to 10.6:1 from 12.5:1 for the FA20D. A revised variant of the FA20F was introduced for the 2015 model year Subaru WRX; in this application, the camshafts, rocker arms, boost pressure, intercooler, and exhaust were revised to increase peak output.[4]

FA20

Compared to the FB20 engine, which is undersquare with an 84 mm × 90 mm (3.31 in × 3.54 in) bore and stroke for 2.0 L (1,995 cm3) swept displacement, the FA20 is perfectly square with an 86 mm × 86 mm (3.39 in × 3.39 in) bore and stroke for 2.0 L (1,998 cm3) swept displacement. The 86 mm (3.39 in) bore and stroke are also reminders of the heritage Toyota model AE86.

Common parameters for all FA20 variants

FA20D

Subaru FA20D

The FA20D features both direct and port injection (Toyota's D-4S injection system) and Subaru AVCS variable valve timing system. It is used in the Subaru BRZ, and is identified by a Toyota engine family code known as the 4U-GSE, which is installed in the Toyota 86 and the Scion FR-S.[5] According to Subaru, 0W-20 oil is recommended.

Wards Auto put the FA20D on their "10 Best Engines" list for 2013.[6]

FA20F

Subaru FA20F

A version with Subaru's own direct fuel injection and twin-scroll turbocharger was introduced in 2012.[8] Also known as the FA20DIT. The FA20F was named to the Wards Auto "10 best engines" list in 2015[9] and 2016.[10]

FA24

Common parameters for all FA24 variants

FA24F

Subaru FA24F

The FA24F was introduced in 2018 initially for the 2019 model year Subaru Ascent. The bore is increased compared to prior FA20 engines, increasing displacement to 2.4 L (2,387 cm3).[12] The engine has an all aluminum head and block in order to keep weight and warm-up times low.[12] Direct injection and a turbocharger are used to provide output comparable to a 6-cylinder naturally aspirated engine, and the FA24 uses "regular" (87 AKI) fuel.[13] At the 2019 Chicago Auto Show, Subaru unveiled the 2020 model year Subaru Legacy sedan, available starting in fall 2019 and featuring the FA24 as the uplevel engine option.[14] The 2020 model year Subaru Outback also featured the FA24 as the uplevel option.[15]

FA24D

FA24D engine

Like the preceding FA20D, the FA24D uses the Toyota D-4S fuel injection system, which combines direct and port injection. It has the same displacement as the FA24F turbocharged engine with an identical 94×86 mm bore and stroke, but the compression level is increased to 12.5:1.[16][17] Fitting the existing FA24F, with its bottom-mounted turbo, to the second generation Subaru BRZ/Toyota 86 would have required raising the price and overall center of gravity, so natural aspiration was chosen instead. The torque curve was revised, with peak torque coming at a lower engine speed in the FA24D, and without the significant torque decrease between 3,000 and 5,000 RPM exhibited by the FA20D, which resulted from tuning that engine for fuel economy.[18] In addition, an oil cooler has been added to the engine.[19] One important difference is that the 2022 Toyota GR86 engine requires an oil that meets the ILSAC GF-5 standard while the 2023 GR86 engine requires ILSAC GF-6A, while in markets like Australia the 2022 Subaru BRZ still allows ILSAC GF-5 and additionally allows older ACAE A3 and A5.[20][21]

^ The engine is fitted with an additional carbon filter in some regions which slightly restricts the intake.

References

  1. ^ "Subaru BRZ Concept - STI - to Debut at Los Angeles Auto Show" (Press release). Subaru Global. 16 November 2011. Retrieved 28 February 2018.
  2. ^ a b Gall, Jared (December 2011). "2013 Subaru BRZ". Car and Driver. Retrieved 28 February 2018.
  3. ^ "Subaru Unveils "SUBARU BRZ"" (Press release). Subaru Global. 30 November 2011. Retrieved 28 February 2018.
  4. ^ Tate, James (November 2013). "2015 Subaru WRX: Rex Who's Back?". Car and Driver. Retrieved 28 February 2018.
  5. ^ Mark Vaughn. "Subaru shows production version of the BRZ". Autoweek.com. Archived from the original on 2011-12-03. Retrieved 2018-02-28.
  6. ^ Witzenburg, Gary (4 February 2013). "High-Revving Subaru Boxer Engine Is Crowd Pleaser". Wards Auto. Retrieved 28 February 2018.
  7. ^ Jacquot, Josh (October 2016). "2017 Subaru BRZ Manual". Car and Driver. Retrieved 28 February 2018.
  8. ^ "Subaru Legacy and Outback in Japan to Receive Minor Facelift; Fitted with New Generation 2.5 litre NA and 2.0 liter Direct Injection Turbo Boxer Engines" (Press release). Fuji Heavy Industries, Ltd. 8 May 2012. Retrieved 28 February 2018.
  9. ^ Witzenburg, Gary (9 July 2015). "Subaru's Lightweight Boxer Punches Above Weight". Wards Auto. Retrieved 28 February 2018.
  10. ^ Murphy, Tom (7 January 2016). "2016 Winner: Subaru 2.0L Turbocharged DOHC H-4". Wards Auto. Retrieved 28 February 2018.
  11. ^ a b c d "FA20 DIT Engine Specs". Come and Drive It. Retrieved 12 March 2018.
  12. ^ a b Gilboy, James (16 February 2018). "Meet Subaru's new FA24 engine". The Drive. Retrieved 27 February 2018.
  13. ^ "Subaru debuts all-new Ascent 3-row SUV" (Press release). Subaru. 29 November 2017. Retrieved 1 March 2018.
  14. ^ "World Premier of all-new 2020 Subaru Legacy sedan" (Press release). Subaru. February 8, 2019. Retrieved 4 April 2019.
  15. ^ "World Premier of All-New 2020 Subaru Outback" (Press release). Subaru Corporation. April 17, 2019. Retrieved 17 April 2019.
  16. ^ a b "World Premier of All-New Subaru BRZ" (Press release). Subaru Global Media. November 18, 2020. Retrieved 5 April 2021.
  17. ^ a b c d e "～トヨタともっといいクルマづくりを追求し、「誰もが愉しめる究極のFRピュアスポーツカー」へ進化～" [Pursuing better car manufacturing with Toyota, evolving into 'the ultimate FR pure sports car that everyone can enjoy'] (Press release). Subaru Global Media. April 5, 2021. Retrieved 5 April 2021.
  18. ^ Perkins, Chris (November 18, 2020). "Why the 2022 Subaru BRZ Still Isn't Turbocharged". Road & Track. Retrieved 5 April 2021.
  19. ^ Ohto, Yasuhiro (2021). "Japan Premiere 2021: Subaru BRZ" (PDF). Subaru Corporation. Retrieved 5 April 2021.
  20. ^ "What is the GR86 Oil Type, Filter, and Capacity? (2022 and 2023)". SearchForParts. 2023. Retrieved 12 February 2023.
  21. ^ "Oil Brands: What are you running?". GR86.org. 2023. Retrieved 28 June 2023.
  22. ^ "Australian Subaru BRZ Specs". Subaru Australia. Retrieved 13 June 2022.

External links

Wikimedia Commons has media related to Subaru FA engines.

(Japanese: Subaru FA engine)

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