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Capacity Upgrade Kit for FA20

Capacity Upgrade Kit developed by taking advantage of knowledge and experience acquired through D1 drift and time attack at Tsukuba Circuit.
This kit was designed exclusively for the FA20 engine by meticulous analysis and experiment. HKS delivers this kit with "Made in Japan" quality.
High performance specifications withstanding 550(ps)-50(kgf・m)!
This kit is for people want to upgrade all the way including the engine internals.



  • Carefully selected specially forged raw materials used.
  • Replacing the gasket enables both NA and turbo-charged engine users to use this kit.
  • In order to cope with the demands of high outputs, strength analysis and tests have allowed optimisation of compression ratio for flexibility of setup and high boost use.
  • Piston crown had 3D design in consideration of stock direct injection system.
  • Stock pistons skirts overhang from the block during bottom of travel. Short height pistons have revised potential issues in this area.
  • Friction, weight and other design properties to suit the needs of short height pistons.


  • Specific connecting rods have been designed to suit the longer stroke.
    With no engine modifications, a special size crank pin has been set requiring new bearings.
    ※The crank metals (Nissan RB26 & SR) must be purchased separately.
  • High strength I beam design and revised connecting rod bolt size.


  • Made from HKS special forged material
  • Perfect pin journal size was selected by merticulous analysis and experiment for extended stroke.
  • Carefully designed weights balance the engine for maximum efficiency.

POINT-4: Stock Bore Compatible 86.0mm

  • In order to maintain the engine block strength, the stock bore size is maintained meaning there is no need for cylinder liners
  • Reduces the cost of installation as liners, bore & hone and block facing processes are unnecessary.
  Stock HKS 2.1L
Piston Bore dia. mm 86 86
Displacement cc 1998.2 2091.2
Comp. Ratio
G/K 0.5 mm 12.1 12.4
G/K 0.6 mm 12 12.3
G/K 0.7 mm 11.9 12.1
G/K 1.0 mm 11.5 11.8
Boring/Horing - n/n
Remarks Cast D. ignition Forged D. ignition
Con'rod Big end dia. 53 51 (RB & SR)
Bolt size M9.5 M8
Remarks Split I-beam Split I-beam
Crankshaft Stroke mm 86 90
Main journal dia. 68 68
Pin journal dia. 50 48
Remarks Forged Forged


Test vehicle
Vehicle BRZ(ZC6) Kansai demo car
Engine FA20
Transmission 6MT
Parts Specification
Suction HKS Premium Suction
Exhaust Manifold Kansai original
Front Pipe Kansai original
Exhaust system HKS Hi-Power Spec L
I/J Stock
Fuel Pump Stock
CPU Kansai original ECU
Other Big throttle

2.1L kit + Camshaft were tested on Kansai Service's demo car with NA engine.
This graph shows before & after installation.

Upgrading the capacity exceeds the stock engine power in whole power range.
Power increase continues to the high rpm range by using the camshaft together with 2.1L Kit.

Test supported by Kansai Service.

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