FA20 HKS 2.1L Stroker Kit (High Compression)



FA20 HKS 2.1L Stroker Kit (High Compression) – 21004-AT002

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 who 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 optimization of compression ratio for flexibility of setup and high boost use.
  • Piston crown had 3D design in consideration of the stock direct injection system.
  • Stock pistons skirts overhang from the block during the 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 crankpin 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 meticulous 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.
StockHKS 2.1L
PistonBore dia. mm8686
Displacement cc1998.22091.2
Comp. Ratio (measured)G/K 0.5 mm12.112.4
G/K 0.6 mm1212.3
G/K 0.7 mm11.912.1
G/K 1.0 mm11.511.8
RemarksCast D. ignitionForged D. ignition
Con’rodBig end dia.5351 (RB & SR)
Bolt sizeM9.5M8
RemarksSplit I-beamSplit I-beam
CrankshaftStroke mm8690
Main journal dia.6868
Pin journal dia.5048


Test vehicle
VehicleBRZ(ZC6) Kansai demo car
SuctionHKS Premium Suction
Exhaust ManifoldKansai original
Front PipeKansai original
Exhaust systemHKS Hi-Power Spec L
Fuel PumpStock
CPUKansai original ECU
OtherBig 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.

For info on FA20 HKS 2.1L Stroker Kit (High Compression) please go here

For info on our full range of goods and services please go here