Add even more horsepower to your high powered Subaru by upgrading your Pistons. Horsepower Direct carries a growing selection of Forged Pistons including Wiseco, CP Pistons, JE Pistons, Arias and all so you can make more power. Whether you have a 2015 WRX or a EJ205 WRX, bulletproof of set of forged pistons that can handle a lot more power and allow upgrades such as a Subaru Intercooler or bigger Turbocharger.
EJ205, EJ255, EJ257, and FA20DIT
*Please see product pages for any exceptions.
Subaru Ringland failures is a topic I have wanted to write about for quite a long time but I haven’t found the time until now to really put “pen to paper” as they say. This is probably one of the most controversial topics that makes its rounds throughout the Subaru community. There are a lot of theories and discussions on what causes these failures. These include things like poor design, weak components, abuse, fuel line routing etc. With so many opinions it can be difficult to really weed through everything and get an idea of what steps you can take to reduce the risk of having a ringland failure. I do not in any way claim to be a guru or that I have the 1 size fits all answer to this. But over my many years involved in the Subaru community and helping customers build their cars or rebuild after a failure I feel that it’s important to share my thoughts and experience.
For those who don’t know a ringland failure is usually as simple as a crack in the part of the piston that your piston rings “sit” on. This in turn causes a loss in compression in that cylinder with symptoms of misfiring, smoking etc. In it’s worst form if you get 2 cracks on a piston it can eventually break a chunk away and damage the cylinder walls.
The following table has details on a few of the commonly modified Subaru engines:
|Head Type||US WRX||SpecC||US WRX||US STI||EU STI|
|Crank Stroke (mm)||75||75||79||79||79|
|Rod Length (mm)||130.43||130.43||130.43||130.43||130.43|
|Piston Pin Offset (mm)||.3289||.3159||.3088||.3088||.3088|
|Deck Height (mm)||201||201||201||201||201|
|Gasket Thickness (mm)||0.8||0.8||0.8||0.8||0.8|
|Head Volume (cc)||51||50||51||57||50|
|Piston Dish (cc)||12||8||24||22||22|
|Piston Deck (mm)||0.38||1.48||0.39||0.39||0.39|
|Total Quench Height (mm)||0.98||2.08||0.99||0.99||0.99|
|Total Quench Volume (cc)||8.51||13.83||7.70||7.70||7.70|
|Total Deck Volume||18.51||19.83||29.70||29.70||29.70|
|Swept Volume (cc)||498.57||498.57||614.25||614.25||614.25|
|Compresses Volume (cc)||89.51||89.83||85.31||83.00||79.70|
|Static Compression Ratio||8.17:1||8.14:1||8.4:1||8.2:1||8.71:1|
|Rod to Stroke Ratio||1.74||1.74||1.65||1.65||1.65|
|Engine Displacement (cc)||1994||1994||2457||2457||2457|