Product Information
Part #: SC7420. CP forged pistons for WRX and STI models offer outstanding ring seal, higher vacuum, lower blow - by, and better durability. They also boost horsepower and torque across the power band, and maintain peak horsepower throughout the piston ring's lifespan. Thanks to lightweight forgings and CP's unique machining methods, these pistons are top - notch. CP is committed to excellent engineering, using the latest forging and CNC techniques, and strict quality control. As a part of Pankl Racing Systems, CP supplies components to many top - level racing teams and elite brands. You won't find better pistons for your EJ20 or EJ257. CP offers optional coatings. The top coating reflects heat into the combustion chamber, increasing exhaust gas speed and scavenging ability. The skirt coating provides extra lubrication in extreme heat or heavy wear, reducing friction. Coating options are applied to the whole set and add 4 - 6 weeks to the order time. Piston features include high - strength aluminum forgings, a super - lightweight design, full CNC machining and balancing to +/- 1 gram, an accumulator groove, double pin oilers fed from the oil ring, and wrist pins.
Using these CP pistons is straightforward. First, make sure your engine is properly prepped according to the Subaru WRX/STI EJ255/EJ257 engine manual. Install the pistons carefully, following the correct orientation. When it comes to the optional coatings, if you choose them, just note that it'll take 4 - 6 weeks longer for your order to arrive. As for maintenance, regularly check the piston rings for wear. Also, keep an eye on the oil level and quality, as the double pin oilers rely on proper lubrication. In extreme heat or heavy - use situations, the skirt coating will help, but still, be cautious. If you notice any abnormal engine noises or performance drops, it's a good idea to inspect the pistons right away.
