CP Piston & Ring 100mm Bore 8:2 CR WRX / STI Subaru Turbo EJ255 / EJ257 Models 2004-2021

Part #: SC7421. CP's forged pistons for WRX and STI models are a game - changer. They offer excellent ring seal, high vacuum, low blow - by, and great durability. You'll enjoy more horsepower and torque across the power band, and the peak horsepower stays strong throughout the life of the piston rings. Thanks to lightweight forgings and CP's unique machining methods, these pistons are top - notch. CP is all about superior engineering. Using the latest forging techniques, CNC machinery, and strict quality control, they produce high - performance and reliable pistons. CP has some of the highest quality standards in the industry and is part of Pankl Racing Systems, a high - tech racing group that supplies parts to big names like Ferrari and Porsche. You won't find better pistons for your EJ20 or EJ257. CP also offers optional coatings. The top coating reflects heat into the combustion chamber, increasing exhaust gas velocity and scavenging potential. The skirt coating provides extra lubrication in extreme heat or heavy wear, reducing friction on the skirt. 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 in your Subaru WRX or STI is straightforward. First, make sure your engine is in good condition and clean before installation. Follow the standard engine assembly procedures provided by your mechanic or the engine's manual. When it comes to the optional coatings, keep in mind that they take 4 - 6 weeks to be applied. So, plan your order accordingly. During normal use, pay attention to your engine's performance. If you notice any unusual noises or changes in power, it could be a sign of an issue. For maintenance, regular oil changes are crucial. The pistons rely on clean oil for proper lubrication. Also, keep an eye on the engine's temperature. Overheating can cause damage to the pistons and the coatings. If you use your car for high - performance driving, more frequent inspections are recommended. Make sure to check the pistons for any signs of wear or damage during routine engine maintenance.