CP Pistons & Rings 99.75mm Bore 8.2 Comp +.25mm Size WRX / STI Subaru EJ255 / 257 2.5L Turbo Models 2004-2021

Part #: SC7422. CP forged pistons for WRX and STI offer amazing ring seal, higher vacuum, less blow - by, great durability, and more horsepower and torque across the power band. The peak horsepower stays strong throughout the life of the piston rings, thanks to lightweight forgings and CP's unique machining. CP is all about top - notch engineering, using the latest forging and CNC techniques with strict quality control, which ensures a high - performance and reliable product every time. CP has some of the best quality control standards in the industry. It's part of Pankl Racing Systems, a high - tech racing group supplying parts to big - name teams and companies like Ferrari and Porsche. You won't find a better piston for your EJ20 or EJ257. CP also offers optional coatings. The top coating reflects heat into the combustion chamber, increasing exhaust gas speed and scavenging. The skirt coating provides extra lubrication in extreme heat or heavy wear, reducing friction. Coating options are for the whole set and add 4 - 6 weeks to the order time. Piston features include high - strength aluminum forgings, super lightweight design, fully CNC machined and balanced to +/- 1 gram, an accumulator groove, double pin oilers force - fed from the oil ring, and wrist pins are included.

Using these CP pistons and rings is straightforward. First, make sure your engine is properly prepped and clean before installation. Carefully place the pistons in the cylinders according to the orientation markings. Don't forget to lubricate the pistons and rings well before fitting them. When it comes to running the engine after installation, let it warm up gradually during the initial runs. This helps the pistons and rings to seat properly. For maintenance, regularly check the engine oil level and quality. If you've opted for the coated pistons, be aware that they might require a bit more careful running - in. If you notice any strange noises or performance drops, it's a good idea to check the pistons and rings right away. Also, remember that the coated option adds 4 - 6 weeks to the order time, so plan your project accordingly.