JE Pistons and Rings 99.5 Bore 79mm Stroke 8.8:1 Comp Subaru WRX / STI EJ257 BILLET FSR 2004-2021

Part #: 310927. JE Pistons is excited to unveil the first billet racing pistons for Subaru EJ257 engines, fitting your WRX and STI. Originally crafted for high - end race cars like the Crawford Performance Unlimited AWD Time Attack Subaru and Ken Block's Gymkhana racecar, these pistons are now accessible to the public. Machined 100% via CNC from top - notch 2618 - T6 wrought aluminum bar stock, they're tailored for high - horsepower road and drag race engines. The pistons have internal and external bracing to boost durability and strength. Their unique 'donut dish' crown and application - specific under - crown profile manage heat well and reduce stress in high - power Subaru engines. Unlike forged pistons, billet pistons are machined on all surfaces, shedding up to 32 grams of unnecessary weight. They only weigh 392 grams, making them lighter than other aftermarket pistons. High - quality 9310 steel wrist pins and JE Pro Seal Rings are included. For extreme racing, you can upgrade to Diamond Like Carbon (DLC) coated wrist pins. Fitment: SUBARU EJ257 BILLET FSR with a STD Bore of 99.5mm. Features: 100% CNC machined billet piston, designed for high - horsepower Subaru racing engines up to 1200hp, light - weight at 392 grams, made from certified 2618 - T6 aluminum alloy, internal and external strut braces, premium 9310 steel wrist pins with DLC upgrade option, JE Pro Seal Piston Rings (1.2, 1.2, 2.5mm), Tru Arc locks for easy installation, includes 4 pistons and 4 rings.

Using these JE pistons and rings is straightforward. First, make sure your Subaru EJ257 engine is clean and ready for installation. The Tru Arc locks make the pistons easy to install. Just follow the standard engine assembly procedures. For high - horsepower applications, these pistons are a great choice as they're designed to handle up to 1200hp. When it comes to maintenance, keep an eye on the engine's performance. If you notice any unusual noises or a drop in power, it might be time to check the pistons. Regular oil changes are also important to keep the pistons and wrist pins lubricated. If you're using the engine for severe racing, consider upgrading to the DLC coated wrist pins for better performance. Remember, proper installation and maintenance will ensure the longevity and high - performance of these pistons and rings.