CP Forged Pistons Fits Subaru EJ255 WRX 8.5:1 EJ257 STI 8.2:1 99.5mm SC7420
Description
This is a full set of Pistons, Rings, Pins, and Locks
This piston is designed to be used with a standard-stroke Crank in an EJ257 block with a standard-length connecting rod. This combination works out to a 2.5L depending on bore size.
Compression Ratio:
This piston maintains the standard compression ratio.
Bore Size:
This piston is designed to work with the standard bore. However, there are a couple things you need to know as the buyer before deciding to purchase standard bore pistons. Many people purchase standard-bore pistons before ever taking their engine apart, with the plan being that they are hoping to avoid a machine-shop bill by just getting a standard bore piston and dropping them in. Many times, the engine then comes apart for the machine shop to find out that the cylinder walls are not true, and need to be bored out to the next size up to expose a clean surface. Thats when we get the phone-call from the customer asking to swap the pistons out. Avoid the headache, the delay, and the exchange-fee by having your block inspected before you purchase the pistons. That way you get the right parts the first time. Our shipping times are extremely fast and we will get the pistons to you quicker than anyone in the industry because we understand that every day your engine is apart, is another day you are not driving it. If you are unsure what size you need, and you want to order the pistons before the engine is apart, you would be better off playing it safe and just buying over-sized pistons and letting the machine shop bore the block to the pistons. You can't go wrong with that strategy.
File to Fit Rings:
These pistons come with file-to-fit rings. This means the rings come slightly-long, and MUST be filed to the desired ring-gap for your application. This ring gap can vary depending on what your engine will be used for. For example, a 1000hp drag-only application will have a much different ring gap than a 300hp daily driven engine. Consult with your engine builder before filing your rings, and do not install the rings without filing them.
These pistons, like many aftermarket pistons, are made of 2618 alloy. 2618 is a strong, durable, forged aluminum alloy that can withstand a large amount of abuse in race applications.
Tools:
If you are installing these pistons yourself, there are some tools you will need to install them in your engine correctly. We can help supply you with these tools if you don't already have them. At the very minimum you will need a quality torque wrench and a ring compressor. You should also get a quality bolt-stretch gauge to properly torque your rod bolts. Please see the supporting mods section of this page to add these tools to your shopping cart.
Note: This is a full set of Pistons, Rings, Pins, and Locks
Car Make: Subaru
Car Model: Impreza WRX / WRX STi
Years: 2004-2018 STi / 2006-2014 (WRX)
Engine: EJ255 / EJ257
Included Ring Set: RS1658-3917-0
Compression Ratio: 8.2:1 STi / 8.5:1 WRX
Face Type: Dish
Dome CC: -21 cc
Head CC: 56 cc
Gram Weight: 392 g
Pin Size: 23mm
Compression Height: 1.208"
Rod Length: 130.5mm
Stroke: 79mm
Bore: 99.5mm
Material: 2618 Alloy
Bore Size: STD
Standard Pin (Included): 905-2500-18CP1S
Upgraded Pin (Not Included): 905-2500-26CP3S
Pin Locks (Included): 905x055 SUB
Ring Part#: RS1658-3917-0
This piston is designed to be used with a standard-stroke Crank in an EJ257 block with a standard-length connecting rod. This combination works out to a 2.5L depending on bore size.
Compression Ratio:
This piston maintains the standard compression ratio.
Bore Size:
This piston is designed to work with the standard bore. However, there are a couple things you need to know as the buyer before deciding to purchase standard bore pistons. Many people purchase standard-bore pistons before ever taking their engine apart, with the plan being that they are hoping to avoid a machine-shop bill by just getting a standard bore piston and dropping them in. Many times, the engine then comes apart for the machine shop to find out that the cylinder walls are not true, and need to be bored out to the next size up to expose a clean surface. Thats when we get the phone-call from the customer asking to swap the pistons out. Avoid the headache, the delay, and the exchange-fee by having your block inspected before you purchase the pistons. That way you get the right parts the first time. Our shipping times are extremely fast and we will get the pistons to you quicker than anyone in the industry because we understand that every day your engine is apart, is another day you are not driving it. If you are unsure what size you need, and you want to order the pistons before the engine is apart, you would be better off playing it safe and just buying over-sized pistons and letting the machine shop bore the block to the pistons. You can't go wrong with that strategy.
File to Fit Rings:
These pistons come with file-to-fit rings. This means the rings come slightly-long, and MUST be filed to the desired ring-gap for your application. This ring gap can vary depending on what your engine will be used for. For example, a 1000hp drag-only application will have a much different ring gap than a 300hp daily driven engine. Consult with your engine builder before filing your rings, and do not install the rings without filing them.
These pistons, like many aftermarket pistons, are made of 2618 alloy. 2618 is a strong, durable, forged aluminum alloy that can withstand a large amount of abuse in race applications.
Tools:
If you are installing these pistons yourself, there are some tools you will need to install them in your engine correctly. We can help supply you with these tools if you don't already have them. At the very minimum you will need a quality torque wrench and a ring compressor. You should also get a quality bolt-stretch gauge to properly torque your rod bolts. Please see the supporting mods section of this page to add these tools to your shopping cart.
Note: This is a full set of Pistons, Rings, Pins, and Locks
Car Make: Subaru
Car Model: Impreza WRX / WRX STi
Years: 2004-2018 STi / 2006-2014 (WRX)
Engine: EJ255 / EJ257
Included Ring Set: RS1658-3917-0
Compression Ratio: 8.2:1 STi / 8.5:1 WRX
Face Type: Dish
Dome CC: -21 cc
Head CC: 56 cc
Gram Weight: 392 g
Pin Size: 23mm
Compression Height: 1.208"
Rod Length: 130.5mm
Stroke: 79mm
Bore: 99.5mm
Material: 2618 Alloy
Bore Size: STD
Standard Pin (Included): 905-2500-18CP1S
Upgraded Pin (Not Included): 905-2500-26CP3S
Pin Locks (Included): 905x055 SUB
Ring Part#: RS1658-3917-0
Manufacturer Product Specifications
CP Standard Shelf Pistons
Features
- Dedicated forgings
- Balanced to + or 1 gram
- Wrist pins provided at no cost
- Pin fitting provided at no cost
- Accumulator Grooves
- Dual forced pin oilers
- Pick lock grooves
- Fully CNC machined
- USA Made
Pistons come with wrist pins, pin fitted, and locks.
CAM AND BARREL
The Cam is the shape around the skirt of the piston and the barrel is the shape from under the oil ring to the bottom of the skirt. Extensive research and development has been done to find the optimum skirt shape for each piston. These shapes have been found to seal up cylinders and reduce harmonics in the bore better than ever before. Depending on the forging and application, different cam and barrel profiles are utilized for maximum performance. Having the correect cam and barrel on a part promotes the following:
1. Tighter clearances
2. Less noise
3. Better ring seal
4. More power
5. Increased durability
ANTI DETONATION GROOVES (CONTACT REDUCTION GROOVES)
Also know as contact reduction grooves, which limit the piston/cylinder contact during high temperature and high RPM. These grooves also protect the top ring by disrupting detonation waves.
ACCUMULATOR GROOVE
V-shaped groove machined in the 2nd ring land that adds to the volume between the top and second ring. This groove accumulates residual gasses from combustion which alleviates top ring flutter and premature second ring wear, improving ring seal.
DOUBLE PIN OILERS
Double Pin Oilers (opposed to single pin oilers), in conjunction with our annular reservoir, can add twice the amount of oil from the cylinder wall to the wristpin bore. This is a standard option on any piston that receives forced pin oiling.
BROACHES
Broaches are horizontal slots in the pinbore designed to allow oil to enter between the wristpin and pinbore. Broaches are also used to accommodate the wristpin shape under compression, as it can become somewhat oval and needs room in order to alleviate galling.
PIN FITTING
The pin bore is precision honed to attain an exact pin clearance. Depending on the application clearances typically range from .0003 to as much as .003 between the wristpin and pin bore.
Payment
Almost all of our eBay Listings are "Buy it Now" which means payment is due immediately at the time of purchase.
Return Policy: We allow returns of unopened product within 30 days of the purchase date for a money-back refund. If the original packaging is missing or damaged, or if it has been longer than 30 days since you purchased the item, there may be restocking fees incurred. Please message us for a Return Authorization Number before sending anything back to avoid processing delays.
Return Policy: We allow returns of unopened product within 30 days of the purchase date for a money-back refund. If the original packaging is missing or damaged, or if it has been longer than 30 days since you purchased the item, there may be restocking fees incurred. Please message us for a Return Authorization Number before sending anything back to avoid processing delays.
AbouT us
Real Street Performance is unlike most "Race Shops". We are a fully functioning wholesale and retail distribution warehouse in addition to a dyno-equipped tuning and engine building facility. Our sales center and order fulfillment center operates with state of the art, industry leading software that allows us to get you ALL of the parts you need for your build quickly and correctly the first time without the headaches or excuses.
- Best Pricing
- Fast Shipping
- Immediate Response Time
- Experienced in International Export
- 100% Positive Customer Satisfaction Feedback Rating
- Best Pricing
- Fast Shipping
- Immediate Response Time
- Experienced in International Export
- 100% Positive Customer Satisfaction Feedback Rating
Shipping Info
WE CAN ONLY SHIP TO THE ADDRESS ENTERED DURING CHECKOUT.
Most domestic orders ship within 5 days, please allow up to 7-10 days for international orders to ship.
We are very familiar with International Export procedures and we ship out of the country every day. If you are a customer outside of the United States of America, have no worries, we will get your parts to you quickly and correctly, many times just as quickly as our domestic shipments.
Some shipping destinations will require additional shipping, these customers will be contacted immediately after placing their order. Feel free to contact us before placing your purchase for an exact shipping quote.
Import Duties, Taxes, and Charges are not included in the item price or shipping cost. These charges are the buyer's responsibility. Please check with your country's customs office to determine what these additional costs will be prior to bidding or buying.
Quoted shipping does not include insurance. If you would like to add insurance to your contact us here to go over the options.
Please note that eBay requires all orders $750.00 and above to have Signature confirmation, so if your package total is $750.00 or more, your shipment will require a signature.
Even though we are based in Florida, not all orders ship complete from our Florida location. Please be aware that some parts will ship directly from other states to your location. Please message us before clicking buy-now to check location availability if this is a concern of yours.
PLEASE NOTE, ORDERS TO THE FOLLOWING COUNTRIES WILL BE SHIPPED VIA USPS INTERNATIONAL TO AVOID DELAYS AND COMPLICATIONS, UNLESS SPECIFICALLY REQUESTED BY THE BUYER TO SHIP VIA UPS:
- Russia
- Brazil
- Greece
Most domestic orders ship within 5 days, please allow up to 7-10 days for international orders to ship.
We are very familiar with International Export procedures and we ship out of the country every day. If you are a customer outside of the United States of America, have no worries, we will get your parts to you quickly and correctly, many times just as quickly as our domestic shipments.
Some shipping destinations will require additional shipping, these customers will be contacted immediately after placing their order. Feel free to contact us before placing your purchase for an exact shipping quote.
Import Duties, Taxes, and Charges are not included in the item price or shipping cost. These charges are the buyer's responsibility. Please check with your country's customs office to determine what these additional costs will be prior to bidding or buying.
Quoted shipping does not include insurance. If you would like to add insurance to your contact us here to go over the options.
Please note that eBay requires all orders $750.00 and above to have Signature confirmation, so if your package total is $750.00 or more, your shipment will require a signature.
Even though we are based in Florida, not all orders ship complete from our Florida location. Please be aware that some parts will ship directly from other states to your location. Please message us before clicking buy-now to check location availability if this is a concern of yours.
PLEASE NOTE, ORDERS TO THE FOLLOWING COUNTRIES WILL BE SHIPPED VIA USPS INTERNATIONAL TO AVOID DELAYS AND COMPLICATIONS, UNLESS SPECIFICALLY REQUESTED BY THE BUYER TO SHIP VIA UPS:
- Russia
- Brazil
- Greece
Our Services
20,000 sqft Facility in Sanford, FL Our new facility is located in sunny Sanford Florida, but we ship all over the world every day with the most competitive rates.
