CP Pistons Aluminum Forged Piston Set 92.5mm 8.5:1 C/R Subaru WRX EJ20 WRX 02-05 CP Pistons

CP Standard Features

• Anti-Detonation Grooves:
  Are grooves that protect the top ring by disrupting detonation waves. Also know as contact reduction grooves, these grooves limit the piston/cylinder contact during high temperature and RPM.
• Accumulator Groove:
  Is a V shaped groove machined in the 2nd ring land to collect excess blow-by between the top and second ring. This groove collects residual gasses during combustion and alleviates top ring flutter while increasing ring seal.
• CP groove:
  stands for Constant Pressure Groove. This groove works as a channel on the lower part of the top land that equalizes pressure to the back of the top ring groove. When used in combination with lateral gas ports, the CP groove helps keep gas ports clear of carbon build up. In addition, the CP groove prevents the top land from smudging into the top ring if the land rubs the cylinder bore.
• Double Pin Oilers:
  in conjunction with their dual fed reservoir add twice the amount of oil from the cylinder wall to the wrist pin.
• Cam and Barrel:
  Extensive research and development has been done to find the optimum skirt shape for each piston. Having the correct cam and barrel on a part promotes the following: Tighter clearances, Less noise, Better ring seal, More power, Durability. Depending on the forging and application, different cam and barrel profiles are utilized for maximum performance.

Other Features

• High strength aluminum forging
• Super lightweight designs
• Fully CNC machined and balanced to within +/- 1 gram
• Wrist pins included
• Pin lock grooves for easy lock removal
• Includes piston rings, wrist pins, and circlips