EJ25 Stage 1

P2P Stage 4 FA20 WRX SB

Product information


Our Stage 4 motor is a continuation of our popular FA engine platform. The major upgrades between our Stage 3 and Stage 4 FA Engine is the upgraded I Beam rods, ARP Case Bolts, Billet Crankshaft, 14mm Headstuds and the O-Ring Headgasket. This is the engine we built for multiple 1000+ HP builds that are still running after years of service. Through years of R&D, and numerous 9 second ¼ mile passes, we have found a recipe for longevity and high HP in the FA platform. Our goal is to provide the customer, you, with entry to a level of engine building normally found in super cars and race teams. Our goal is your success, we are not afraid of any problem, and will assist you with any questions.

Additional details

Engine Highlights

  • Designed for up to 40+psi, 1000+BHP and 8,200rpm
  • Closed Deck – Single Piece Billet with Improved Cooling Channels
  • Upgraded Pinned Mains
  • Machined Oil Galley for Improved Main Oiling
  • 14mm Headstuds
  • O-Ring Groove Added for Additional HG Seal-ability.
  • Seasoned Subaru OEM Case Halves precisely bore honed and align honed to exacting dimensions.
    • Some manufacturers simply buy case halves from Subaru and drop parts in, that’s not what we do. The pistons are precisely measured and numbered for each bore. The bores are then honed to exactly the right size.
    • We also align hone the mains to be within 0.0001” of nominal spec.
  • CP Pistons with Upgraded Ring Packs
  • Manley Turbo Tuff I-Beam Forged Rods or Callies Ultra I-Beams Rods w/ ARP625+ bolts
  • Clevite Coated, ACL, or King Race Bearings for rods and mains.
  • Manley or Callies Billet Crankshaft
  • ARP Case Bolts
  • Rear Cover and Oil Galley Plugs Come Standard

Why Choose our Stage 4 Head Package Over the Competition? All machining, cleaning, and assembling are done by a degreed engineer. We provide a level of artisan craft in our engines only found in race teams and super cars. The experience we bring to our engine program is unparalleled in the industry. We blueprint the entire assembly of the motor to within .0002 of our specs. It is incredibly important to balance your motor to increase the life of your bearings. It is highly recommended to run a Fluidampr/ATI crank pulley or OEM. Do not run an aftermarket solid crank pulley. All of our inspection equipment is high quality, either from Starrett or Mitutoyo, and is sent off yearly for calibration to a qualified cal-lab.