The P&L Motorsports EJ25 P1 CNC Cylinder Head Package for the Subaru WRX and STI is the highest flowing, most horsepower-making cylinder heads available on the market. Used in both our quarter-mile record-setting 8.35 sec & 8.99 sec Subarus, the P&L P1 Cylinder Heads deliver both performance and reliability.
Features:
- Best performing and most developed design on the market
- CNC ported for optimum flow, performance, and consistency across the head
- +1mm valves increase flow and performance
- High heat tolerant Inconel exhaust valves add durability
- Performance valve springs for maximum performance up to 10,000 rpm
- Precisely hand-finished runners, chambers, and blending of the bowl area
- Professionally assembled by P&L Motorsports
- Available on a core exchange or for outright purchase
Applications: All EJ255 and EJ257 equipped Subarus
- 06-14 WRX
- 04-15 STI
- 04-13 Forester XT
- 05-12 Legacy GT
- 05-09 Outback XT
- 04-06 Baja XT
- 05-06 Saab 9-2X
Flow Numbers:
| INTAKE – LIFT | INTAKE – FLOW | EXHAUST – LIFT | EXHAUST – FLOW |
|---|---|---|---|
| .050″ | 62.56 CFM | .050″ | 55.89 CFM |
| .100″ | 106.38 CFM | .100″ | 92.63 CFM |
| .150″ | 154.25 CFM | .150″ | 136.55 CFM |
| .200″ | 196.02 CFM | .200″ | 181.70 CFM |
| .250″ | 238.56 CFM | .250″ | 209.35 CFM |
| .300″ | 269.08 CFM | .300″ | 226.25 CFM |
| .350″ | 286.25 CFM | .350″ | 233.56 CFM |
| .400″ | 301.05 CFM | .400″ | 240.16CFM |
| .450″ | 305.84CFM | .450″ | 243.25 CFM |
| .500″ | 309.87 CFM | .500″ | 247.11 CFM |
CFM: Cubic Feet Per Minute
*We do flow testing down to .050″ because low lift flow and good data resolution are important.*
*Due to the volatile nature of high horsepower racing applications and outside circumstances such as inability to monitor proper break-in, engine oil selection, ancillary mechanical faults, and improper ECU calibration do not allow us to provide a warranty for these assemblies.