subaru performance

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subaru performance
subaru performance  


cylinder head porting
subaru impreza wrx
subaru outback performance
subaru wrx sti
subaru wrx
subaru sti
A properly designed combustion chamber will allow you to run extreme compression ratios on pump gas. Our engineers have over 20 years of experience building successful racing engines. We apply innovative and proven techniques to improve flow in your specific application, increasing power and efficiency without sacrificing reliability.

We offer cylinder porting services for any modern four or five valve head designs, any modern motorcycle, and some two valve heads. Some of the techniques we use are detailed below.

We also redesign combustion chambers by welding and reshaping them. This example is a Datsun L6 E88 head. This engine has 10.6:1 compression ratio and runs on 89 octane pump gas! No gadgetry or trickery, just a properly designed combustion chamber.

All Subaru Cylinder Heads

Stage I Cylinder Head Porting

  1. Port refinishing and bowl contouring
  2. Custom 5-angle Valve Seat Machining
  3. Hand Blending of the Port/Valve Seat Juncture
  4. Combustion Chamber Cleaning
  5. Exhaust port balancing
  6. Milling of the cylinder head (depth is appropriate for application and combustion chamber work)

Stage II Cylinder Head Porting includes above plus:

  1. Graduated intake port finishing
  2. Exhaust Port polishing
  3. Combustion Chamber modifications, measurement and matching of combustion chamber volumes, polishing, and valve un-shrouding

Stage III Cylinder Head Porting includes above plus:

  1. Intake port redesign
  2. More extensive exhaust port modifications
  3. Flow bench testing

*Note1: All Cylinder Head Porting is custom tailored to the individual customer needs. 

 *Note2: Porting for Turbocharged and Supercharged applications have more significant modifications performed on the combustion chamber and exhaust ports, while less work is done on the intake ports so as to properly balance flow.

Flow Bench Data


Description Unit # Price (US)
Cylinder Head Porting All Models    
Stage I Porting   $ 1499
Stage II Porting   $ 1999
Stage III Porting   $ 2699
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