The Race Stage 1 and Race Stage 2 head packages both include a complete freshening of the cylinder heads. Heads are fully disassembled, cleaned, and inspected prior to CNC porting. All components in the valvetrain are replaced with the best offerings from Ferrea. The 1mm oversized Competition Plus valves, bronze valve guides, seals, dual valve springs, seat locators, valve locks, and titanium retainers assure you are getting the best combination of performance and reliability.
The CNC porting optimizes the intake and exhaust ports for increased airflow, which improves power, torque, and boost response. A big advantage to CNC porting vs hand porting is consistent results with equal flow in all ports, every time. HP gains will vary based on many variables, but a Stage 1 head package with our GT1R camshafts will generally pick up in the neighborhood of 75-125hp while improving response and widening the powerband considerably.
The Race Stage 1 package has been run to over 9,500rpm and 2,000hp and is what we use in most of our GT1R Long Block packages. For people looking to push the absolute limits of VR38 based performance, the Race Stage 2 heads are exactly what you need. In addition to the modifications and parts in the Stage 1 heads, we replace both the intake and exhaust seats with a custom beryllium copper valve seat.
All cylinder head packages require cores to be supplied or a core charge will be added for a new pair of heads and cam buckets.
Both packages include setting valve lash if cams are supplied or purchased with the cylinder heads. We offer/recommend our GT1R camshafts for most applications ranging from 800-2,500hp.