Pro Series Manifold vs. RBC Manifold
- K20A (2.2L)
- 12.5:1 compression ratio
- Skunk2 Stage 2 cams

Variations:
- Solid line: Pro Series Manifold and Pro Series 70mm Throttle Body
- Dashed line: RBC manifold and Pro Series 70mm Throttle Body

The RBC manifold restricts performance significantly once the engine's compression ratio or displacement is increased or once cams are added. Notice the significant gains across the entire powerband on this 2.2L K20A. There is no portion of the powerband that favors the RBC manifold.