Skunk2 Ultra Series Street K20A/A2/A3 K24 Engines Intake Manifold307 05 0600 The much anticipated Ultra "Street" Intake Manifold for the '02 '05 Civic Si and '02 '06 RSX RSX Type S, and or any swap using the K20A K20A2 K20Z1 K24A1 engines or cylinder heads has finally arrived! The Ultra Series is years of research and development, culminated in a multi piece cast aluminum intake manifold that offers advantages that only a modular design could allow. Using the latest in CFD (Computational Fluid Dynamics) software;