Brand new release from TR Performance is our T3 cast turbo manifold for the 06+ Honda Civic Si! Fits 2 and 4 door with the K20 iVTec engine. Manifold excepts external 35 or 38mm wastegates, and any T3/T4 turbo. Treadstone manifolds are cast using a high ductile silicone based iron adhering to a strict ASTM casting standards. These manifolds are very durable and will withstand all the heat and vibration you can throw at them. Our manifolds casting exceeds OEM specifications and now come with lifetime warranty against cracking(veiw tech page for additional warranty info). All internal surfaces are cast smooth for high flow and low surface friction. The manifold is coated with a high temp paint which deters any corrosion and rust!