Our very own TSM Race Honda/Acura H-Series Turbo Manifolds are designed and manufactured in the USA! Made from high-quality stainless steel, our top-mount manifolds are TIG-welded and back purged to ensure the highest-quality product. Our flanges are machined flat ensuring a perfect seal. The TSM Flanges are produced in our facility from ½” plate 1018 Steel and CNC machined unlike the cheap laser cut flanges on the market. Each stage of manufacturing is passed through our quality control team to ensure the end user gets a top-notch product. This is our best-selling turbo manifold for a reason. The quality and performance sets the bar.