J-Spec Header Outlet Flange Kit

The J-Spec Header Outlet Flange Kit from VIBRANT PERFORMANCE is a precision-engineered collector flange designed for engine builders and automotive enthusiasts upgrading exhaust systems on Japanese-specification vehicles. This stainless steel flange serves as the critical transition point between your custom header and the exhaust system, allowing you to establish a clean, leak-free seal at the collector outlet. Whether you're fabricating a full turbo manifold conversion, upgrading from stock exhausts, or building a street performance engine, this J-Spec flange ensures proper fitment and reliability on modified powerplants.

Machined from natural stainless steel, this outlet flange features a 2.5-inch ID (inside diameter) bore sized for standard header collector piping, with a 0.375-inch thickness that provides structural rigidity while maintaining compatibility with bolt-on header assemblies. The two-bolt configuration uses industry-standard fastener patterns, and the included gasket is pre-selected to handle exhaust temperatures and vibration cycles typical of performance applications. The compact footprint (4.8 × 3.6 × 4.8 inches) and lightweight construction (1.2 lbs) make installation straightforward without adding unnecessary mass to your engine bay.

Mechanics and tuners routinely specify this J-Spec Header Outlet Flange Kit for Honda, Nissan, Subaru, and Mitsubishi platforms where aftermarket header fitment requires a quality collector outlet adapter. It's an essential component when transitioning from OEM or budget headers to custom-fabricated systems, or when replacing damaged flange surfaces. The stainless construction resists corrosion and thermal fatigue, making it ideal for both street and track applications where header temperatures reach 700°F and beyond. Proper installation requires torquing fasteners evenly and seating the gasket firmly to prevent exhaust leaks that compromise scavenging and engine performance.