{"product_id":"tsm-race-k-series-4-1-header-w-megaphone-3-vband","title":"Tsm Race K-series 4-1 Header W\/ Megaphone \u0026 3” Vband","description":"\u003cp\u003e\u003cspan\u003eTSM Race 4-1 K-Series Header with Megaphone \u0026amp; 3\" V-Band\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe TSM Race 4-1 K-Series Header\u003c\/span\u003e\u003cspan\u003e is a performance-focused exhaust upgrade designed for Honda K-Series engines. Its purpose is to improve exhaust gas evacuation, reduce exhaust restriction, and help the engine produce more horsepower and torque, particularly in the mid-to-high RPM range.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThis header is especially appealing for naturally aspirated K-Series builds where maximizing airflow and top-end performance is a priority.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eKey features and performance benefits\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e1. 4-1 Performance Header Design\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe four individual exhaust runners merge into one collector, creating a more direct exhaust path. Compared with a typical factory exhaust manifold, a properly designed 4-1 header can offer:\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eImproved exhaust scavenging at higher RPM\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eReduced exhaust backpressure\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eBetter high-RPM horsepower potential\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eImproved throttle response when properly matched to the engine\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e2. Megaphone Collector\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe megaphone-style outlet is designed to influence exhaust gas velocity and pressure-wave behavior.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003ePotential benefits include improved exhaust pulse tuning, better high-RPM breathing, and stronger top-end power when matched with the appropriate engine setup.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e3. 3-Inch V-Band Connection\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe 3-inch V-band outlet is particularly useful for performance exhaust systems.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eIt provides a secure connection, makes exhaust removal easier, and supports integration with a properly sized 3-inch exhaust system.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e4. Performance-Oriented Construction\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe pictured header features polished metal tubing, welded joints, and a long-tube runner layout.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eIts construction and configuration are intended for performance applications, although the exact stainless-steel grade and tubing specifications should be confirmed with the manufacturer.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e5. Horsepower potential\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eA comparable K-Series megaphone race header is advertised with gains of approximately \u003c\/span\u003e\u003cspan\u003e19–26 horsepower over a stock header on a race-built engine\u003c\/span\u003e\u003cspan\u003e. That is not a verified result for this particular TSM Race header, but it illustrates the potential of this style of exhaust design.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eActual gains depend heavily on engine displacement, camshafts, compression ratio, intake setup, exhaust diameter, and ECU tuning.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThis style of header is particularly well suited to performance K20 and K24 combinations with upgraded camshafts, intake manifolds, and supporting modifications.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eApplication and fitment\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eDesigned for Honda K-Series performance applications, including K20 and K24 engine combinations. Exact vehicle fitment, engine mount compatibility, and chassis clearance should be verified before purchase.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eBottom line:\u003c\/span\u003e\u003cspan\u003e The TSM Race 4-1 Megaphone Header is a promising upgrade for K-Series enthusiasts chasing stronger high-RPM performance, improved exhaust flow, and a more aggressive exhaust note. Its greatest potential is in a properly tuned, naturally aspirated performance build.\u003c\/span\u003e\u003c\/p\u003e","brand":"Black Friday Sale 2026","offers":[{"title":"Default Title","offer_id":68046291042409,"sku":null,"price":449.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0296\/2355\/0057\/files\/6EFC3421-46EC-46FF-8925-15210ADA21D7.png?v=1794431653","url":"https:\/\/onlinetsm.com\/products\/tsm-race-k-series-4-1-header-w-megaphone-3-vband","provider":"Tri-State Motorsports","version":"1.0","type":"link"}