{"product_id":"grimmspeed-15-21-subaru-wrx-equal-length-exhaust-header","title":"GrimmSpeed Equal Length Exhaust Header | 2015-2021 Subaru WRX FA20DIT | GRM113008","description":"\u003ch2\u003eGrimmSpeed Equal Length Exhaust Header – 2015–2021 Subaru WRX | FA20DIT | GRM113008\u003c\/h2\u003e\n\u003cdiv style=\"border: 2px solid #cc0000; padding: 12px; margin-bottom: 16px; background-color: #fff5f5;\"\u003e\n\u003cp\u003e\u003cstrong\u003e⚠️ CRITICAL FITMENT — This header fits the 2015–2021 Subaru WRX with the FA20DIT engine ONLY. It does NOT fit the Subaru WRX STI (EJ257 engine). The WRX and STI use completely different engines and headers are not interchangeable. Confirm your model is the WRX (not STI) before ordering.\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border: 2px solid #e6a817; padding: 12px; margin-bottom: 16px; background-color: #fffbf0;\"\u003e\n\u003cp\u003e\u003cstrong\u003e⚠️ ECU TUNE STRONGLY RECOMMENDED — An equal length header significantly changes exhaust flow and scavenging characteristics. A professional ECU tune or reflash after installation is strongly recommended to maximise power gains and ensure proper fuelling. Running without a tune is possible but leaves power on the table and may cause minor running irregularities.\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cp\u003eGrimmSpeed’s equal length exhaust header for the 2015–2021 Subaru WRX (VA chassis, FA20DIT). Replaces the factory unequal length exhaust manifold with an equal length design — improving turbo spool, exhaust scavenging, and peak power. Stainless steel construction, TIG-welded. 16 lbs.\u003c\/p\u003e\n\u003ch3\u003eEqual Length vs. Unequal Length — Why It Matters\u003c\/h3\u003e\n\u003cp\u003eThe stock WRX exhaust manifold is unequal length — the four primary tubes that feed the turbocharger inlet are different lengths, a result of the horizontally-opposed (boxer) engine layout. Unequal length primaries create exhaust pulse timing differences at the turbo inlet, causing pulse interference that reduces scavenging efficiency and contributes to turbo lag. The unequal length design is also responsible for Subaru’s characteristic “burble” exhaust note — a byproduct of the pulse timing, not a designed feature.\u003c\/p\u003e\n\u003cp\u003eAn equal length header makes all four primary tubes the same length, ensuring exhaust pulses arrive at the turbo collector in a consistent, timed sequence. Benefits:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eReduced Turbo Lag:\u003c\/strong\u003e Consistent pulse timing improves turbo spool efficiency — boost builds faster in the mid-RPM range\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eImproved Exhaust Scavenging:\u003c\/strong\u003e Equal-length primaries allow exhaust pulses to assist in drawing spent gases from the cylinders — improving volumetric efficiency\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncreased Peak Power:\u003c\/strong\u003e Better flow and scavenging throughout the RPM range supports higher peak power output, particularly with supporting modifications (intake, tune, intercooler)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLoss of Subaru “Burble”:\u003c\/strong\u003e The characteristic Subaru unequal-length exhaust note is a result of the stock manifold design. An equal length header will produce a smoother, more conventional turbocharged exhaust note. This is an expected and normal outcome, not a defect\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eGrimmSpeed Construction\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eStainless Steel:\u003c\/strong\u003e Primary tubes and collector fabricated from stainless steel for corrosion resistance and heat cycling durability\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTIG-Welded:\u003c\/strong\u003e All joints hand TIG-welded for clean, strong, leak-free construction\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eO2 Sensor Bungs:\u003c\/strong\u003e Factory O2 sensor bung positions retained for compatibility with the factory ECU oxygen sensor inputs\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eEmissions Note\u003c\/h3\u003e\n\u003cp\u003eA performance exhaust header replacing the factory manifold may not be legal for road use in all jurisdictions. Check local emissions regulations before purchasing and installing this product.\u003c\/p\u003e\n\u003ch3\u003eFitment\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e2015–2021 Subaru WRX — VA chassis — FA20DIT engine\u003c\/li\u003e\n\u003cli\u003eDoes NOT fit WRX STI (EJ257)\u003c\/li\u003e\n\u003cli\u003eDoes NOT fit 2022+ WRX (VB chassis)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cem\u003eWRX only — does not fit WRX STI or 2022+ WRX VB. ECU tune strongly recommended after installation. Check local emissions regulations before purchasing. Professional installation recommended — header installation requires working around the turbocharger and requires proper torque on all fasteners and gaskets. Inspect for exhaust leaks after installation and after first heat cycle. Allow the header to heat cycle before final torque inspection.\u003c\/em\u003e\u003c\/p\u003e\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eBrand: GrimmSpeed\u003c\/li\u003e\n\u003cli\u003ePart Number: GRM113008\u003c\/li\u003e\n\u003cli\u003eType: Equal length exhaust header\u003c\/li\u003e\n\u003cli\u003eMaterial: Stainless steel\u003c\/li\u003e\n\u003cli\u003eConstruction: TIG-welded\u003c\/li\u003e\n\u003cli\u003eO2 Sensors: Factory bung positions retained\u003c\/li\u003e\n\u003cli\u003eWeight: 16 lbs\u003c\/li\u003e\n\u003cli\u003eApplication: 2015–2021 Subaru WRX VA — FA20DIT\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"GrimmSpeed","offers":[{"title":"Default Title","offer_id":51290165018791,"sku":"GRMGRM113008","price":1015.19,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0555\/8344\/1063\/files\/031aca3dea9125e712d3ebf6465291a1L.jpg?v=1788426008","url":"https:\/\/www.straightsiximports.com\/en-us\/products\/grimmspeed-15-21-subaru-wrx-equal-length-exhaust-header","provider":"Straight Six Imports","version":"1.0","type":"link"}