{"product_id":"exhaust-muffler-for-bmw-e30-325-1987-1991-2-5l","title":"Exhaust Muffler for BMW E30 325 (1987-1991) 2.5L","description":"\u003ch2\u003eHigh-Flow Exhaust Muffler for 1987-1991 BMW 3 Series\u003c\/h2\u003e\n  \n  \u003cp\u003e\u003cstrong\u003eWhat it does:\u003c\/strong\u003e Replaces the restrictive factory muffler and mid-pipe setup to significantly increase exhaust scavenging efficiency and lower backpressure on the M20 engine.\u003c\/p\u003e\n  \n  \u003ch3\u003eThe Stock 3 Series Restriction\u003c\/h3\u003e\n  \u003cp\u003eThe factory exhaust system on the E30 chassis was originally engineered with strict noise, vibration, and harshness (NVH) constraints, resulting in a heavily baffled muffler design and narrow pipe diameters. Over decades of thermal cycling, original mild steel components are highly susceptible to interior corrosion, exterior rust-out, and internal baffle collapse. This structural degradation creates severe exhaust bottlenecks, elevating exhaust gas temperatures (EGT) and restricting the natural volumetric efficiency of the 2.5L M20 powerplant. The resulting exhaust backpressure actively suffocates top-end horsepower, delays throttle response, and completely mutes the classic inline-six exhaust note characteristic of period-correct BMW chassis.\u003c\/p\u003e\n  \n  \u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n  \u003cp\u003eThis upgraded cat-back system utilizes enlarged 2.25-inch piping to optimize exhaust gas velocity and maximize scavenging out of the mid-pipe section. Constructed entirely from durable stainless steel, it permanently eliminates the rust vulnerabilities of the OEM mild steel setup. The assembly features CNC-machined flanges ensuring precision, leak-free fitment against the factory exhaust components, reinforced with robust TIG and MIG welding to withstand aggressive thermal expansion and structural flex during high-RPM track use. Dual 2-inch polished tips provide a period-correct aesthetic while delivering a pronounced, aggressive exhaust tone without excessive highway drone. By accelerating gas extraction, the M20 engine achieves improved mechanical breathing, sharpening throttle response and ensuring consistent power delivery across the entire rev range.\u003c\/p\u003e\n  \n  \u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n  \u003ctable width=\"100%\" style=\"border-collapse: collapse; border: 1px solid #e0e0e0; font-size: 14px;\"\u003e\n    \u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003ctd style=\"padding:8px;\"\u003e\u003cstrong\u003eFitment\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px;\"\u003e1987-1991 BMW 3 Series\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd style=\"padding:8px;\"\u003e\u003cstrong\u003eEngine \/ Chassis\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px;\"\u003eM20B25 \/ E30\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003ctd style=\"padding:8px;\"\u003e\u003cstrong\u003eStock Output\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px;\"\u003e168 hp \/ 164 lb-ft (Approx)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd style=\"padding:8px;\"\u003e\u003cstrong\u003ePart Number\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding:8px;\"\u003eN\/A\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/table\u003e\n \n  \u003ch3\u003eCompatibility\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003e1987 BMW 325i \/ 325is \/ 325ix\u003c\/li\u003e\n    \u003cli\u003e1988 BMW 325i \/ 325is \/ 325ix\u003c\/li\u003e\n    \u003cli\u003e1989 BMW 325i \/ 325is \/ 325ix\u003c\/li\u003e\n    \u003cli\u003e1990 BMW 325i \/ 325is \/ 325ix\u003c\/li\u003e\n    \u003cli\u003e1991 BMW 325i \/ 325is \/ 325ix\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch3\u003eThe BMW Precision\u003c\/h3\u003e\n  \u003cp\u003eDesigned for the demanding European tuner, this exhaust hardware restores inline-six performance with exact tolerances, ensuring optimized power delivery and a refined, resonance-free exhaust note without triggering mechanical faults or fitment issues.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":50172232794360,"sku":"DS-EZAB49R45","price":359.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/exhaust-muffler-for-bmw-e30-325-1987-1991-2-5l-1.webp?v=1786906729","url":"https:\/\/performancechiptuning.com\/fr\/products\/exhaust-muffler-for-bmw-e30-325-1987-1991-2-5l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}