{"product_id":"csl-s54-carbon-airbox","title":"CSL (S54) Carbon Airbox","description":"The Karbonius E46 M3 CSL (S54) Carbon Airbox is a high-performance intake system engineered to replicate and enhance the legendary BMW M3 CSL airbox. It is designed to deliver increased horsepower, sharper throttle response, and the iconic S54 induction sound. The system is constructed from 100% prepreg carbon fiber, autoclave-cured at 125°C in Spain under ISO 9001 standards, resulting in a lightweight (approx. 1.7 kg) yet exceptionally strong component.\n\nKarbonius utilized advanced 3D scans of an OEM CSL airbox to refine the design for improved airflow efficiency and cylinder filling. The airbox features carbon fiber velocity stacks with an optimized 51.5mm trumpet diameter (vs. 50mm OEM) and a redesigned sixth runner for balanced airflow distribution. Internal surfaces are hand-finished to reduce turbulence, leading to smoother airflow and better engine efficiency. All aluminum components are CNC-machined and anodized, complemented by stainless-steel hardware for longevity. The carbon weave is matched for an OEM+ appearance, and a neoprene gasket ensures a hermetic seal.\n\nWhen properly tuned and supported by other modifications, this airbox can yield up to 25 horsepower gains. It is specifically designed for the BMW E46 M3 (S54), BMW Z3 M Coupe \u0026amp; Roadster (2001–2002, S54), and BMW Z4 M (E85 \/ E86, S54).\n\nInstallation requires careful consideration. Instead of a CSL-specific dipstick, rotating the factory dipstick approximately 180 degrees is recommended for proper clearance. Several components are required and sold separately, including an IND E46 M3 CSL S54 Carbon Airbox Installation Kit, OEM BMW M3 CSL IAT Sensor, Alpha-N MAF-to-IAT Conversion Harness, OEM BMW M3 CSL Air Shut-Off Valve, OEM BMW M3 CSL Crankcase Vent Hose, and for SMG models, the OEM BMW M3 CSL SMG Reservoir \u0026amp; Bracket. Professional installation is recommended, and users should consult the emissions compliance notice.","brand":"Karbonius","offers":[{"title":"Default Title","offer_id":52662798483768,"sku":"E46AD02-CF-2","price":2349.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0970\/4895\/3144\/files\/687498631.webp?v=1784321119","url":"https:\/\/store.motormia.co\/products\/csl-s54-carbon-airbox","provider":"MOTORMIA","version":"1.0","type":"link"}