6 Inch B58 Downpipe for Supra 3.0T & BMW M240i, M340i, 340i, 440i, M440i, 540i, 640i, 740i, 840i, X5, Z4 Select one:Catless oiled cotton media engineered to

oiled cotton media engineered to have the most improved airflow possible and still capture contaminants while increasing horsepower

to determine which JB4 harness your vehicle requires

ensuring long-lasting performance under any condition

Go from sounding 100% stock to an exotic exhaust system for a fraction of the cost with just one click of a button

Pump Weight: 2

6 Inch B58 Downpipe for Supra 3.0T & BMW M240i, M340i, 340i, 440i, M440i, 540i, 640i, 740i, 840i, X5, Z4 Select one:Catless oiled cotton media engineered toThe ARM 6" B58 Downpipe is one of the foundational upgrades for giving your B58 powered BMW more power, torque, and sound. The stock B58 downpipe comes from the factory with a catalyst that severely restricts exhaust flow, causing excessive backpressure with increased boost. Upgrading to the ARM 6" B58 Downpipe unlocks power, improves turbo spool, allows you to safely run stage 2+ tuning, all while improving the sound of your B58 powered BMW. The ARM