Nforcd BMW B58 4-Inch Decat Downpipe Catless Stainless Steel Performance Exhaust Upgrade for M140i/M240i/340i/440i Stage 2 Ready

BMW B58 4 Inch Cat Delete Turbo Outlet Pipe – Stainless Steel Performance Front Section for M140i, M240i, 340i, 440i

Give your B58-powered BMW the flow it deserves. This 4 inch cat delete turbo outlet pipe replaces the restrictive factory catalyst section with a free-flowing stainless steel front pipe, improving turbine efficiency, sharpening throttle response and unleashing a harder-hitting exhaust tone. Perfect for enthusiasts building a fast-road or track-focused setup and anyone planning a Stage 2 style calibration on the B58 3.0 turbo engine.

Crafted from high-grade stainless steel with smooth mandrel bends, this motorsport-focused front section reduces back pressure, helps the turbo spool sooner and supports higher power targets versus the OE converter. It is a proven hardware upgrade that pairs brilliantly with intake, intercooler and software for a properly responsive B58.

Highlights

• Large-bore 4 inch turbo outlet for maximum exhaust gas velocity
• Cat delete design for reduced restriction and improved turbocharger response
• Durable stainless construction with quality welds for long-term reliability
• Deeper, more aggressive exhaust note under load
• Ideal hardware for Stage 2 tuning strategies and higher-flow builds
• Direct fitment for B58 3.0 turbo models listed below

Compatibility

For BMW models equipped with the B58 engine, including:

• BMW M140i
• BMW M240i
• BMW 340i
• BMW 440i

Why enthusiasts choose this upgrade

We have installed this race front pipe on our own builds and many customer cars, and feedback has been excellent for fitment, finish and on-road feel. Expect quicker spool, stronger mid-range punch and a more engaging soundtrack. If you are searching for a BMW M140i exhaust upgrade, B58 cat delete, turbo front pipe, performance down pipe alternative, or a stainless steel race pipe for the M240i, 340i or 440i, this is the high-flow option that delivers.

Fitting and support

Professional installation available at MJ Modifications in Warwickshire. Request a quote: info@mjmodifications.co.uk

Important information

This is a catalyst removal pipe intended for off-road and track use only. Not suitable for road use where emissions regulations apply. ECU calibration is recommended after installation.

Search terms: BMW M140i exhaust front pipe, B58 turbo outlet, BMW 340i cat delete pipe, 4 inch BMW B58 race pipe, stainless B58 front section, M240i performance exhaust upgrade, 440i turbo down pipe alternative, B58 hardware for Stage 2, BMW 3.0 turbo exhaust mod, BMW performance parts UK.