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MAD

MAD Fat Boy 5.0" Catted Downpipe B58 2025+ Gen 3 M340 M440

MAD Fat Boy 5.0" Catted Downpipe B58 2025+ Gen 3 M340 M440

Regular price $369.00 USD
Regular price $369.00 USD Sale price $369.00 USD
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SKU:MAD-128

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  • Free shipping in the continental US
  • Fitment help from our shop
  • 30-day returns on most unused parts

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Product Details

About this part

Enhance your 2025+ BMW M340 & M440 with the MAD BMW B58 Gen 3 5" 200 Cell Catted Downpipe—engineered specifically for performance enthusiasts seeking a cleaner and refined upgrade. Built with premium-quality 304 stainless steel and equipped with a high-flow catalytic converter, this downpipe delivers impressive power gains, increased airflow, and quicker turbo response without the typical fuel smell of a catless design.

Enjoy a deeper, richer, and more aggressive exhaust note compared to your stock setup, but with a refined tone that's smoother and cleaner than catless options. The MAD catted downpipe strikes the ideal balance between noticeable performance gains and everyday drivability, ensuring reliability and comfort for street and track use alike.

Precision welds, exceptional craftsmanship, and direct bolt-on installation make this downpipe an essential upgrade for your BMW, providing maximum benefits without compromising convenience.

Features:

  • High-quality 304 stainless steel construction for durability
  • 5-inch diameter offers significant airflow improvement over stock
  • High-flow catalytic converter eliminates fuel smell common with catless downpipes
  • Deeper, aggressive, yet refined exhaust note
  • Noticeable horsepower and torque increases
  • Perfect bolt-on fitment for hassle-free installation
  • Ideal for enthusiasts who want power and sound without compromise

Fitment:

  • 2025+ BMW M340
  • 2025+ BMW M440
Fitment

Not sure it fits? Contact us with your car's year, model and VIN and we'll help you confirm before you order.

If a part doesn't fit as expected, contact us and we'll work with you to resolve it.

Majority of products have a fitment section in the product description or within the title.

Returns
  • Unused, uninstalled parts can be returned or exchanged within 30 days of the order date.
  • To start a return: Contact us first, don't use Return to Sender.
  • Returns can have up to a 20% restocking fee.
  • Built-to-order and special-order items can't be returned or cancelled once production begins.

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Shipping
  • Orders are processed 7 days a week to ensure your product ships as quickly as possible.
  • Inspect parts within 10 days of delivery, and reach out regarding any damage or missing pieces.

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Warranty
  • All parts retain the manufacturer's warranty.
  • Warranty claims are subject to the manufacturer's approval.

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