MAD BMW Toyota B58 Fat Boy 5" Catless Downpipe M240 340 440 Supra Race Competition Use Only



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Meet the MAD B58 Fat Boy 5'' catless downpipe.

The MAD 5 inch Catless B58 Downpipe is a high-performance aftermarket upgrade for BMW B58 engine vehicles, designed to increase power and torque while improving exhaust flow. This downpipe is made from premium quality stainless steel and is precision-engineered to fit perfectly with the stock exhaust system, ensuring a seamless installation process.

With a 5 inch diameter, this downpipe provides unrestricted exhaust flow, which reduces backpressure and increases horsepower and torque output. It also features a catless design, which eliminates the factory catalytic converter for even more performance gains. This makes it an ideal choice for car enthusiasts who are looking to improve the performance and sound of their BMW B58 engine vehicles.

The MAD 5 inch Catless B58 Downpipe is designed to withstand the high temperatures and pressures of high-performance driving, ensuring reliable performance for years to come. 

Installation of the MAD 5 inch Catless B58 Downpipe is straightforward and can be completed with basic hand tools.

Overall, if you're looking to improve the performance and sound of your BMW B58 engine vehicle, the MAD 5 inch Catless B58 Downpipe is a must-have upgrade. It delivers significant performance gains while also adding a much needed sound improvment.

Expect up to a 30HP increase on a tuned BMW / Toyota Supra B58 with stock turbo, even more on cars with upgraded turbo.



  • Compatible with right-hand drive and left-hand drive vehicles
  • Smooth bends for maximum airflow without any drone
  • Up to 30HP increase on the stock turbos, even more on upgraded turbos
  • Lifetime warranty on defects and fitment
  • Spot on fitment
  • Flex section



  • 2015+ BMW M240i & Xdrive
  • 2016-2019 BMW 340i & Xdrive
  • 2016+ BMW 440i & Xdrive
  • 2016+ BMW 540i & Xdrive
  • 2016+ BMW 740i & Xdrive
  • 2017-2020 X3 M40
  • 2017-2020 X4 M40
  • 2019+ Toyota Supra 3.0L

Race Competition Use Only