BMW M340i

Unleash the Power: The Benefits of a Catless Downpipe for Gen 1 and Gen 2 B58 Engines

When it comes to boosting the performance of your Gen 1 or Gen 2 B58 engine, one modification that enthusiasts often turn to is installing a catless downpipe. This small yet significant upgrade can have a profound impact on your vehicle's power, sound, and overall driving experience. In this blog post, we'll explore the benefits of a catless downpipe for Gen 1 and Gen 2 B58 engines, shedding light on why this modification is popular among BMW enthusiasts. 

The Gen 1 B58 engine can be found in:

  • BMW 340i
  • BMW 540i
  • BMW X3
  • BMW X5
  • BMW X7

The Gen 2 B58 engine can be found in:

  • BMW M340i
  • BMW M240i
  • BMW M440i
  • Toyota MK5 Supra
  1. Increased Horsepower and Torque

One of the most significant advantages of installing a catless downpipe on your B58 engine is the substantial increase in horsepower and torque. The stock catalytic converter-equipped downpipes are restrictive, limiting the flow of exhaust gases and thereby reducing power. By replacing these with a catless downpipe, you eliminate these restrictions, allowing for a smoother and more efficient exhaust gas flow. This, in turn, leads to a noticeable increase in horsepower and torque.

  1. Improved Exhaust Flow

Catless downpipes enhance the exhaust flow by eliminating the catalytic converters and reducing exhaust backpressure. The improved flow results in better turbo spooling and a more linear power delivery. Your Gen 1 or Gen 2 B58 engine will feel more responsive and lively, especially in the mid and high RPM ranges.

  1. Enhanced Engine Sound

One of the most enjoyable benefits of a catless downpipe is the change in exhaust note. The absence of catalytic converters and the improved flow lead to a deeper and more aggressive exhaust tone. Your B58 engine will produce a captivating growl that will turn heads and bring a smile to your face every time you step on the throttle. It's an auditory experience that complements the increased performance perfectly.

  1. Reduced Turbo Lag

Turbocharged engines, like those found in Gen 1 and Gen 2 B58 platforms, can suffer from turbo lag. A catless downpipe helps reduce this lag by allowing the turbos to spool up more quickly, resulting in improved throttle response. This means you'll experience a more immediate and consistent surge of power when you press the gas pedal.

  1. Potential Fuel Efficiency Improvements

While the primary focus of a catless downpipe is on performance, some users have reported slight improvements in fuel efficiency. The enhanced exhaust flow can lead to more complete combustion, which might result in slightly better mileage under certain driving conditions.

  1. Customization and Personalization

Catless downpipes are often available in various sizes and materials, allowing you to customize the upgrade to your specific preferences and needs. Whether you prefer stainless steel or lightweight materials like titanium, or if you want to fine-tune the diameter for optimized performance, there's a catless downpipe option for you.


For Gen 1 and Gen 2 B58 engine owners looking to unlock the true potential of their vehicles, a catless downpipe is a modification worth considering. The increase in horsepower and torque, improved exhaust flow, enhanced engine sound, reduced turbo lag, and potential fuel efficiency improvements make it a compelling option for enthusiasts who want to take their BMW driving experience to the next level.

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