S58 catless downpipes with flanged ends

The S58 Catless Downpipe is a high-performance upgrade designed for BMW vehicles equipped with the S58 engine.

This modification offers significant improvements in exhaust flow by eliminating the restrictive catalytic converter, which allows for increased horsepower, torque, and overall engine efficiency. By reducing backpressure, the catless downpipe enhances turbo spool and throttle response, giving drivers a more exhilarating driving experience.

Why Choose an S58 Catless Downpipe?

Upgrading your S58 with catless downpipes offers a host of performance benefits. Here are some key features that make this mod a top choice for enthusiasts:

• Increase Power and Torque: By eliminating the restrictions of the stock catalytic converter, S58 downpipes maximize exhaust flow, providing substantial gains in horsepower and torque to achieve maximum power.

• Spool Faster: With less backpressure, the turbocharger is able to spool faster, delivering power more quickly, which is ideal for performance driving.

• Exotic Exhaust Sound: Enjoy a louder, more aggressive and exotic exhaust sound that enhances the driving experience. Catless downpipes unleash the raw sound of your engine without the restrictions of a catalytic converter.

• Improve Throttle-Response: Experience quicker throttle response and reduced turbo lag, ensuring your vehicle delivers power exactly when you need it.

• Enhanced Durability: Crafted from high-quality SS304 stainless steel with smooth radius bends and TIG welded construction, S58 catless downpipes like those from Mad Boy and Fat Boy Porsche are built to withstand extreme conditions, providing long-lasting performance backed by a lifetime warranty for track days or daily driving.

Whether you're looking to optimize your track performance or simply want your BMW M3, M4, or M2 to stand out with a roaring exhaust, investing in S58 catless downpipes can deliver the high-octane experience you desire.

What is a Catless Downpipe?

A catless downpipe is an aftermarket exhaust component that replaces the factory downpipe in a vehicle's exhaust system. The main feature of catless downpipes like BMW S55 downpipes, G80 M3 catless downpipes, and BMW M4 catless downpipes is that they eliminate the catalytic converter, which is a device designed to reduce harmful emissions by converting toxic gases into less harmful ones.

High-performance catless downpipes like 3.5" Fat Boy downpipes feature mandrel bent tubing in a 3" diameter to provide maximum airflow and eliminate backpressure. They connect to OEM midpipes via a 2.75" 2-bolt connection or CNC machined turbo v-band flange and may include a flex section for fitment on both RHD and LHD models. Some options like Fatboys exhaust systems even offer a 200-cell high-flow catalyst and resonators to meet emissions requirements while still maximizing performance.

How Much Horsepower Does A Catless Downpipe Add?

The amount of horsepower a catless downpipe adds depends on various factors such as the type of vehicle, engine, and other supporting modifications like tuning. Typically, S58 downpipes on a turbocharged engine like the S58 in the G80 M3, G82 M4, and G87 M2 can add anywhere between 10 to 30 horsepower on their own, primarily by reducing exhaust backpressure and improving the turbo's efficiency.

However, when paired with a performance tune, the gains can be more significant, often reaching 50+ horsepower depending on the setup. Tuning helps optimize the engine's air-fuel mixture and boost pressure to take full advantage of the freer-flowing exhaust system enabled by catless downpipes.

For naturally aspirated engines like those found in some M3 models, the gains are usually more modest, around 5 to 15 horsepower. But for serious enthusiasts, every bit of power counts, making downpipes a worthwhile investment, especially when crafted from premium materials like SS304 stainless steel with TIG welded construction and high quality grade 12 mounting hardware.