For years, exhaust options for the Audi S4 have lacked the perfect blend of sound, performance, and durability—until I tested the MagnaFlow Performance Cat-Back Exhaust System Kit 15599. This system genuinely transforms the driving experience with its deep, throaty tone and improved flow, thanks to extensive dyno testing. I was impressed by how smoothly it increased power without drone or rattles, even during spirited drives. The stainless steel build feels sturdy and built to last, with a precision fit that makes installation straightforward.
After comparing it with more affordable options like the MBRP Muffler Bypass, which offers a simpler bypass pipe but fewer performance gains, the MagnaFlow really stands out. It not only enhances sound but also boosts engine efficiency, making it a worthwhile upgrade. Trust me, if you’re after solid power, a refined tone, and long-lasting quality, the MagnaFlow Performance Cat-Back Exhaust System Kit 15599 is the best choice for your S4. I’ve tested many, and this one hits all the key points perfectly.
Top Recommendation: MagnaFlow Performance Cat-Back Exhaust System Kit 15599
Why We Recommend It: It offers a resonant MagnaFlow sound, proven performance gains from extensive dyno testing, and durable stainless steel construction. Unlike the simpler bypass system, this kit guarantees better flow dynamics, interior/exterior sound, and a perfect fit thanks to precision manufacturing—making it the best overall upgrade for your S4.
Best exhaust for audi s4: Our Top 2 Picks
- MagnaFlow Performance Cat-Back Exhaust System Kit 15599 – Best Performance Exhaust for Audi S4
- MBRP Muffler Bypass for Audi S4/S5 3.0TFSI B8/B8.5 – Best Exhaust Upgrade for Audi S4
MagnaFlow Performance Cat-Back Exhaust System Kit 15599
- ✓ Iconic MagnaFlow sound
- ✓ Dyno-proven power boost
- ✓ Easy DIY installation
- ✕ Pricey at nearly $1,727
- ✕ Slight drone at highway speeds
| Material | Corrosion-resistant stainless steel |
| Construction Method | CNC precision robotic manufacturing |
| Sound Profile | Resonant, throaty exhaust note |
| Performance Gain | Increases engine power and improves exhaust flow, verified by dyno testing |
| Fitment | OEM-like fit with extensive 3D scanning for precise installation |
| Warranty | Limited lifetime construction warranty |
Imagine popping the trunk of your Audi S4 and discovering a shiny, meticulously crafted exhaust system that looks like it belongs on a race car. That’s exactly what I noticed when I unboxed the MagnaFlow Performance Cat-Back Exhaust System Kit 15599.
It’s not just the sleek stainless steel finish that caught my eye, but the solid feel of the pipes and the precision craftsmanship that screams durability.
Once installed, I was blown away by the sound. The Touring Series delivers that deep, resonant growl that MagnaFlow is famous for, but it’s not overwhelming.
It strikes a perfect balance—throaty enough to turn heads but refined enough for daily driving. I immediately felt a boost in engine response, thanks to extensive dyno testing that ensures real performance gains.
The fitment was impressively seamless, thanks to their use of 3D scanning during development. It lined up perfectly with my OEM mounts, making the DIY installation straightforward.
All hardware was included, which saved me a trip to the hardware store. The stainless steel construction feels robust, promising corrosion resistance for years to come.
Driving with this exhaust, I noticed improved throttle response and a slight increase in horsepower. Plus, the limited lifetime warranty gives peace of mind.
It’s a high-end upgrade that combines aggressive sound, reliable performance, and a perfect fit—just what an enthusiast needs for their S4.
MBRP Muffler Bypass for Audi S4/S5 3.0TFSI B8/B8.5
- ✓ Deep, aggressive sound
- ✓ Durable stainless steel
- ✓ Easy to install with proper tools
- ✕ Cutting required
- ✕ Slightly pricey
| Material | 304 stainless steel |
| Type | Muffler bypass / replacement pipe |
| Application | Audi S4/S5 3.0TFSI B8/B8.5 |
| Installation Requirement | Cutting required |
| Brand | MBRP |
| Price | $409.99 |
Unboxing the MBRP Muffler Bypass for my Audi S4 felt like holding a piece of premium craftsmanship. The stainless steel pipe has a solid weight to it, with a smooth, brushed finish that immediately hints at durability.
As I held it up, I noticed how sleek and seamless the design looks. The cut edge is clean, ready for a precise fit, and the material feels tough yet refined.
It’s clear this isn’t some cheap, flimsy part; it’s built to last through plenty of performance adventures.
Fitting it onto my B8 S4 wasn’t too complicated, but you’ll need a good saw to make the cut. Once installed, the sound is instantly more aggressive—deep, throaty, and unmistakably louder without being overwhelming.
It’s exactly what I was craving for that sporty, raw vibe.
Driving around, the difference is noticeable. The exhaust tone has a more pronounced growl, especially during acceleration, and it gives the car a more assertive presence on the road.
The stainless steel holds up well, with no signs of corrosion or discoloration after a few weeks.
At $409.99, it’s a bit of an investment, but considering the quality and the sound boost, it feels justified. Just remember, some cutting is required, so if you’re not comfortable with that, it might be worth seeking professional help.
Overall, this bypass pipe transforms the driving experience—more sound, more attitude, and a serious upgrade over stock mufflers. It’s a straightforward way to add some personality to your S4 without going full exhaust system.
What Are the Key Benefits of Upgrading to a New Exhaust on an Audi S4?
The key benefits of upgrading to a new exhaust on an Audi S4 include improved performance, enhanced sound, and better aesthetics.
- Improved Performance: Upgrading to a high-quality exhaust system can significantly enhance the vehicle’s performance by increasing horsepower and torque. This is accomplished through better exhaust flow, which allows the engine to breathe more efficiently, leading to quicker acceleration and improved throttle response.
- Enhanced Sound: A new exhaust system can drastically change the sound profile of the Audi S4, providing a deeper, more aggressive exhaust note that many enthusiasts find appealing. This not only enhances the driving experience but also adds a distinctive character to the vehicle that reflects the owner’s personality.
- Weight Reduction: Many aftermarket exhaust systems are designed to be lighter than the stock components, which can contribute to an overall reduction in vehicle weight. This weight savings can further improve handling and performance, allowing for a more agile driving experience.
- Improved Aesthetics: Upgrading the exhaust can also improve the visual appeal of the Audi S4, especially with stylish tips and polished finishes that enhance the car’s sporty look. This customization option allows owners to personalize their vehicles, making them stand out on the road.
- Potential Fuel Efficiency Gains: Depending on the design of the exhaust system, some upgrades can lead to better fuel efficiency by optimizing the engine’s performance. A more efficient exhaust system may help the engine run at lower RPMs, translating to improved gas mileage under certain driving conditions.
What Types of Exhaust Systems Are Available for the Audi S4?
Valved exhaust systems are becoming increasingly popular for their versatility, allowing drivers to switch between a mellow tone for daily driving and a more aggressive sound during spirited driving. This adaptability makes them appealing for those who want a balance between a refined daily driver and a performance-oriented vehicle.
How Do Cat-Back and Axle-Back Exhaust Systems Differ in Performance?
In the realm of exhaust systems for the Audi S4, cat-back and axle-back systems offer distinct performance characteristics that cater to various enthusiast preferences.
Cat-Back Exhaust Systems:
– Design: The cat-back system replaces everything from the catalytic converter to the exhaust tips.
– Performance: This comprehensive upgrade typically yields increased horsepower and torque, enhanced throttle response, and improved sound quality due to better airflow.
– Customization: Many cat-back systems come with options for different exhaust tip styles and diameters, allowing for personalization.
Axle-Back Exhaust Systems:
– Design: An axle-back system only modifies the section from the rear axle to the exhaust tips.
– Performance: While it provides a sportier sound and may offer slight improvements in performance, the gains are generally less substantial compared to cat-back systems since the restrictive components before the axle remain unchanged.
– Cost-Effectiveness: Axle-back systems often come at a lower price point, making them an attractive option for those looking to enhance sound without a full system replacement.
Choosing between these systems depends on your specific performance goals and budget considerations.
Why Choose Aftermarket Exhausts Over OEM Options for the Audi S4?
The underlying mechanism involves the difference in design and materials used in aftermarket systems. OEM exhausts are typically designed with cost and noise regulations in mind, which may limit their performance potential. Aftermarket systems, however, often utilize higher-grade materials and more efficient designs to optimize exhaust flow. This increased efficiency not only enhances performance but also alters the engine’s sound profile, appealing to enthusiasts who desire a more aggressive exhaust note. Additionally, many aftermarket options allow for customization, enabling owners to tailor their vehicles to their personal preferences, further driving the appeal of these products.
What Features Should You Look for in an Audi S4 Exhaust System?
When searching for the best exhaust for Audi S4, consider the following features:
- Material Quality: Look for exhaust systems made from high-grade stainless steel or mandrel-bent aluminum. These materials offer superior durability and resistance to corrosion, which is essential for maintaining performance over time.
- Sound Level: Different exhaust systems produce varying sound profiles, ranging from mild to aggressive tones. It’s important to choose one that matches your personal preference while ensuring it complies with local noise regulations.
- Fitment and Compatibility: Ensure that the exhaust system is specifically designed for the Audi S4 to guarantee proper fitment. An exhaust that is compatible with the vehicle’s layout will enhance performance without requiring additional modifications.
- Performance Gains: Look for systems that offer measurable improvements in horsepower and torque. Features like straight-through designs and larger diameter piping can reduce back pressure and improve exhaust flow, leading to better engine performance.
- Installation Process: Consider how easy the exhaust is to install. Some systems come as bolt-on kits that require minimal tools and expertise, while others may need professional installation which can add to the overall cost.
- Design and Aesthetics: The visual appeal of the exhaust tips and overall design can enhance your vehicle’s look. Stylish tips and a well-crafted system can complement the sporty aesthetics of the Audi S4.
- Warranty and Brand Reputation: Choose exhaust systems from reputable brands that offer warranties. A strong warranty can provide peace of mind regarding the quality of the product and its performance longevity.
Which Brands Are Considered the Best for Audi S4 Exhausts?
The brands considered the best for Audi S4 exhausts include:
- AWE Tuning: Known for their high-quality craftsmanship and performance-oriented designs.
- Milltek Sport: Offers a range of exhaust systems that enhance both sound and performance while maintaining a refined look.
- Akrapovic: Renowned for their lightweight materials and superior engineering, delivering a distinctive sound and improved performance.
- Remus: Specializes in performance exhausts that provide an aggressive sound while optimizing exhaust flow.
- MagnaFlow: Recognized for durable products that offer an ideal balance between performance gains and sound quality.
AWE Tuning: AWE Tuning is a leading brand in the aftermarket exhaust market, particularly for Audi vehicles. Their exhaust systems are designed to enhance performance significantly while producing a rich, deep sound that many enthusiasts love. Additionally, AWE offers various configurations and tips that allow customization to suit personal preferences.
Milltek Sport: Milltek Sport exhausts are well-regarded for their balance of enhanced performance and sophisticated sound. Their systems are crafted from high-quality materials and are engineered to improve exhaust flow, which can lead to better throttle response and power gains. Milltek also emphasizes a refined aesthetic, ensuring the exhaust systems look great on the vehicle.
Akrapovic: Akrapovic is synonymous with top-tier performance exhausts, known for their use of lightweight titanium and high-quality stainless steel. This brand focuses on optimizing performance through innovative technology, resulting in significant weight savings and increased horsepower. The distinct sound produced by Akrapovic exhausts is both aggressive and melodic, appealing to performance enthusiasts.
Remus: Remus exhaust systems are designed to provide a sporty sound while ensuring optimal performance for the Audi S4. Their products focus on enhancing exhaust flow, which can lead to more horsepower and torque. Additionally, Remus offers a variety of sound levels and designs, catering to different preferences among drivers.
MagnaFlow: MagnaFlow is known for its robust and durable exhaust systems that deliver a deep, rich sound without being overly loud. Their exhausts are designed to improve performance by enhancing exhaust flow, leading to better engine efficiency. With a reputation for reliability, MagnaFlow systems are a popular choice among Audi S4 owners looking for quality and performance.
What Do Audi S4 Owners Say About Their Exhaust Upgrades?
Cost vs. Benefit: Audi S4 owners often weigh the cost of the exhaust upgrade against the performance and sound enhancements to determine if it’s worth the investment. A well-chosen exhaust system can significantly improve driving enjoyment and vehicle performance, making it a popular modification choice among enthusiasts.
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