Audi S4 Downpipes – Catted & Decat Performance Exhaust Upgrades

Audi S4 Downpipes – Unleash the Full Potential of Your Engine

The Audi S4 is an icon among sport sedans, combining luxury and performance across multiple generations. Whether you own a B8/B8.5 3.0 TFSI supercharged V6, a B9 3.0 TFSI turbocharged V6, or an earlier V8-powered S4, one common limitation is the restrictive OEM downpipe. Upgrading to a performance Audi S4 downpipe is one of the most effective modifications to increase horsepower, reduce turbo lag, and enhance exhaust sound.

Why Upgrade to a Performance Audi S4 Downpipe?

The stock downpipe is designed for emissions compliance and noise reduction, but it limits exhaust flow and overall performance. Installing a high-flow Audi S4 downpipe provides several benefits:

• Increased horsepower and torque – improved exhaust flow reduces backpressure and boosts engine efficiency.
• Faster turbo spool and throttle response – essential for responsive acceleration.
• Enhanced exhaust tone – catted downpipes offer a refined, sporty sound, while decat downpipes deliver an aggressive, motorsport-inspired roar.
• Lower exhaust gas temperatures – better thermal efficiency protects key components under high load.
• Perfect for ECU tuning – a must-have upgrade for Stage 1, Stage 2, and hybrid turbo builds.

Types of Audi S4 Downpipes

We offer a wide range of Audi S4 downpipes designed for different tuning goals and driving styles:

Catted Audi S4 Downpipes

Catted downpipes feature a high-flow sports catalytic converter, providing an excellent balance between emissions compliance and performance gains. Perfect for street-driven cars in regions with strict emissions testing.

Decat Audi S4 Downpipes

Decat downpipes eliminate the catalytic converter entirely, delivering maximum exhaust flow and peak performance. Ideal for track-focused builds or areas without emissions restrictions.

Material Options: Stainless Steel & Titanium

The material you choose affects performance, weight, and durability:

• Stainless steel downpipes – corrosion-resistant, durable, and cost-effective; suitable for most street and track builds.
• Titanium downpipes – ultra-lightweight, motorsport-grade, and optimized for maximum thermal efficiency.

Engine & Model Compatibility

Our Audi S4 downpipes are designed for seamless fitment across multiple generations and engine configurations:

• Audi S4 B8 / B8.5 3.0 TFSI Downpipes – optimized for supercharged V6 engines, perfect for Stage 1 and Stage 2 setups.
• Audi S4 B9 3.0 TFSI Downpipes – engineered for the turbocharged V6, supporting hybrid turbos and advanced tuning.
• Audi S4 B6 / B7 4.2 V8 Downpipes – high-flow solutions for naturally aspirated V8 builds.

Performance Gains with Audi S4 Downpipes

Installing a performance Audi S4 downpipe provides measurable performance improvements:

• +20–30 HP with a downpipe alone.
• +40–75 HP when paired with Stage 2 ECU tuning.
• Increased mid-range torque for stronger pull and better drivability.
• Sharper throttle response and reduced turbo lag.

Choosing the Right Diameter

Choosing the optimal pipe diameter is essential for maximizing gains:

• 2.5-inch downpipes – ideal for Stage 1 tuning and mildly modified setups.
• 3-inch downpipes – recommended for Stage 2 upgrades, hybrid turbos, and high-output builds.

All our Audi S4 downpipes are designed for direct bolt-on installation, requiring no cutting or welding.

Build Quality & Engineering

Our performance Audi S4 downpipes are manufactured to the highest standards to ensure reliability and performance:

• Mandrel-bent tubing for smooth, unrestricted exhaust flow.
• High-grade stainless steel or titanium construction.
• Precision TIG welding for maximum strength and durability.
• OEM-style flanges and fittings for a perfect fit.

Tuning Potential

Pairing your Audi S4 downpipe with ECU tuning unlocks the engine’s full potential:

• Substantial horsepower and torque improvements.
• Optimized boost control and fueling strategies.
• Sharper throttle response and smoother power delivery.
• Custom exhaust sound based on catted or decat configuration.

Daily Driving vs Track Builds

For daily-driven cars, catted downpipes provide excellent performance while maintaining street compliance. For track-oriented builds, decat downpipes deliver maximum flow, aggressive sound, and top-end power.

Conclusion

Upgrading to a performance Audi S4 downpipe is one of the most effective ways to unlock more power, improve turbo efficiency, and enhance exhaust sound. Whether you choose a catted downpipe for everyday usability or a decat downpipe for ultimate motorsport performance, our selection of Audi S4 downpipes ensures exceptional quality, precise fitment, and proven results. Transform your S4 today.