Full T304 Stainless Steel System with Electronic Valve Control
Overview
The Audi B9 S4 and S5, powered by the EA839 3.0L V6, have impressive performance potential—but the stock exhaust hides much of this engine’s true character. The Valvetronic Designs Full Valved Exhaust System unleashes its voice, delivering an aggressive, motorsport-inspired tone when desired, and stock-like refinement when needed.
Unlike typical setups requiring multiple components from different vendors, our system is engineered as a complete solution—from the OEM or aftermarket downpipe all the way to the exhaust tips. This single-package design eliminates the need for mixing and matching resonator sections or axle-backs from other brands, ensuring perfect fitment, seamless performance, and consistent sound quality.
With valves open, expect a bold exhaust note, pronounced overrun crackles, and a commanding presence. With valves closed, the car returns to quiet factory manners, with zero drone when paired with the OEM downpipe.
For those upgrading from the V8-powered B6 or B7 S4, our system delivers the level of engagement and emotional sound you’ve been missing—ensuring your B9 ownership experience is just as exciting.
Why It Works
One-Piece System Design: Eliminates the need for mixing components from multiple vendors.
Electronic Valve Control: Switch between aggressive and refined sound instantly.
Mandrel-Bent Construction: Maximizes flow for improved throttle response and power.
Sound & Control
Valves Open: Aggressive tone with rich midrange and sharp overrun crackles on deceleration.
Valves Closed: Quiet, refined, and OEM-like for comfortable daily driving.
No Drone: When paired with the OEM downpipe, cabin comfort is unaffected.
Construction & Options
Material: T304 stainless steel for long-term durability and corrosion resistance.
Weight Savings: 16.4 lb lighter than the OEM exhaust system.
Craftsmanship: Precision TIG welds and mandrel bends for optimal flow and strength.
Tips: Includes premium exhaust tips for a finished, performance-oriented look.
Fitment
2017–2024 Audi S4 (B9)
2017–2024 Audi S5 (B9)
(Doesn't fit Sportback models)
Installation Notes
Direct-fit for sedan models.
Coupe models require modification to shorten the mid-section for proper fitment. Contact info@valvetronic.com for guidance.
What’s Included
Full T304 stainless steel valved exhaust system
Electronic exhaust valves with key fob remote system
All necessary clamps and hardware
Specifications
Tubing: Full mandrel-bent T304 stainless steel
Valves: Electronic, remote-controlled
Weight Savings: 16.4 lb lighter than OEM
Finish: Brushed stainless steel
One-Piece System Design: Eliminates the need for mixing components from multiple vendors, Electronic Valve Control: Switch between aggressive and refined sound instantly, Mandrel-Bent Construction: Maximizes flow for improved throttle response and power
T304 stainless steel for long-term durability and corrosion resistance.
Full mandrel-bent 2.5" T304 stainless steel
Electronic Valve Control: Switch between aggressive and refined sound instantly.
16.4 lb lighter than the OEM exhaust system.
Paired With Single Wall Brushed Tips
One-Piece System Design: Eliminates the need for mixing components from multiple vendors, Electronic Valve Control: Switch between aggressive and refined sound instantly, Mandrel-Bent Construction: Maximizes flow for improved throttle response and power
Specifications
T304 stainless steel for long-term durability and corrosion resistance.
Full mandrel-bent 2.5" T304 stainless steel
Electronic Valve Control: Switch between aggressive and refined sound instantly.
16.4 lb lighter than the OEM exhaust system.
Paired With Single Wall Black Tips
Bolt on Installation for sedan models, Coupe models require modification to shorten the mid-section for proper fitment.
Bolt on Installation for sedan models, Coupe models require modification to shorten the mid-section for proper fitment.
Warranty Coverage
All products manufactured by Valvetronic Designs are guaranteed to be free from manufacturing defects in materials and workmanship at the time of sale. A manufacturing defect is defined as any characteristic of the product that arises during the manufacturing process which impairs its usability for the purposes for which it was designed and manufactured.
Products are guaranteed to fit and function as designed on their intended vehicle application, provided the vehicle has not been modified or incurred structural damage. Sound or tone is not a warrantable or returnable issue, as exhaust sound is subjective and not considered a defect.
Warranty Periods
304 stainless steel and titanium exhaust tubes and welds carry a Lifetime of Ownership limited warranty against defects in workmanship or material, including penetrating rust.
Mufflers and resonators carry a 3-year limited warranty against defects in workmanship or material, including penetrating rust.
Catalysts are warranted to conform to EPA emission testing and OBDII compatibility criteria for 25,000 miles from the date of installation, whichever occurs first.
Catalytic converter external shells, including end pipes, are warranted against corrosion and defective welding for 5 years or 50,000 miles from the date of installation, whichever occurs first.
Vacuum pots, electronic remotes, and mechanical valves are covered by a 1-year limited warranty.
Electronics, including 12V vacuum pumps, RF modules, and controllers, are covered by a 1-year limited warranty.
Tip finish is covered by a 1-year limited warranty.
Warranty Terms
Warranty coverage begins on the purchase date and applies only to the original purchaser.
This warranty is not transferable or assignable at any time.
Discoloration caused by heat, salt, brine, or other road treatments is not covered.
Tip finish discoloration or damage caused by heat, chemicals, lack of maintenance, road salt, brine, other road treatments, road debris, or misuse is not covered.
Valved exhaust system, Electronic exhaust valves with key fob remote system, and brushed Valvetronic tips
Valved exhaust system, Electronic exhaust valves with key fob remote system, and black Valvetronic tips
Overall rating: 4.8 / 5 from 5 reviews.
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Review highlights
Reviews
Sounds amazing.
"The exhaust sounds and looks amazing, I'm a huge fan of it, my car is tuned with extra crackles so pairing it with this exhaust brings me far too much joy, I am glad I spent the money and every time I drive my car it makes me happy. I installed this exhaust myself, I have a few warnings based on my experience. 1: If you aren't changing out the header/cats be warned that you will be in need of two bolts that are splined into the stock exhaust which are not reusable even when removed from the stock exhaust. 2: The rear hangers aren't tight enough to keep the exhaust from sitting low and near the rear bumper. 3: You may need to replace the original metal gaskets."
— David F. (5/5)
Perfect System
"Absolutely perfect system even when opened up cabin is not droney it’s a very aggressive tone exactly what I was looking for. Keeping it closed on start up might just not piss your neighbors off😂. Install not to bad I do have a coupe S5 so had to cut a little of the midsection off but wiring up was easy just the flex pipe nuts are a pain I recommend if you plan on getting a down pipe to doing it all at once might make your life a little easier."
— Matt i. (5/5)
"It is crazy good and i love it but had a tiny fitment problem."
— Muhammad (4/5)
Great Product
"Great product. Sounds amazing."
— Joshua H. (5/5)
Best exhaust for the B9 s4
"Upgrading to a Valvetronic exhaust system has significantly enhanced my driving experience. The drone that used to be present during traffic driving with my old MBRP catback exhaust is now gone, thanks to the cutting-edge technology of the Valvetronic system. With the ability to fully open and close the valves, I have more control over the sound of my exhaust. While Audi vehicles do offer some control over their valves, they don't compare to the customization offered by the Valvetronic system. With the ability to close the valves fully, I can drive with my girlfriend or family in the car without any noticeable difference in sound compared to a stock exhaust system. Additionally, installing a catless downpipe has given my car a more aggressive sound and the valves give me the ability to control it!"
— Payton (5/5)
Q&A
Does this exhaust set up require the catalytic converter to be removed?
No. It is just a cat-back.
Can I use the OEM value controller if I don’t want to use valvetronic value controller so I can use the factory drive system?
Thank you for your question! Due to variations in factory actuator designs across different build years for this model, this system is not designed to integrate directly with the factory exhaust button. To ensure consistent performance and reliability, we include our dedicated Valvetronic controller and remote, allowing you full control over the exhaust flaps regardless of your vehicle's build date.
I have a '21 A5 coupe premium plus with the s-line package. Would this exhaust work even though my car is not an S5?
This will not work as it only fits S4/5
Hi I would like to fit this to a 2016 b9 coupe and it says modifications would be needed can you please confirm what is required to to carry this out
Hi Mark! The shop installing would need to shorten the midsection
Hi It says mods are needed to fit to an s5 coupe what is needed to be done to fit it please
The mid section just needs to be shortened slightly. Message our customer service team at info@valvetronic.com if you need any more info
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