APR Cat Back Exhaust System – Audi S3 Saloon
The APR Catback Exhaust System personalizes your vehicle’s looks, sound and performance. Beautifully hand-crafted T304-stainless-steel components adorn the system with stunning TIG-welding throughout. Our straight-through brushed-finished mufflers smooth the exhaust note to a deep growl, without adding restrictions, while our Helmholtz resonator reduces unwanted frequencies. Strong high-quality bracketry and OEM-style clamps hold the system steadily in place, making the install or removal a snap, and fitment simple, yet precise. A cast 3” to quad 2.5” rear splitter creates an ultra-smooth transition, steadily feeding exhaust gasses out of the system, while looking tidy from under the rear bumper. Our cast valve housings enable the vehicle to be fitted with the factory electronic valve actuators, retaining OEM valve operation. Finally, removable 4″ polished slash-cut exhaust tips finish the system, adding a classy motorsport-inspired touch to the rear of the vehicle.
- T304 stainless-steel construction
- Argon-back-purged TIG welding throughout
- Single 3″ to quad 2.5″ mandrel-bent brushed tubing
- Ultra-smooth cast 3″ to quad 2.5″ splitter
- Brushed-finished straight-through sound-absorption mufflers and Helmholtz frequency reducing resonator
- Polished 4″ slash-cut exhaust tips (removable)
- Cast valve housings and brackets for OEM electronic actuators
- Rugged and precise mounting brackets
- OEM style slip clamps and Torca AccuSeal T304 tip clamps
- Direct fit to the OEM and APR Race DP exhaust systems with the included link and reducer pipes
- Low-profile design, suitable for lowered vehicles
- Larger diameter piping compared to stock
- Larger diameter tips compared to stock
- No increase in weight compared to stock
- Designed, developed, assembled and quality controlled in-house
- Easy to install
- Limited lifetime warranty
Our exhaust system uses larger piping compared to the factory exhaust system, yet weighs the same. We use 3″ OD piping, which then splits to a quad 2.5″ design. The factory system uses 2.57″ piping before the resonator and 2.78” thereafter. Finally, our system’s 4″ exhaust tips dwarf the factory oval tips, giving the rear of the vehicle a sportier look.
Mufflers and Resonators
The rear mufflers are responsible for reducing the exhaust note and do so without adding unnecessary restrictions to the system. Each unit features two straight-through perforated tubes that are tightly wrapped with stainless steel and fiberglass material. With the valves closed, the system is tamer, but once opened, the system sounds deep, throaty and aggressive! The mufflers have a beautiful brushed finish, and are tucked high in the exhaust tunnel, making them perfect for lowered vehicles and a treat to see when looking at the vehicle from the rear.
The front resonator is responsible for eliminating unwanted sound frequencies from the cabin. This is done without introducing added restrictions to the system. Using Helmholtz technology, sound waves bounce through the chamber and back into the exhaust stream, eliminating the undesirable frequencies to make the exhaust note more pleasing. During cruise, with the valves closed, the system remains calm.
We cast the axle-back splitter to maximize the system’s performance by keeping exhaust velocity high and back pressure low. This is accomplished by gradually splitting the system from a single 3” pipe to quad 2.5” pipes. The organically shaped casting allows us to make this transition gradually as to not disturb the flow of gasses. Furthermore, as this component is visible from the rear of the vehicle, we made sure form matched function with a beautiful surface finish, TIG welding, unique bracketry and brushed, mandrel bent tubing.
Our system features two valves that allow control of the volume of the system via the factory exhaust valve actuators. In doing so, the system can go from tame to aggressive instantly! Unlike pneumatic systems, and other common valves found in the market today, our system maintains identical OEM operation all the way down to the factory valve actuation angles. Furthermore, the system is fully compatible with exhaust remotes, allowing end users to manually open the system at the click of a button.
We cast the valve housings out of T304 stainless-steel. Internally the system uses CNC-machined T303 components and brass bushings, which have stood up to our extreme torture testing. All necessary hardware is welded into place and is designed to combat heat and vibration for years to come.
Our brackets ensure a strong and precise fit, every time. With our design, you’ll never need to worry about the brackets sagging and losing their shape over time, or the post slipping out of the hangers. The brackets are rigid, exact in their position, fit snugly in place and are made to stand the test of time.
We use T304 stainless steel tubing throughout. We brush and de-burr all pipes, use mandrel bending techniques to ensure the pipes keep a constant diameter throughout, and use argon-back purged TIG welding for a strong and attractive weld.
Our polished slash-cut 4” exhaust tips upgrade the rear of the vehicle dramatically. The motorsport-inspired tips tuck nicely into the factory valance, gently following the valance’s curves and demanding all the right attention in all the right places. We laser etch a small and discreet APR logo onto the top of each tip, and we use T304 stainless Torca AccuSeal clamps that bolt on with ease with hardware that rotates out of sight. Lastly, since the tips are removable, you can upgrade to any one of our optional tip designs at any time.
Our system uses OEM-style low-profile slip clamps and T304 stainless-steel Torca AccuSeal clamps for the exhaust tips. Our clamp selection allows the system to sit high in the exhaust tunnel, as is favored by lowered vehicles, with ultimate compatibility no matter what DP you may have. The clamps make for easy swapping of the exhaust tips, and slide out of the way to make adding or removing a Race DP easy. Each connection point is strategically placed to ensure the system has minimal opportunity to rotate during install or during years of heavy driving. Finally, because there are no flanges or swedges on the pipe, fitting the system to the factory DP, APR Race DP, or other Race DP is a breeze. There’s no cutting, welding, or glaring compatibility issues, and there are no gaskets to replace.
We’ve designed our system to be 100% bolt-on with the factory exhaust DP and APR Race DP. There’s no cutting, welding, or finagling to get the system to fit. It simply bolts on thanks to the included reducer for use with the factory DP, and link pipe for use with the APR Race DP.