Milltek 80mm Large Bore Downpipe & Hi-Flow Sports Cat - Audi RS6 C8 - SSXAU909
Ships free in the US
Make sure this fits your car
Fits: RS6 / RS7 C8
- Shop tested in Dallas
- Free pickup in Dallas
- Installs at our shop
The Milltek 80mm Cat Back Large Bore Downpipe & Hi-Flow Sports Cat is a turbo-back component engineered for the Audi RS6 C8 (4.0L bi-turbo V8), Audi RS7 C8, and Audi S8 D5 (4.0L TFSI V8). This system optimizes exhaust flow downstream of the turbos and ahead of the cat-back system, unlocking measurable power gains and refined acoustic character.
Manufactured from T304L stainless steel with mandrel-bent piping (3.15" / 80mm bore) and a high-flow sports catalytic converter (200 CPSI), the downpipe delivers direct factory fitment using OEM mounting points. The hi-flow cat maintains emissions compliance while reducing back pressure. Stage 2 ECU software is required to unlock full performance potential.
Fitment
- Audi RS6 C8 4.0L bi-turbo V8 (Performance Edition, 2020+)
- Audi RS7 C8 4.0L bi-turbo V8 (2019+)
- Audi S8 D5 4.0L TFSI V8 Standard Wheelbase (2020+)
- Audi S8 D5 4.0L TFSI V8 Long Wheelbase (2020+)
Requires integration with OE or Milltek cat-back exhaust system. No OEM modifications necessary.
Designed and manufactured in the UK with 40+ years of performance exhaust heritage. Tested at the Nurburgring.
Specifications
- Pipe diameter: 80mm (3.15")
- Fitting time: 4.5 to 5 hours, including removing the factory system
- Off-road / competition use only. Not legal for use on public roads in the US.
Fitment
- Audi > RS6 > C8 4.0 V8 bi-turbo in Performance Edition > 2020 and Later
- Audi > RS7 > C8 4.0 V8 bi-turbo > 2019 and Later
- Audi > S8 > D5 4.0 TFSI V8 Saloon/Sedan - Long Wheel Base (GPF US/ROW Models) > 2020 and Later
- Audi > S8 > D5 4.0 TFSI V8 Saloon/Sedan - Standard Wheel Base (GPF US/ROW Models) > 2020 and Later
Listed for these cars. Check the title and description for exact years, body styles and drivetrain.
| Make | Model | Chassis | Years | Fits |
|---|---|---|---|---|
| Audi | RS6 / RS7 | C8 | 2020+ |
Not sure? Call or text 945-954-1142 with your car or VIN.
- Free US shipping on orders over $250.
- Free pickup at our Dallas shop, usually ready within 24 hours.
- Unused parts can be returned within 30 days. Tunes, opened electronics, merch and installed parts are final sale.
- Want it installed? Book the install at thegbmotors.com.
Full details are on our shipping and returns page.
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