Milltek Downpipes & Sports Cats for Audi RS6 C8 4.0 V8 bi-turbo in Performance Edition (Non OPF/GPF Models - USA/ROW Models) (2020 onwards) – Improved Flow, Sports Catalyst
This is Milltek's large-bore downpipe with hi-flow sports cat for the Audi S8 D5 4.0 TFSI V8 Saloon/Sedan - Standard Wheel Base (Non OPF/GPF US/ROW Models). It replaces the restrictive factory downpipe with a larger-bore pipe fitted with a high-flow sports catalyst in place of the standard unit, using a less dense substrate that flows significantly better than the factory cat while still treating the exhaust gases passing through it. It's offered in versions to suit the factory or a Milltek system, so you can pick the setup that suits how the car's used.
It sits between a stock downpipe and a full de-cat: a genuine flow gain suited to a Stage 1 or Stage 2 remap, without giving up the catalyst entirely the way a de-cat pipe does.
In the UK, a replacement catalyst on a car first registered from 1 March 2001 needs ECE R103 type-approval to be road legal, so check the EC Approved line in the specification for the version you choose.
Specifications
-
System Type: Large Bore Downpipes and Hi-Flow Sports Cats
-
Pipe Diameter: 80mm (3.15")
-
EC Approved: No
-
Race System: Yes
-
Fitting Time: approx. 3.5 to 4.5 hours (Milltek figure)
Key Features
- Made from T304L aircraft-grade stainless steel, which is anti-magnetic and resists discolouration
- Mandrel-bent pipework keeps a constant diameter through every bend for unrestricted flow
- 80mm (3.15") pipework
- High-flow sports catalyst flows better than the dense factory unit while still treating exhaust gases
- Designed, developed and manufactured in the UK by Milltek Sport
Fitment
- Audi RS6 C8 4.0 V8 bi-turbo in Performance Edition (Non OPF/GPF Models - USA/ROW Models) (2020 onwards)
- Audi RS7 C8 4.0 V8 bi-turbo (Non OPF/GPF US/ROW Models) (2019 onwards)
- Audi S8 D5 4.0 TFSI V8 Saloon/Sedan - Long Wheel Base (Non OPF/GPF US/ROW Models) (2020 onwards)
- Audi S8 D5 4.0 TFSI V8 Saloon/Sedan - Standard Wheel Base (Non OPF/GPF US/ROW Models) (2020 onwards)
Not suitable for: the Audi RS6 C8 4.0 V8 bi-turbo in Performance Edition (OPF/GPF Models), which needs the Milltek Downpipes & Sports Cats Audi RS6 C8 4.0 V8 bi-turbo OPF/GPF 19+.
Installation
Milltek quotes a fitting time of approx. 3.5 to 4.5 hours. Some versions: Fits to Milltek Sport Catback Back System - Requires Stage 2 ECU Software. Some versions: Fits to OE Cat Back System - Requires Stage 2 ECU Software. This work involves removing parts close to the turbo and engine, so we recommend fitting by a specialist with a ramp and suitable software support.
Upgrade Further
Also available from Milltek for this car: Milltek Front Pipe-back Exhaust Audi RS6 C8 4.0 V8 Bi-Turbo OPF/GPF 19+.
Will it fit the Audi RS7 C8 4.0 V8 bi-turbo (Non OPF/GPF US/ROW Models)?
Yes. Milltek lists this part for the Audi RS7 C8 4.0 V8 bi-turbo (Non OPF/GPF US/ROW Models) as well as the other models in the fitment list above.
Does it fit the Audi RS6 C8 4.0 V8 bi-turbo in Performance Edition (OPF/GPF Models)?
No. For that car, choose the Milltek Downpipes & Sports Cats Audi RS6 C8 4.0 V8 bi-turbo OPF/GPF 19+.
Is it road legal?
Milltek lists this as a race part without EC approval, so it is intended for off-road and competition use.
Do I need a remap?
Yes. Milltek notes: "Fits to Milltek Sport Catback Back System - Requires Stage 2 ECU Software". Without suitable software the engine management is likely to log faults.
Can I use it with my standard exhaust?
It depends on the version. Some are made for the factory (OE) system and others for the Milltek cat-back, so check the notes for the option you choose.
How is a sports cat different from a de-cat?
A sports cat still contains a catalyst, just a less dense one that flows better than the factory unit. A de-cat removes the catalyst completely.
How long does it take to fit?
Milltek quotes approx. 3.5 to 4.5 hours.
What is it made from?
T304L aircraft-grade stainless steel, which is anti-magnetic and resists discolouration better than lower grades.
Is there a warranty?
Yes. Milltek products are covered against defects in materials and workmanship. Contact us with your order number if you have a problem.
