Audi C8 4.0T Downpipes - C8 RS6/RS7 D5 A8/S8

The ARM C8 4.0T Downpipes immediately increase power, torque and throttle response on your C8 RS6, RS7 or D5 S8/A8. By reducing exhaust back-pressure, they let the 4.0T turbos spool faster for more power and torque — especially low in the rev range — and an incredible sound. The OEM downpipes use two large catalysts that choke flow; the ARM downpipes remove that restriction.

Highlights

• Gains of up to 41 whp / 45 wtq.
• Faster turbo spool and an improved exhaust note.
• Fully reversible.
• Removable midpipe flanges for easier installation.

Construction

Built from SS304 with a 5.75" CNC-machined V-band flange at the turbos (connects to OEM or upgraded turbos using the same exhaust-side housings), with a centering key to line up perfectly with the OEM or ARM C8 midpipes. The body holds a full 5.5" until it turns toward the midpipes, gradually reducing to 3". A removable midpipe flange saves serious install time — secure it to the midpipe first, then connect with a single, easy-to-reach exhaust clamp.

Fitment (4.0T)

Audi C8 RS6, C8 RS7, D5 S8, D5 A8.

What's included: 2x downpipes, 2x midpipe flanges, 2x exhaust clamps, 2x midpipe gaskets, 6x midpipe bolts, 6x midpipe nuts.

Backed by ARM Motorsports' lifetime warranty against defects in craftsmanship and fitment.

Emissions disclaimer: This product is not legal for sale or use on pollution-controlled vehicles operated on public roads and is intended for off-road, race, or closed-course competition use only. You are responsible for compliance with all applicable emissions laws; use on public roads may violate the Federal Clean Air Act (42 U.S.C. § 7522) and similar state laws. Please check your local laws before purchase and installation.

Ships from our Vancouver shop — KORE SPEED is proudly Canadian-owned, with no surprise cross-border duties for Canadian buyers. Questions on fitment? Email support@korespeed.com.