OVERVIEW

Active Autowerke Signature catted downpipes for the BMW G80 M3 and G82 M4 — cars praised for their performance but muffled from the factory, with a restrictive S58 downpipe that slows the evacuation of spent exhaust gases and turbo spool. The Signature downpipe uses 3" stainless steel piping and stainless flex joints for more power, quicker spool and extreme durability, stepping down to 70mm to meet the OEM exhaust and never below that stock diameter. Its pair of 4.5" ultra high flow GESI G-Sport catalytic converters use proprietary precious metal loading to cut emissions and back-pressure without setting a CEL, and join Active Autowerke's mid-pipe and valved rear axle-back exhaust to transform the sound of the car.

SPECS

3.00" diameter 304 stainless steel downpipe piping, stepping down to 70mm at the OEM exhaust connection (never smaller than the 70mm stock diameter)
Stainless steel flex joints
Pair of 4.5" GESI G-Sport Ultra High Output catalytic converters
400 cell per square inch ultra high flow catalyst
Full 304 stainless steel catalytic converter construction including the substrate; substrate furnace-brazed to the mantle
Cast upper stainless steel V-band flange for precise fitment
TIG welded 304 stainless steel construction
Catalytic converters rated for 500 to 850 horsepower per cat
Withstands up to 1500 °F
Reaches operational efficiency within 9 seconds of start-up
No check engine light when using these downpipes
GESI converters are EPA registered and fully OBD2 compliant for 1996 and newer vehicles in 49 states (not California)
Bolts on with no cutting or welding required
5 year / 50,000 mile warranty on the catalytic converters
Made in Miami, Florida

PARTS INCLUDED

Pair of Active Autowerke Signature catted downpipes with GESI G-Sport Ultra High Output catalytic converters
Complete kit as supplied by Active Autowerke; see the installation instructions for the full bill of materials.

TECH RESOURCES

Additional Parts Required

None. Active Autowerke specifies no additional hardware for this part — the downpipes bolt to the OEM turbo outlets and the OEM exhaust connection.
Optional, to complete the Active Autowerke G80/G82 exhaust system: Signature Mid-Pipe with X-Pipe, Signature Single Mid-Pipe and the Valved Rear Axle-Back Exhaust.

Installation

Active Autowerke catalytic converter break-in instructions (PDF) — follow this procedure on first start-up to avoid a check engine light being set in error.
Active Autowerke does not publish a downpipe-specific installation PDF for this part number. Contact Speed Logic with fitment or installation questions.

Notes

Please Note: These catalytic converters are not legal for use on vehicles registered in the state of California as a result of California Vehicle Code Section 27156 and 38391.
NOTE: Federal law prohibits the tampering of an emissions control device. Mobile Source Enforcement Memorandum 1A allows for aftermarket parts to be used in the repair or replacement of emissions control systems, provided the emissions are not adversely affected. There is no mention or reference to cell density or converter volume dimension. The GESI catalytic converter will produce emissions that will meet the standards set by the EPA, not CARB.

PART NUMBER

11-085

VEHICLE APPLICATIONS

Make	Model	Chassis	Engine	Years
BMW	M3	G80	S58 3.0L Twin-Turbo I6	2021+
BMW	M4	G82	S58 3.0L Twin-Turbo I6	2021+