Maximum Flow for the Twin-Turbo M
For the keenest S58 builds, nothing frees the exhaust like going catless. A S58 downpipe of this Katlose design replaces the restrictive factory section and its catalysts straight off the turbos with a wide, open path, letting the twin-turbo six breathe out with as little resistance as possible. It is the most uncompromising flow upgrade for the engine, and it is aimed squarely at owners who want every last bit of exhaust restriction gone.
What Catless Means Here
This is the part to read carefully. Because these pipes remove the catalysts entirely, a set of BMW M4 downpipes like this is intended strictly for off-road or motorsport use where local law allows it. Removing the cats changes how the car must be treated for road use, emissions testing, and inspection, so be honest about where and how you drive and check your local rules first, since it is a choice with real and lasting consequences.
Freed Right at the Turbos
The gain comes from clearing the worst restriction at its source. A set of G80 downpipes opens the bore right where the gas leaves the turbos, so the back pressure crowding them falls away, and the turbos can spin more freely. On a strong engine like the S58, that freer flow sharpens response and gives a supporting tune the room it needs to deliver its full potential.
The Thermal Insulation Option
There is a practical touch worth considering too. A G82 downpipe can be specified with thermal insulation, a wrap or coating that keeps heat inside the pipe rather than letting it radiate into the engine bay. That keeps underbonnet temperatures down, which helps the intake draw cooler air and protects nearby components, a sensible addition on a hard-worked car that generates a lot of heat.
Across the M2, M3, and M4
Because these cars share the S58 and its layout, one design covers the family. A set of M4 downpipes of this kind suits the related models built on the same platform:
- The G87 M2
- The G80 and G81 M3 saloon and touring
- The G82 and G83 M4 coupe and convertible
The Coupe and the Saloon Alike
The same part serves whichever body you have. What a coupe owner fits as G80 M3 downpipes on the saloon is the matching design for the M4 and M2, since the engine and its mounting are shared, so the whole range gets the same uncompromising flow. It means no model is left out of the upgrade, whatever badge it wears.
A Serious Upgrade, Fitted Cleanly
For all they change, the pipes are a direct fit. A set of downpipes M4 owners trust sits in the factory location and connects to the existing system without cutting or fabrication. Confirm your exact model and year before ordering, and plan for the car to be set up correctly afterwards so it runs as it should with the freer exhaust in place from the first drive. Done properly, it is a transformative change to how the engine breathes out under full load.
