S58 downpipes for the G80 M3, G82 M4 and G87 M2 come in three broad types: race (catless), 200-cell and 400-cell. Race pipes flow the most and are the loudest; 400-cell pipes are the most refined and keep a converter; 200-cell pipes sit in between. Within each type you also choose a diameter, from 3 inch up to 5 inch inlets. The F97 X3M and F98 X4M use the same engine but need their own downpipes, and some of those come with resonators.
Here's what changes when you fit S58 downpipes, how the options compare, and what to plan alongside them.
What Changes with Downpipes on the S58
The S58 is a twin-turbo inline-six, so it has two downpipes, one behind each turbo. From the factory they carry the main catalytic converters. As the IRL listing puts it, the downpipes are the first component in the exhaust, so freeing them up is one of the most effective S58 upgrades. Less backpressure means quicker turbo response and stronger mid-range, and the exhaust note gets deeper and louder, with more turbo sound.
Race vs 200-Cell vs 400-Cell
| Type | Flow | Sound | Examples in stock |
|---|---|---|---|
| Race (catless) | Highest | Loudest, most aggressive | IRL MaxFlow Race, Spool S58 Race, Rvng 3.5", Palenon, STRATEC Titanium |
| Race with resonators | Race-level | Less rasp, deeper tone | IRL MaxFlow Resonated Race |
| 200-cell | Very high | Deeper and louder than stock, less harsh than race | IRL 200-Cell Race |
| 300/400-cell or high-flow catted | High | Most refined | IRL 400-Cell, IRL 3" MaxFlow 400-Cell, STRATEC High Flow Catted |
For more on the trade-offs, see Catless vs Catted Downpipes.
3 Inch vs 3.5 Inch vs 4 Inch vs 5 Inch
Most S58 downpipes are 3 or 3.5 inch. IRL's MaxFlow Race pipes let you choose 3 inch or 3.5 inch, and Rvng's 3.5 inch race pipes keep the full diameter until the last few inches. Larger designs are also available: IRL and Rennelement sell 4 inch hydroformed pipes, and Rvng's HydroFlow pipe uses a 5 inch hydroformed inlet section right after the turbo, where pressure is highest.
Larger pipes have more flow area. On a car with stock turbos and a modest tune, a 3 or 3.5 inch pipe already removes the main restriction (the factory converters). The larger options are aimed at builds chasing more power, often with fuel system upgrades.
G80, G82 and G87 vs X3M and X4M
The G80 M3, G82/G83 M4 and G87 M2 usually share one set of downpipes, though you should still check each listing: some IRL pipes list the G87, some list only the G80 and G82. The F97 X3M and F98 X4M need their own pipes, listed separately. Options for those cars include:
- IRL F97/F98 Resonated Downpipes, which use integrated resonators to cut rasp.
- IRL F97/F98 Catted Downpipes in 200-cell or 400-cell, with integrated heat shields.
- Rvng F97/F98 3.5" Race Downpipes.
Tune Requirement
Downpipes change what the oxygen sensors behind the converters see, and race pipes remove the converters entirely. Several listings recommend a supporting tune, and the brands describe their power figures as coming with proper tuning. Plan the tune at the same time as the hardware; a check-engine light may occur without it.
Catless and high-flow downpipes and other emissions-related parts are intended for off-road and competition use and may not be legal for road use where you live. Check your local laws and inspection rules.
Parts and Tools
- IRL G80/G82 S58 MaxFlow Race Downpipes, 3 or 3.5 Inch — mandrel-bent, choice of size
- IRL G80/G82/G87 S58 200-Cell Race Downpipes — high-flow metallic converters
- IRL G80/G82/G87 S58 400-Cell Catted Downpipes — the refined option
- Rvng S58 HydroFlow 5" Downpipes — hydroformed 5 inch inlet
- Rennelement S58 4in Hydroformed Downpipes — direct bolt-on
- STRATEC S58 Titanium Catless Downpipes — lightweight titanium
- STRATEC S58 High Flow Catted Downpipes — keeps high-flow converters
- O2 Sensor Socket & Thread Chaser Set — for moving the oxygen sensors
Shop by car in BMW M3, BMW M2 and BMW X3, or compare every pipe in Exhaust & Downpipes.
Shop: BMW S58 Downpipes.
Install Overview and Heat Management
Follow the instructions supplied with your pipes; xDrive and rear-wheel drive cars can differ. In general:
- Work on a fully cold car, raised on jack stands or a lift.
- Remove the underbody panels and any heat shields in the way.
- Unplug and remove the oxygen sensors.
- Release the clamps at the turbos and the joints at the midpipe, then remove the factory downpipes and brackets.
- Fit the new pipes loosely, check clearance to the transmission, lines and underbody, then tighten from the turbo back.
- Refit sensors, brackets and panels and check for leaks after a short run.
Removing the converters changes where heat goes. Several pipes include heat shields (the IRL S55 and X3M catted pipes, for example), and you should refit every factory heat shield that clears the new parts. Many listings recommend professional installation.
Frequently Asked Questions
Do S58 downpipes fit both the G80 M3 and the G87 M2?
Many do, but not all. Check the listing's fitment list for your exact car and drivetrain.
Do X3M and X4M downpipes fit the M3?
No. The F97 X3M and F98 X4M have their own downpipes.
Which is quieter, 200-cell or 400-cell?
The 400-cell option is the more refined of the two. IRL describes its 400-cell pipes as keeping a deeper, refined note without the harshness of lower-cell-count cats.
Are resonated downpipes catted?
Not necessarily. The IRL resonated race pipes are race pipes with resonators added to reduce rasp. Check the listing.