The ARM S58 Midpipe upgrade unleashes the exhaust sound of your G80 M3 or G82/G83 M4. By removing the secondary catalysts and the two middle resonators, it dramatically opens up your S58 — while retaining the OEM muffler so you keep full control of the exhaust valves. Close them for a subtle tone, or open them for maximum sound.

Highlights

• Exotic exhaust sound with more audible burbles, even on OEM tuning.
• Choice of X-Pipe or H-Pipe design.
• Fits the OEM underbody brace — no larger brace needed.
• 3" design in SS304 stainless steel.
• Saves 15 lbs over OEM.

Construction

A 3" design from the downpipe connection that reduces to 2.75" at the rear to meet the OEM muffler. It starts with an OEM-style 2-bolt flange (mates to OEM or upgraded downpipes) sized for the OEM midpipe gasket, then transitions via slip-fit connections to the X-Pipe or H-Pipe merge section — where each bank's sound waves combine for a richer, more exotic note. Secured with a standard hanger prong on the driver's side and the OEM-style bracket on the passenger's side.

Options

• ARM S58 Crossover Pipe — replaces the heavy OEM crossover for more sound and saves an additional 4 lbs.
• Axle-back adapters — step down from 3" (76mm) to 2.75" (70mm) to fit most aftermarket axle-back systems.

Fitment (S58 3.0L)

BMW G80 M3, G82 M4, G83 M4 (incl. Competition xDrive).

What's included: 2x front midpipe sections, 1x X-Pipe/H-Pipe, 4x sleeve clamps (ARM S58 Crossover Pipe optional).

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

Emissions disclaimer: This product is intended for off-road, race, or closed-course competition use only and is not legal for use on pollution-controlled vehicles operated on public roads in most states and provinces. You are responsible for compliance with all applicable emissions 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.