The ARM S58 Midpipes will not only increase the overall volume of your exhaust but also transform the sound into something truly unique from an ordinary G80 M3.  It will also make the exhaust burbles more audible even with OEM tuning.

CONSTRUCTION

The ARM S58 Midpipes are a 3" designfrom the downpipe connection all the way to the rear section where it will reduce to 2.75" to perfectly connect to the OEM muffler section.  The ARM S58 Midpipes start with a OEM-style 2-Bolt flange which can mate up to either the OEM downpipes, or upgraded downpipes that fit the OEM exhaust.  These flanges will accommodate the OEM midpipe gasket perfectly.  Alternatively, you can choose to upgrade your S58's crossover pipe with the ARM S58 Crossover Pipe.  The optional ARM S58 Crossover Pipe replaces the heavy OEM pipe to open up more sound and saves an additional 4lbs.

The ARM S58 Midpipes then transition to the X-Pipe or H-Pipe section of the exhaust via the slip-fit connections on either side.  Where the exhaust merges is the heart of the ARM S58 Midpipes where you have the choice between X-Pipe or H-Pipe and is where the magic happens.  The sound waves of each bank of your S58 engine are combined to produce a much more exotic and richer exhaust note. The X-Pipe or H-Pipe section lives above the OEM brace with ample clearance, there is no need to install a larger brace. 

The ARM S58 Midpipes will secure to the exhaust hanger on the driver's side using a standard exhaust hanger prong.  It is secured to the passenger's side using the OEM style mounting bracket.  These help the exhaust from jostling around during aggressive driving.

The ARM S58 Crossover Pipe removes the extra casting material and sound deadening of the OEM S58 crossover pipe, allowing an increase in sound your S58 produces.  The G82 M4 in the video below is equipped with the ARM S58 Midpipe, S58 Crossover Pipe, and ARM S58 Downpipes, providing an increase in volume over the OEM setup.  Pairing the ARM S58 Midpipes with the ARM S58 Downpipes will increase the overall volume of your S58 significantly more than the ARM S58 Crossover Pipe alone.  

AXLE BACK ADAPTERS

The ARM S58 Axle Back Adapters are designed to reduce down at the end of the midpipe to fit most aftermarket axle back systems. Most aftermarket axle back systems reduce down from 3" (76mm) to 2.75" (70mm) and that's where the ARM S58 Axle Back Adapters come in.