ARM Motorsports S58 Catless Downpipe - G80 M3 | G82 / G83 M4

Regular price $547.00 Sale price $497.00
Shipping calculated at checkout.

-2 in stock


• Increase Power and Torque
• Faster Turbo Spool
• Exotic Exhaust Sound
• SS304 Stainless Steel


The ARM S58 Downpipes increase power and torque on your S58-powered BMW while unleashing exotic sounds from your tailpipes.  The ARM S58 downpipes are one of, if not the best all around hardware upgrades for the G8X platform.  The ARM S58 downpipes improve throttle-response throughout the RPM range while stepping up the exhaust note, all without the need to replace the entire catback system on your S58. 

By reducing backpressure on your S58's turbos, you are able to spool faster and hit target boost quicker.  The outcome is more power sooner, resulting in faster 0-60 and 1/4 miles times.  If you are planning to tune your S58, this will benefit your G8X even more, as the backpressure will increase on S58's running higher than OEM boost. Making the ARM S58 downpipes one of the greatest all-around investments for your G8X.   


The ARM S58 Downpipes will increase the overall volume of your exhaust, make the exhaust burbles more audible (even on OEM programming), and make the turbo spool significantly more noticeable.  Check out the links below for some sound clips of our Resonated S58 Catless Downpipes.  


The ARM S58 Downpipes are built with SS304 stainless steel and backed by the ARM Motorsports Lifetime Warranty.  The ARM S58 Downpipes starts with a 3" diameter precision CNC machined turbo v-band flange

S58 Downpipes

Each downpipe utilizes either a Catless Resonator, or a 200-Cell High-Flow Catalyst.  The standard version is the Catless Resonated option.  If you select the Catless Resonated S58 Downpipes, your downpipes will have our resonators installed to help tune the tone of your S58 for a strong and aggressive sound while maximizing exhaust flow.  The resonators are completely hollow on the inside, there is no obstruction whatsoever. 

S58 Downpipes

If you select the catted S58 Downpipes, the catalysts will replace the resonators found in the the catless/resonated downpipes.  The catted version sounds very similar to the catless variant, but will help with some of the exhaust odor.  The catted S58 downpipes will likely still produce a CEL.  To remove a CEL you will need a tune or a CEL Delete Kit. 

The longer downpipe (front downpipe) in the set utilizes a reinforced flex section.  The flex section is incorporated into the long downpipe to relieve stress on the turbo during aggressive driving.

Both ARM S58 Downpipes then transition to a 2.75" 2-Bolt connection to secure seamlessly to the OEM S58 midpipes, or any aftermarket midpipes that connects to the OEM downpipes.

• ARM S58 Downpipes
• Midpipe Connection Mounting Hardware



Make Model Submodel Engine
BMW G80 M3 S58 3.0L
BMW G80 M3 Competition xDrive S58 3.0L
BMW G82 M4 S58 3.0L
BMW G82 M4 Competition xDrive S58 3.0L
BMW G83 M4 S58 3.0L
BMW G83 M4 Competition xDrive S58 3.0L


Every ARM Motorsports product is backed by a lifetime warranty which is automatically issued at the time of purchase. Your warranty protects you against any defects in craftsmanship or fitment. The warranty entitles you to a replacement unit.

This product is for Off-Road Use Only. Items sold for off-road use only are illegal to use on public roads in most states and provinces. This product is intended for racing vehicles which may never be used on a public road. Not for sale in CA.

Please contact us via the contact page form to start a return or exchange. The return/exchange process must be started within 1 week of delivery, after 1 week we will not be able to issue a refund/exchange. A 20% restocking fee will be applied to any return once the order has been shipped. For any questions regarding returns or exchanges feel free to contact us at or reach out to us via the contact form and we would be happy to help.

You can find additional details on our return and exchange policy here.




Horizon Motorsport has one goal: to make our clients happy. We aim to provide the highest level of customer service and the highest caliber parts, all at the most competitive prices. Have a question or concern about a product we sell? Send us an email at


Every piece of carbon fiber that leaves our location in Los Angeles, CA is quality checked extensively prior to shipment. Every piece is backed up by our fitment and finish guarantee.


At Horizon Motorsport our mission is to provide unparalleled customer service. As a small business we pride ourselves on creating long lasting relationships with our customers who know that they can count on us for any of their BMW needs.


Horizon Motorsport was founded in 2019 in Los Angeles, CA by fellow BMW enthusiasts. We have experience with nearly all makes and models and have been actively involved in the Southern California BMW scene for over 3 years. Because of our unique insight into the BMW community, we choose to carry only the highest quality parts from the highest quality brands on the market.