B58 4.5" Downpipe

Our first B58 Product is now finally live. 

It may seem excessive, but we spent a better part of a year running this downpipe on our own M240i to ensure performance, reliability, avoidance of CEL's is guaranteed.

While the market for B58 downpipes is addmitedly saturated, the craftsmanship of our OEM fitment B58 downpipe simply cannot be beat. In a sea of rebranded offshore downpipes and overpriced options with mediocre fabrication and welding, our objective was to make the choice simple.

We CNC machine both the Turbine flange as well as the lower transition / slip fit section in-house from billet stainless, sourced in Canada. Each downpipe is fitup by hand, and expertly positioner TIG welded for a finished product that is as beautiful as it durable, with an enjoyable exhaust note that is Careful design consideration was given for the the most gradual and laminar reduction in diameter possible, without abrupt steps between different diameters.

• GSI G-sport Gen 2 850hp EPA compliant catalyst ensures effective emissions function without robbing power
• Validated and guaranteed to not trigger a check engine light on fully OEM calibration
• Smooth flowing transitions from start to finish
• Up to 20Ft*lb additional torque through the midrange without tuning
• Tested to 500WHP in stage 3 configuration 
• Includes brand-new OEM BMW Turbine side crush gasket

Secondary O2 sensor bung is not pictured on the protoype pieces shown, but is included with every catalyst / downpipe built.

***Please note- Race pipe option listed is not for use on public roads, or in any other situation outside of closed-course motorsports. This is not a technicality, expect to have to prove your race application upon purchase.***

All prices are listed in USD.  

Orders are shipped from our facility in British Columbia, Canada, with the exception of select Garrett turbochargers which may ship directly from our supplier located within the United States.

International shipments may be subject to customs duties, taxes, and/or tariffs which are based on recipient shipping location and are not included in your total.  Any additional charges relating to this will be the sole responsibility of the recipient and will be payable to the applicable local tax authorities prior to delivery.