Milltek Axle Back Secondary Catalyst Bypass system for BMW G8X M3 and M4. Direct fitment 102mm single mid-pipe with X-pipe configuration. Non-resonated design for closed-course and track use. Connects to either OE axle back (SSXBM1342) or Milltek Cat-Back Axle Back (SSXBM1341).
Mandrel-bent T304L stainless steel construction with hand-finished welds. Removes secondary catalyst restrictions post-turbocharger for improved turbo efficiency and mid-range response. Engineered to work seamlessly with both OEM and Milltek exhaust systems. Uses OE mounting points and hangers—no modification required.
- Fits BMW G8X M3 (S58 engine) with OE or Milltek axle-back systems
- Fits BMW G8X M4 (S58 engine) with OE or Milltek axle-back systems
- Non-resonated: optimized for track and closed-course driving
- 102mm bore mandrel-bent X-pipe design
- T304L stainless, TUV tested for durability
Designed and manufactured in the UK with 40+ years of performance exhaust heritage. Tested at the Nurburgring.
Fitment
- BMW 3 Series G80 M3 & M3 Competition S58 3.0 Turbo 2021 and Later
- BMW 4 Series G82 M4 & M4 Competition S58 3.0 Turbo 2021 and Later
Key Facts
- Pipe diameter: 101.60mm
- Fitting time: 1.5 to 2 hours to fit (including removing OE system)
- Race product: Yes
- E-marked: No
SHIPPING
All items are subject to a handling period before they are dispatched. 99% of orders leave the warehouse within 1-3 days of payment. We will notify you by email when your items have been shipped. Most items should be received within 3-7 business days of your order date. This may be longer for international delivery.
* DELIVERY TIME= Processing Time + Shipping Time
* These shipping times are estimates, not guarantees but we always strive to get your order to you as soon as possible.
Shipping Costs:
● Shipping fees are calculated at checkout based on your location and the chosen shipping method.
Order Tracking:
● Once your order ships, you will receive a confirmation email with a tracking number and a link to monitor your shipment's status.
International Shipping:
● We ship internationally to selected countries. Rates and delivery times vary by destination.
Customs Fees and Import Duties:
● International orders may incur customs duties and taxes, which are the customer's responsibility. Please check with your local customs office for details.
Lost or Damaged Shipments:
● We are not liable for packages that are lost or damaged during shipping. For damaged items, please contact the shipping carrier to file a claim.
Customer Service Contact:
● For any questions regarding shipping, reach out to our customer service team at sales@sbxperformance.com
RETURN/REFUND POLICY
We have a 30-day return policy, which means you have 30 days of purchase your item to request a return.
To be eligible for a return, your item must be in the same condition that you received it, unworn or unused, with tags, and in its original packaging. You’ll also need the receipt or proof of purchase.
-Returns accepted within 30 days of purchase if the item is unused and in original packaging.
-Customer is responsible for return shipping unless the product is defective.
-Refunds processed within 5-7 business days after receiving the returned item.
To start a return, you can contact us at sales@sbxperformance.com.
If your return is accepted, we’ll send you a return shipping label, as well as instructions on how and where to send your package. Items sent back to us without first requesting a return will not be accepted.
You can always contact us for any return question at sales@sbxperformance.com.
Damages and issues
Please inspect your order upon reception and contact us immediately if the item is defective, damaged or if you receive the wrong item, so that we can evaluate the issue and make it right.
Exceptions / non-returnable items
We do not accept returns for hazardous materials, flammable liquids, or gases. Please get in touch if you have questions or concerns about your specific item.
Unfortunately, we cannot accept returns on sale items or gift cards.
Exchanges
The fastest way to ensure you get what you want is to return the item you have, and once the return is accepted, make a separate purchase for the new item.
European Union 14 day cooling off period
Notwithstanding the above, if the merchandise is being shipped into the European Union, you have the right to cancel or return your order within 14 days, for any reason and without a justification. As above, your item must be in the same condition that you received it, unworn or unused, with tags, and in its original packaging. You’ll also need the receipt or proof of purchase.
Refunds
We will notify you once we’ve received and inspected your return, and let you know if the refund was approved or not. If approved, you’ll be automatically refunded on your original payment method within 10 business days. Please remember it can take some time for your bank or credit card company to process and post the refund too.
If more than 15 business days have passed since we’ve approved your return, please contact us at sales@sbxperformance.com.
