Milltek Non-Resonated Secondary Cat Bypass | BMW G8X M3 M4

Description

The Milltek Axle Back Non-Resonated Secondary Cat Bypass is engineered for BMW G8X M3 and M4 models (S58 engine). This performance component replaces the factory secondary catalyst, delivering improved exhaust flow and a sharper acoustic character. Direct fitment to OE downpipes and OE axle-back systems—no modification required. Hand-finished T304L stainless steel construction with mandrel-bent 76.20mm (3.00") primary bore. Non-resonated design eliminates the OE resonance chamber for full-throttle note clarity. CNC-formed flanges ensure precise factory alignment and OEM hanger compatibility. • Fitment: BMW G8X M3 (G80) and M4 (G82/G83) with S58 engine • Material: T304L stainless steel, hand-finished • Bore: 76.20mm mandrel-bent primary • Configuration: Non-resonated secondary cat bypass • Install: Direct replacement—uses factory mounting points and OEM hangers • Sound character: Aggressive full-throttle note, reduced mid-range resonance Engineered for serious track and closed-course driving. Fits OE system. Designed and manufactured in the UK with 40+ years of performance exhaust heritage. Tested at the Nurburgring.

Fits 14 vehicles including:

• 2021 BMW M3— G80 M3 & M3 Competition S58 3.0 Turbo > 2021 and Later
• 2022 BMW M3— G80 M3 & M3 Competition S58 3.0 Turbo > 2021 and Later
• 2023 BMW M3— G80 M3 & M3 Competition S58 3.0 Turbo > 2021 and Later
• 2024 BMW M3— G80 M3 & M3 Competition S58 3.0 Turbo > 2021 and Later
• 2025 BMW M3— G80 M3 & M3 Competition S58 3.0 Turbo > 2021 and Later
• 2026 BMW M3— G80 M3 & M3 Competition S58 3.0 Turbo > 2021 and Later
• + 8 more vehicles