BMW M5 F90 / M8 F92 Straight Catback Stainless Steel Exhaust System

Engineered for BMW M5 F90 and M8 F92 Coupé owners, this Straight Catback Stainless Steel Exhaust System replaces the OEM Valvetronic muffler with a valveless flow-oriented straight geometry — delivering an aggressive motorsport sound character and reduced backpressure. Manufactured in Europe and quality-controlled by BYC Performance, this system fits the F90/F92 platform.

The F90 M5 + F92 M8 share the same S63B44T4 4.4L V8 biturbo (600-625 hp) and identical catback geometry. Unlike the Valvetronic variant, the straight catback has no electronic flap management — the system always runs in full-flow mode. This delivers a louder, more aggressive and constantly motorsport-grade tone. Daily-driver tolerance for the sound is required.

Key Features

• Valveless Straight-Flow Geometry: No electronic flap, constant maximum flow, constant motorsport sound character.
• T304 Stainless Steel: Corrosion-resistant, lifetime rust-resistance.
• Lower Backpressure: Less flow restriction than the Valvetronic muffler, marginal power gain.
• Constant Aggressive Tone: Louder than the Valvetronic variant's valve-open mode — track DNA.
• CNC-Bent Piping: Smooth internal surface, flow-optimized geometry.
• OEM Mid-Pipe V-Band: Direct bolt-on, no welding.
• OEM Hanger Compatible: Direct bolt-on fit to factory exhaust hangers.

Straight Catback vs. Valvetronic Catback — Which?

This is the straight catback version — compared with the Valvetronic variant:

• Straight Catback (this product): Constant full flow, constant aggressive motorsport tone, marginal power gain, lower price (no electronic control box)
• Valvetronic Catback: Remote dual-mode — valve closed OEM+ daily, valve open tonal track. Higher price, includes control box.
• For a constantly aggressive sound: straight preferred
• For daily-friendly modulation: Valvetronic preferred

Vehicle Fitment

This BMW M5 F90 / M8 F92 straight catback fits the following models:

• BMW M5 F90 Sedan (2018-2024) — S63B44T4 600 hp
• BMW M5 F90 Competition (2018-2024) — 617 hp
• BMW M5 F90 CS (2021 limited) — 625 hp
• BMW M5 F90 LCI (2020-2024)
• BMW M8 F92 Coupé (2019-2025) — S63B44T4 600 hp / 617 hp Competition

Important notes:

• BMW M8 F93 Gran Coupé and F91 Convertible share the S63B44T4; catback geometry is likely compatible — verify bumper cutout before ordering.
• NOT compatible with the BMW M5 F10 / M6 F06 (S63B44T2).
• NOT compatible with the BMW M5 E60 (S85 V10).
• The straight catback produces constant high sound; street-legality tolerances may apply.

Technical Specifications

• Material: T304 Stainless Steel
• Configuration: Straight catback (valveless, constant full flow)
• Exit Tips: OEM-compatible twin exits
• Sound Character: Constant aggressive motorsport (constantly and noticeably louder than OEM)
• Connections: Mid-pipe v-band + rear hanger
• Origin: Europe

Installation Notes

1. Lift the vehicle, loosen rear bumper underbody screws.
2. Release the stock Valvetronic catback mid-pipe v-band clamp.
3. Disconnect the OEM Valvetronic actuator electrical connector (lambda spacer or tune may be needed to suppress MIL).
4. Replace OEM exhaust hangers if worn.
5. Hang the new straight catback, torque v-band (12 Nm).
6. Confirm tips are centered in the bumper cutout.

Care & Maintenance

T304 stainless is corrosion-resistant. Wipe tips with a soft cloth. Re-check bolt torque after first 500 km.

FAQ

How does this differ from the Valvetronic catback?
The straight catback has no electronic flap; constant full flow and constant aggressive tone. The Valvetronic catback is remote-controlled dual-mode.

How loud is it?
Constantly and noticeably louder than OEM. Aggressive motorsport character.

Does it cause OBD-II faults?
If the Valvetronic actuator connector is disconnected, MIL may appear; lambda spacer or tune resolves this.

Does it fit the F10/F06?
No.

Does it fit the E60?
No.

Does it fit the M8 F93 / F91?
Same S63B44T4; catback geometry likely compatible. Verify before ordering.

Welded or direct bolt-on?
Direct bolt-on. V-band clamp + hanger system.

Shipping time?
1-3 business days via partner couriers.

Warranty?
BYC Performance offers a 12-month manufacturer warranty.

Why BYC Performance?

BYC Performance is a Turkey-based performance tuning specialist sourcing premium exhaust parts from leading European manufacturers. Our catalog includes BMW M5 F90 straight catback, BMW M8 F92 catback, BMW M stainless exhaust, and more.