BMW F8X M3/M4 Equal-Length Exhaust System

Built for Precision. Tuned for Emotion.

The S55 engine inside the F80 M3 and F82/F83 M4 is a marvel of engineering, but the factory exhaust leaves drivers divided. Thin, metallic rasp dominates the sound, muting the depth and richness this platform deserves. At Yonristic, we set out to change that — not just by making the car louder, but by engineering a system that redefines the way the S55 sings.

Exhaust Architecture

The system begins with a 2.75-inch dual midsection, engineered so that each bank of cylinders travels the same distance before merging. This equal-length layout transforms the character of the exhaust note, smoothing the harshness that plagues the stock system and replacing it with a balanced, refined resonance. Midway through, a carefully designed H-style crossover improves exhaust pulse timing and enhances midrange torque, while also giving the note a deeper, fuller texture. From there, gases flow into a 3.5-inch rear section that splits into four outlets, creating a commanding finish both in tone and aesthetics.

Valve-Driven Versatility

At the rear, a dual-path valve system gives you control over the car’s personality. Open the valves and exhaust gases are released through an almost straight-through pathway, delivering a raw, aggressive note with sharp overrun crackles and a rising pitch that builds to an exotic wail. Close the valves and gases are routed into a multi-chamber muffler, engineered with tuned resonators to absorb unwanted frequencies and create a smooth, composed soundtrack for comfortable cruising. Integration with the OEM electronic valve system means instant control with your factory drive modes, but an independent controller is also available for additional flexibility.

Craftsmanship & Materials

The Yonristic F8X Cat-Back is available in two premium constructions: AISI 304 stainless steel for long-term durability, or Grade 5 titanium (Ti-6Al-4V) for those seeking extreme weight savings and sharper tonal character. In titanium form, the system sheds nearly 50 pounds compared to stock, giving the F8X sharper handling dynamics and quicker throttle response. Each system is hand TIG-welded, with every joint polished for smooth internal flow. CNC-machined flanges and hangers, derived from 3D scan data, guarantee an exact factory fit with no cutting, welding, or modifications required.

Visual & Acoustic Presence

The exhaust terminates in quad 4-inch tips, significantly larger than OEM, designed to fill the diffuser perfectly. Offered in polished stainless, black chrome, carbon fiber, or burnt titanium, the tips are both a visual statement and an acoustic tuning element, shaped to sharpen the crispness of the sound at higher revs. From idle burbles to high-RPM shrieks, this system creates a soundtrack that is unmistakably exotic yet unmistakably BMW.

Key Benefits

• 2.75" equal-length midsection for pulse balancing & tonal refinement

• H-crossover for torque enhancement & smoother frequency blending

• 3.5" axle-back section with dual-path valve control

• OEM valve integration with optional independent controller

• Quad 4" tips in multiple premium finishes

• Bolt-on installation with CNC precision fitment

• Hand TIG-welded craftsmanship for strength and beauty

The Yonristic Difference

This isn’t simply an exhaust replacement — it’s a reinvention of how the F8X should sound. By combining motorsport-inspired engineering with artistry in fabrication, we’ve created a system that transforms every drive. Quiet and composed when you need discretion, spine-tingling and exotic when you demand excitement, the Yonristic Cat-Back delivers a level of duality and refinement that the factory system could never achieve.

Your S55 finally has the voice it was born to sing with.