MAD 300-Cell Race Catted Downpipes | BMW F90 M5 | F91/F92/F93 M8 W/ No CEL Guarantee

MAD 300-Cell Race Catted Downpipes

BMW F90 M5 | BMW F91/F92/F93 M8

Improve exhaust flow, turbo response, and sound while retaining high-flow catalytic converters with the MAD 300-Cell Race Catted Downpipes. Designed for S63-powered BMW M5 and M8 models, these downpipes replace the restrictive factory primary downpipes with a performance-focused, direct-fit upgrade.

Constructed from premium 304 stainless steel, each downpipe is engineered to withstand extreme exhaust temperatures while providing long-term strength and durability. Smooth bends and optimized transitions help reduce backpressure, improve turbo spool, and support stronger throttle response.

The integrated 300-cell high-flow catalytic converters provide a balance between increased performance, aggressive sound, and everyday drivability. MAD also includes a limited No CEL Guarantee for catalytic-converter-related check-engine lights.

Product Features

• Premium 304 stainless-steel construction
• Integrated 300-cell high-flow catalytic converters
• Increased exhaust-flow capacity
• Reduced exhaust backpressure
• Supports quicker turbo spool
• Improved throttle-response potential
• Deeper and more aggressive exhaust tone
• Designed to minimize unwanted drone
• Integrated flex sections for added durability
• Compatible with right-hand-drive and left-hand-drive vehicles
• Direct bolt-on installation
• No cutting or welding required
• Compatible with factory and aftermarket exhaust systems
• Spot-on vehicle-specific fitment
• Lifetime warranty against manufacturing defects and fitment issues
• 90-day return period

Performance Benefits

• Potential gains of up to 30 horsepower with factory turbochargers
• Additional power potential with upgraded turbochargers
• Improved exhaust flow
• Faster turbocharger response
• More aggressive exhaust sound
• Increased horsepower and torque potential

Actual performance results depend on tuning, fuel, supporting modifications, vehicle condition, and testing method.

No CEL Guarantee

MAD provides a one-year No CEL Guarantee from the original purchase date.

If a check-engine light occurs specifically because of a catalytic-converter efficiency fault, MAD states that the affected downpipe will be replaced at no charge under the terms of its guarantee.

The lifetime warranty remains applicable to qualifying manufacturing defects, including cracks in the piping or welds.

The No CEL Guarantee does not necessarily cover warning lights caused by oxygen sensors, wiring, installation errors, exhaust leaks, tuning, or unrelated vehicle faults.

Vehicle Fitment

• BMW M5 (F90)
• BMW M8 Convertible (F91)
• BMW M8 Coupe (F92)
• BMW M8 Gran Coupe (F93)

Engine: S63 Twin-Turbo V8

Important Legal Notice

Race use only.

High-flow catalytic converters do not guarantee emissions compliance or road legality. Local emissions and vehicle-equipment laws vary, and the purchaser is responsible for confirming legal use in their location.

Availability

In Stock & Ready to Ship

Orders generally ship within 1–2 business days.

Installation

Professional installation by a qualified BMW performance shop is strongly recommended. Proper exhaust alignment, leak inspection, oxygen-sensor installation, and clearance verification are required.

Uproar Customs does not provide installation instructions, tuning, emissions-compliance advice, or technical support for self-installation.