Genuine BMW F80 M3, F82/F83 M4 & F87 M2 Competition S55 Downpipe Single Flange

The Genuine BMW S55 Downpipe Single Flange (18327850430) is the OEM exhaust flange used to connect and seal the downpipe to the mid-section of the exhaust on the BMW F80 M3, F82/F83 M4 and F87 M2 Competition fitted with the S55 twin-turbo engine. Manufactured to BMW's original specifications, this genuine replacement flange provides a precise, gas-tight joint for reliable exhaust performance.

On the S55 exhaust, this single flange forms part of the downpipe connection and is commonly disturbed whenever the downpipe is removed. Heat cycling, corrosion and age mean the original flange and its seal are often damaged during removal, so BMW specialists frequently recommend replacing it whenever the downpipe comes off – especially when fitting a sport or decat downpipe.

Whether you're installing an aftermarket downpipe, repairing your exhaust or refreshing a factory system, genuine BMW hardware ensures correct fitment, a proper seal and long-term reliability.

Key Features

• Genuine BMW OEM S55 downpipe exhaust flange (single flange)
• BMW part number: 18327850430
• Connects and seals the downpipe to the exhaust mid-section
• Engineered for the S55 twin-turbo exhaust system
• Ensures a leak-free, correctly aligned exhaust joint
• Direct replacement for the factory flange
• Manufactured to BMW OEM specifications
• Ideal when fitting sport or decat downpipes
• Genuine BMW quality and fitment

Essential When Fitting or Replacing Downpipes

The downpipe flange provides the sealing face and alignment for a gas-tight exhaust connection.

Benefits include:

• Correct exhaust alignment
• Leak-free downpipe-to-mid-section joint
• Easier, more accurate installation
• Secure exhaust assembly
• OEM-quality fitment

Commonly Damaged During Removal

Due to its exposed location, the downpipe flange is subjected to:

• Extreme heat cycles
• Road salt and corrosion
• Moisture ingress
• Repeated thermal expansion

As a result, it can seize, warp or fail to reseal once disturbed. Replacement is recommended whenever the downpipe is removed, a decat or sport downpipe is fitted, or exhaust repairs are carried out.

Genuine BMW OEM Quality

Unlike generic alternatives, genuine BMW hardware is manufactured to the exact standards required by the S55 exhaust system.

• Factory-correct dimensions
• Proper sealing face
• Correct material specification
• Long-term durability
• Direct OEM fitment

Product Specifications

• Manufacturer: BMW
• Part Number: 18327850430
• Component: Exhaust Flange (Single Flange)
• Application: Downpipe to exhaust mid-section connection
• Engine: S55 (twin-turbo 3.0L)

Compatibility

Designed for BMW M models with the S55 engine, including:

• BMW F87 M2 Competition (2016–2021)
• BMW F80 M3 & M3 LCI (2012–2018)
• BMW F82 M4 & M4 LCI (2013–2020)
• BMW F83 M4 Convertible & M4 LCI (2013–2020)

Please verify compatibility using your VIN or original part number before ordering.

What's Included?

• 1x Genuine BMW S55 Downpipe Single Flange (18327850430)

Purchase quantity required depends on your specific exhaust configuration.

Why Choose Genuine BMW Parts?

• Factory-correct fitment
• Proper exhaust sealing
• Long-term durability
• OEM material quality
• Reliable exhaust performance

Why Buy from R44 Performance?

R44 Performance supplies genuine BMW OEM parts trusted by enthusiasts and workshops worldwide.

• BMW specialists
• Genuine BMW components
• Fast UK & worldwide shipping
• Expert technical support

Complete your downpipe installation correctly with the Genuine BMW S55 Downpipe Single Flange 18327850430 – the ideal OEM replacement when fitting or refreshing your F80 M3, F82/F83 M4 or F87 M2 Competition exhaust.

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