CSF 8321 Auxiliary Radiator for 2021-2025 BMW G8X M3 / M4 / M2

Vehicle Fitment

• 2021-2025 BMW M3 (G80 / G81) - S58 3.0L
• 2021-2025 BMW M4 (G82 / G83) - S58 3.0L
• 2022-2025 BMW M2 (G87) - S58 3.0L

Features

• 2-row core with CSF's B-Tube technology for superior heat transfer
• 42 mm thick core to increase coolant capacity and thermal efficiency
• 5 mm tall multi-louvered fins maximize airflow and surface area contact
• All-aluminum TIG-welded construction - core and tanks
• OEM-style quick-connect inlet/outlet for drop-in installation
• Includes detachable rock guard to protect against debris damage
• Satin black finish for an OEM-stealthy and durable look
• Individually pressure- and leak-tested for reliability
• 2-year limited warranty from CSF

Specifications

• Part Number: 8321
• Core Rows: 2
• Core Thickness: 42 mm
• Tube Type: B-Tube
• Construction: All-aluminum (core + tanks)
• Flow Style: Cross-flow / OEM routing

Included Components

• 1x CSF 8321 auxiliary radiator
• Mounting/bracket hardware (OEM-style pins)
• Installation & specification sheet

Product Description

The **CSF 8321** is a high-performance auxiliary radiator designed specifically for the BMW G8X platform (M3, M4, M2) with the S58 engine. It complements the factory cooling setup by providing increased coolant volume and enhanced heat rejection - crucial for track driving or high-power builds.

With a 2-row, 42 mm core using CSF's efficient B-Tube design and tall multi-louver fins, this radiator improves thermal stability and helps prevent overheating during aggressive driving. The all-aluminum construction ensures durability, and the drop-in design means it installs easily using OEM Quick Connect lines and factory mounting points.

Whether you're pushing the limits of your S58 or looking for better heat management under track sessions, the 8321 auxiliary radiator provides a reliable performance upgrade. Its robust build and CSF's testing standards give both street and track drivers confidence that their cooling system can handle the load.