CSF Auxiliary Radiator with Integrated Rock Guard for BMW M2 Competition, M3, and M4

Description

The CSF High-Performance Auxiliary Radiator (#8258) is a premium cooling upgrade designed to replace the restrictive and aging factory auxiliary radiators on BMW F8X M3, M4, and M2 Competition models. As vehicles age and power levels increase — especially during track or spirited driving — stock coolers can struggle to maintain optimal fluid temperatures. CSF’s auxiliary radiator addresses this with a larger, high-efficiency core and stronger construction that boosts heat dissipation and helps delay heat soak, improving thermal stability under load. Its drop-in design, robust aluminum build, and integrated rock guard make it both a performance upgrade and a long-term reliability solution.

Fitment Notes

• Designed for BMW F8X M3 (2015–2018) — including CS & Competition variants.

• Fits BMW F8X M4 (2015–2020) — including CS, GTS, and Competition models.

• Compatible with BMW M2 Competition (F87, 2019–2021).

• Sold individually — most applications require two radiators (one for each side).

• Drop-in fit: mounts in factory locations using OEM quick-connect inlet/outlet fittings — no modifications required.

Included

• CSF High-Performance auxiliary radiator with 2-row core.

• Detachable rock guard for front-end debris protection.

• Factory-compatible mounting hardware.

• Installation instructions.

Product Specs

• Core Size Increase: ~7% larger core size vs. OEM.

• Tank Volume Increase: ~10% more volume for improved cooling capacity.

• Core Design: 2-row, 42 mm high-performance core with CSF’s B-Tube Technology.

• Fin Design: Ultra-efficient multi-louvered fins (6.5 mm) maximize airflow and surface area contact.

• Construction: 100% TIG-welded aluminum for durability and thermal efficiency.

• Finish: Satin black for OEM+ appearance behind front grilles.

• Warranty: 2-year limited warranty from CSF.

Product Features

• Significant cooling increase vs. stock: Larger core and tank improve cooling efficiency, reducing heat soak during aggressive driving or track use.

• Modular multi-fit design: Each radiator fits either left or right side, simplifying spares and inventory.

• OEM-style quick-connects: Uses factory mounting points and fittings for straightforward installation.

• Durable all-aluminum construction: TIG-welded design eliminates plastic pod weakness and enhances long-term reliability.

• Integrated rock guard: Protects the core from road debris damage — a common failure point on high-performance driving routes.

• Professional racing and street performance ready: Ideal for boosted performance builds, tuned engines, and extended high-load driving.

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