CSF High-Performance Heat Exchanger – BMW 230i / M240i / 340i / 440i (F-Chassis, B48/B58)

OVERVIEW

CSF's high-performance heat exchanger is the definitive charge-cooling upgrade for the F-Chassis BMW B58 and B48. It replaces the OEM single-row 26mm unit with what CSF calls the world's largest 2-row core — 68mm deep, built on CSF's B-Tube technology and finished with a 6.5mm multi-louvered fin. A triple-pass flow structure routes the charge coolant across the core three times before it exits, dropping intake air temperatures and shortening heat-soak recovery between pulls.

Tapered entry and exit points at the end tanks were developed after extensive wind-tunnel, dynamometer and field testing to optimize water flow and match OEM flow spec. The resulting airflow improvement benefits the rest of the cooling system too — particularly on xDrive cars, where the factory transmission oil cooler sits directly in front of the heat exchanger.

The unit is CNC-machined for a true plug-and-play fit with quick-connect fittings, OEM-style mounting pins and brackets, and a detachable rock guard to protect the core. This listing offers the satin black finish (CSF #8131B) and the polished finish (CSF #8131) — select your finish above.

SPECS

• Core dimensions: 524mm L × 478mm H × 69mm W
• 68mm 2-row core with CSF's B-Tube technology — CSF's largest 2-row core
• 6.5mm multi-louvered fin height
• Triple-pass flow design
• Compared with the OEM 1-row 26mm core, a substantial increase in core fluid capacity
• Tapered inlet/outlet entry and exit points at the end tanks for optimized water flow (matches OEM spec)
• Detachable rock guard included
• CNC-machined OEM-style mounting pins and brackets
• CNC-machined quick-connect fittings; direct plug-and-play installation with no modifications required
• Includes a hardware mounting kit for applications with a factory transmission oil cooler mounted in front of the heat exchanger (xDrive models)
• Finishes sold on this listing: semi-gloss/satin black (CSF #8131B) or polished (CSF #8131)
• Replaces OEM part number 17118741830
• CSF 2-year warranty, under normal use and service, to the original purchaser of the vehicle in which the product was originally installed

PARTS INCLUDED

• One (1) CSF high-performance heat exchanger in the selected finish — satin black (#8131B) or polished (#8131)
• Detachable aluminum rock guard
• Hardware mounting kit for applications with a factory transmission oil cooler mounted ahead of the heat exchanger
• Complete kit as supplied by CSF Radiators; CSF does not publish a full bill of materials for this part — see the instructions packed in the box.

TECH RESOURCES

Additional Parts Required

• None. CSF Radiators specifies no additional hardware for this part — it is a direct-fit replacement and the mounting kit needed for xDrive cars with a front-mounted transmission oil cooler is supplied in the box.
• Installer-supplied: fresh BMW-spec coolant for the charge-air circuit to refill and top off after the swap, plus a drain pan.

Installation

• CSF does not publish a downloadable installation PDF for this heat exchanger. Printed installation instructions are packed in the box.
• Installation uses the OEM mounting pins, brackets and quick-connect fittings; no cutting, drilling or line modification is required.
• On xDrive cars the supplied hardware kit relocates and secures the factory transmission oil cooler ahead of the larger core — fit it as part of the same job.
• Bleed the charge-cooling circuit fully after refilling before the car is driven hard.
• Need help before or during the install? Contact Speed Logic and we will walk you through it.

Notes

• Fitment above follows CSF's published application data for #8131 / #8131B. Confirm your exact chassis, engine and model year with Speed Logic before ordering.
• Satin black #8131B and polished #8131 are the same part in different finishes — both are selectable on this listing.

PART NUMBER

• CSF #8131B — satin black finish
• CSF #8131 — polished finish

VEHICLE APPLICATIONS