CSF BMW 135I (E8X) / 335I (E9X) / 1M (E82) N54 Racing Radiator

The factory radiator on N54-powered 135i, 335i, and 1M models relies on plastic end tanks and connections - a genuine weak point, especially on track cars where sustained heat makes the plastic brittle and prone to cracking and leaking over time. CSF's All-Aluminum Racing Radiator eliminates that weakness entirely, replacing the factory design with a fully aluminium core and construction throughout.

At the heart of the design is CSF's exclusive B-Tube technology - rather than a single oval radiator tube, CSF uses two tubes shaped like a "B" for genuinely more surface area and greater strength, while allowing for a thinner, lighter, more thermally efficient material than a conventional single-tube design. The core is paired with 6.5mm tall, ultra-efficient multi-louvered fins for maximum surface area contact, and CNC-machined quick-connect inlet/outlet fittings maintain a precise seal. Every unit is individually leak tested and receives a 30-point inspection before shipping.

Please select your transmission type at checkout: available as #7045 (manual transmission) or #7046 (automatic/DCT) - these are separate, non-interchangeable radiators, so selecting the correct one is essential.

Why Choose This Radiator

• CSF's exclusive B-Tube core technology - more surface area and strength than a conventional single-tube design
• Eliminates plastic end tanks and connections - addresses the factory design's main failure point
• 6.5mm multi-louvered fins - maximised surface area for efficient heat rejection
• CNC-machined quick-connect fittings - precise, secure seal at the inlet/outlet
• True drop-in fit - uses factory plastic shrouding, hose connections, and mounting points
• Individually leak tested with 30-point inspection - genuine quality control before shipping

Compatibility

• BMW E82 1M (2011, N54, manual transmission - #7045)
• BMW E82/E88 135i (2008-2011, N54, manual - #7045 / automatic - #7046)
• BMW E90/E92/E93 335i/335xi (2007-2011, N54, manual - #7045 / automatic - #7046)

Fitment note: the thicker core tightens tolerances slightly between the expansion tank and accessory belt — not a fitment issue, but worth being aware of during installation.