Wagner Tuning BMW M3/M4 F80/82/83 Radiator Kit

Wagner Tuning Radiator Kit – BMW M3 / M4 (F80 / F82 / F83)

The BMW M3 and M4 (F80, F82, F83) are powered by the 3.0-litre S55B30 twin-turbocharged engine, a capable unit that generates serious heat under hard driving. Keeping coolant temperatures in check is essential for maintaining consistent performance, particularly on track or during spirited road use. This Wagner Tuning Radiator Kit is designed to do exactly that.

Unlike a conventional turbocharged setup, the S55 uses an indirect charge air cooling circuit. This means the compressed intake air from the turbos is cooled using a separate low-temperature water circuit, rather than directly through an air-to-air intercooler. Keeping that coolant circuit cool is critical; if it heats up, charge air temperatures rise and power drops. This Wagner kit replaces both the front and side low-temperature radiators with significantly larger, higher-capacity units to address this directly.

Why Upgrade the Radiators?

The factory radiators are adequate for standard use, but under sustained high-load conditions such as track days, dyno tuning, or aggressive road driving, the low-temperature cooling circuit can struggle. As coolant temperatures climb, the engine management system (ECU) pulls back boost and timing to protect the engine, resulting in reduced power output. This is commonly known as heat soak. Fitting larger, more efficient radiators keeps the system cooler for longer, helping the engine deliver consistent performance rather than fading after a few hard runs.

Size and Capacity Improvements

The increase in size over the standard radiators is substantial. The front unit grows from 4.5 litres to 8.5 litres of coolant volume, an 89% increase, while the surface area available for heat transfer increases by over 46%. The side unit grows from 1.65 litres to 3.2 litres, a 94% increase in volume. These are not minor tweaks; they represent a meaningful step up in the system’s ability to shed heat and maintain stable temperatures.

What’s Included

• 1x front water cooler (low-temperature circuit)
• 1x side water cooler (low-temperature circuit)
• 1x carbon air duct for the side water cooler
• Mounting hardware
• Installation instructions

Quality and Construction

Wagner Tuning is a well-established German manufacturer known for its high-quality cooling and charge air components. The radiators are constructed from high-grade aluminium with optimised internal flow paths and dense fin arrangements to maximise heat dissipation without restricting coolant flow. The included carbon air duct directs cool air more effectively onto the side radiator, further improving its efficiency.

Who Is This Kit For?

If you regularly drive your M3 or M4 hard, attend track days, or have tuned the S55 engine for additional power, this kit is a sensible upgrade. Higher boost levels and longer periods at full load place greater demand on the cooling system, and the standard radiators were not designed with that level of use in mind. Even on standard cars, drivers in warmer climates or those who simply want extra thermal headroom will benefit.

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