Wagner Tuning BMW M3/M4 F80/82/83 Side Mount Radiator

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

The BMW M3 and M4 (F80, F82, F83) are powered by the 3.0-litre twin-turbocharged S55 engine, which uses an indirect charge air cooling system. In simple terms, a water-to-air intercooler setup uses a dedicated low-temperature coolant circuit to pull heat out of the compressed (charged) air before it enters the engine. The cooler that coolant stays, the denser the air entering the engine, and the more consistent the power delivery, especially when the car is being driven hard.

This Wagner Tuning side mount radiator is a direct replacement for the factory side-mounted low-temperature radiator. It significantly increases cooling capacity, helping keep coolant temperatures in the charge air circuit under control during sustained or spirited driving.

Why Upgrade the Side Mount Radiator?

The factory side radiator is a well-known weak point in the S55 cooling system. Under sustained load – track use, long pulls, or hot ambient temperatures – the standard unit can struggle to keep low-temperature coolant in check. Once charge air temperatures climb, the ECU (engine control unit) will pull timing and reduce boost to protect the engine, which means a noticeable drop in performance.

This upgrade tackles that limitation directly by moving more heat out of the coolant circuit, helping the engine maintain its target power for longer.

• Core volume increased by 94% over OEM, from 1.65 litres to 3.2 litres
• Core surface area increased by nearly 15%
• High-performance competition mesh core design for efficient heat transfer without restricting airflow to nearby components
• Thermally conductive anti-corrosion coating for long-term durability
• Includes a dedicated carbon air duct to channel air through the upgraded core

The carbon air duct is a useful inclusion. It directs incoming air through the larger core rather than allowing it to spill around the sides, so the extra surface area is actually put to work.

What’s Included

• 1x side mount water cooler (low-temperature circuit)
• 1x carbon air duct for the side water cooler
• 1x mounting hardware kit
• 1x installation instructions

Fitment

This radiator is designed for BMW M3 and M4 models on the F80, F82, and F83 platforms fitted with the S55 engine. Please use the vehicle lookup tool on this page or check the Vehicle Fitment tab to confirm compatibility with your specific model and build date before ordering.

Installation Notes

The radiator is designed as a near plug-and-play replacement, using the supplied hardware and Wagner Tuning’s instructions. As this is part of the coolant system, the circuit will need to be drained and properly bled after fitment. If you are not confident working with cooling systems, we recommend having it installed by a competent mechanic or performance workshop.

Technical Specifications

For owners pushing their M3 or M4 on track, at driving events, or simply wanting more consistent performance in warmer conditions, this side mount radiator addresses one of the platform’s known cooling limitations with a quality, well-engineered upgrade.