Wagner Tuning Audi RS4 B9/RS5 F5 Radiator Kit (OEM IC)

Wagner Tuning Audi RS4 B9 / RS5 F5 Radiator Kit (OEM Intercooler Variant)

The Audi RS4 B9 and RS5 F5 share a 2.9-litre twin-turbocharged V6 that relies on an indirect charge air cooling system. Instead of using outside air to cool the intake charge directly (as a traditional front-mounted intercooler would), a separate water circuit carries heat away from the intake air before it enters the engine. The cooler that water stays, the more effective the whole system becomes – and that is exactly what this Wagner Tuning upgrade addresses.

This kit replaces the factory water cooler (sometimes called a chargecooler radiator) with a higher-capacity competition unit, increasing total radiator volume by 55% over the original. More coolant volume and a more efficient core mean intake temperatures stay lower for longer, helping the engine hold its power under sustained hard driving on track or spirited road use.

How It Works and Why It Matters

On the standard setup, the factory water cooler can become a bottleneck when the engine is working hard. As the coolant in the charge air circuit heats up, it loses its ability to absorb heat from the intake charge. The result is rising intake temperatures and the ECU (the engine’s control unit) pulling timing or boost back to protect the engine – which you feel as a drop in performance.

The Wagner Tuning core is designed to dissipate heat more efficiently and keep coolant temperatures lower and more consistent throughout the cooling circuit. The redesigned core also balances internal and external cooling surface area, so heat transfer is maximised without restricting airflow to the main engine radiator sitting behind it. A thermally conductive anti-corrosion coating protects the core over the long term while helping it maintain cooling performance over time.

Key Benefits

• 55% greater coolant volume than the OEM water cooler
• Lower, more stable intake temperatures under sustained load
• Helps reduce power loss caused by heat soak on track
• Direct fit – no modifications to the vehicle required
• Anti-corrosion coating for long-term durability

Fitment

This kit is designed for the Audi RS4 B9 (Avant) and RS5 F5 fitted with the 2.9 TFSI V6 engine. This is the OEM intercooler variant, intended for vehicles retaining the standard intercooler. Please use the vehicle lookup tool or check the Vehicle Fitment tab to confirm compatibility with your specific car.

Installation

The kit is engineered as a direct replacement for the original unit, fitting in the same location without bodywork or bracket modifications. Wagner Tuning supply detailed installation instructions. The coolant circuit will need to be drained and refilled as part of the job, but no specialist fabrication is required.

Important: After installation, the cooling system must be properly bled (purged of air) and refilled with the correct coolant mixture before the engine is run. Follow the supplied instructions carefully to avoid air locks, which can cause overheating and serious engine damage.

Technical Specifications

For owners looking to get the most from their RS4 or RS5 – particularly those who use their car on track or in warmer conditions – this radiator kit is a sensible, well-engineered upgrade that targets one of the platform’s known weak points without altering the rest of the cooling system.