Wagner Tuning BMW Z4 G29/Toyota Supra GR B58 Chargecooler Radiator Kit

Wagner Tuning Chargecooler Radiator Kit – BMW Z4 G29 & Toyota Supra GR (B48/B58)

The BMW Z4 G29 and Toyota Supra GR share the same B48 and B58 engine platforms, and both rely on an indirect intercooling system to cool the intake charge air. Instead of using outside air directly (as a traditional front-mounted intercooler would), these engines pass the intake charge through a water-to-air chargecooler. A dedicated coolant circuit carries heat away from this unit, with a small radiator at the front of the car cooling the fluid before it cycles back round.

The principle is simple: the cooler the fluid in that circuit stays, the better the system can reduce intake air temperatures before the charge enters the engine. Lower intake temperatures mean denser air, more consistent power, and less risk of timing being pulled back by the ECU during hard driving.

Why Upgrade the Chargecooler Radiator?

The factory chargecooler radiator copes well enough in everyday driving, but it has its limits. Under sustained spirited driving, on track, with a tuned ECU, or simply during warmer weather, the small OEM unit can struggle to keep fluid temperatures in check. Once the coolant heat soaks, charge air temperatures climb and performance tails off.

Wagner Tuning’s upgrade addresses this directly with a much larger, more capable radiator designed specifically for the G29 Z4 and GR Supra chassis.

What Makes the Wagner Radiator Different

Wagner Tuning have developed an all-new Competition racing core for this radiator. Compared to the OEM unit, coolant volume increases by 117%, from 7.70 litres to 16.70 litres. The larger volume of fluid in the system takes considerably longer to heat soak, which keeps charge air temperatures lower for longer during hard use.

Despite the much larger core, Wagner have carefully balanced the internal and external cooling surface areas. This is important because the chargecooler radiator sits in front of the main engine radiator. If airflow is overly restricted, engine coolant temperatures rise instead, so the design has been optimised to allow sufficient airflow to the components behind it.

Each radiator also features a heat-conductive anti-corrosion coating applied to the core. This helps maintain long-term cooling efficiency and protects against deterioration over time.

Dimensions and Specification Comparison

The Wagner unit is notably thicker (68 mm versus 27 mm) to accommodate the larger core volume, while being slightly more compact in its face dimensions. This is a deliberate design choice to balance cooling capacity with fitment and airflow to surrounding components.

Key Benefits

• 117% increase in coolant volume for greater thermal capacity
• More stable charge air temperatures during sustained or hard driving
• Optimised core design to preserve airflow to the main engine radiator
• Heat-conductive anti-corrosion coating for long-term durability
• Direct replacement for the OEM chargecooler radiator

Installation

Fitment has been designed to be as straightforward as possible, with Wagner describing the installation as near plug-and-play. Full installation instructions are included with the kit. As with any cooling system work, the chargecooler circuit must be properly bled of air after installation to ensure correct fluid flow and prevent hot spots. If you are not confident with cooling system