Water-to-Air Intercoolers

Does your intake temperature climb after just a few laps on a track day, or is there no room for a large front-mount cooler? A water-to-air intercooler cools the charge air via a coolant circuit and can be placed close to the engine. It is for you if you are building a turbo project with limited space or a high power target.

How a water-to-air intercooler works

The charge air from the turbo or supercharger passes through a compact core, where coolant absorbs the heat. The coolant is then pumped to a separate heat exchanger at the front of the car. The short air path typically means less volume between compressor and engine, which can give quicker response, while the system in turn requires a pump, hoses and extra coolant. If you are unsure about the type, you can compare with our other intercoolers.

How to choose the right cooler

Size alone does not determine performance. Weigh these factors together:

• Power target: The universal coolers from Mishimoto are available for e.g. 500, 1000 and 1500 hp, so you can match the core to your project.
• Connections: Choose between inlet and outlet on the same side or on opposite sides, depending on how the piping needs to run.
• Cooling capacity and pressure drop: The number of passes and the core design affect both how much heat is removed and how much boost pressure is lost.
• Space and cooling circuit: Measure up for the core, heat exchanger, pump and expansion tank.

Vehicle-specific solutions such as Mishimoto's intercooler for the BMW F8X M3/M4 or the system from APR for the Audi RS5 B9 2.9T are developed for a specific model. Always check fitment based on the part number.

Installation and maintenance

The cooling circuit must be bled thoroughly after installation, as air pockets can reduce cooling capacity and cause local overheating. Regularly check the coolant level, hoses and pump function, and change the coolant according to the manufacturer's instructions. Whether the modification requires inspection or approval depends on the product and the car, so check this for the specific part number.

Frequently asked questions

What is the difference between a water-to-air and an air-to-air intercooler?

An air-to-air intercooler cools the charge air directly with the airflow from driving, while a water-to-air model uses coolant that releases the heat in a separate heat exchanger. The water-to-air type typically takes up less space at the engine but requires a pump and an extra cooling circuit.

Why does cooling capacity drop after several hard pulls in a row?

The coolant can heat up faster than the heat exchanger can shed the heat, especially during track driving. How long the system holds its temperature depends on coolant volume, pump capacity and the size and placement of the heat exchanger.

What does inlet and outlet on the same side or opposite sides mean?

It indicates whether the charge air enters and exits on the same side of the core or on opposite sides. The choice depends on how the piping from turbo to intake can best be routed in your engine bay.