BMW F82 M4 Auxiliary Radiator Upgrade DIY (2015-2021 BMW F80 M3, F83 M4, F87 M2)

Air-to-water intercoolers have become somewhat of an industry standard for performance vehicles. Regardless of the reasoning for use, it utilizes a separate radiator to cool the coolant within its dedicated cooling circuit. It's a system perfectly paired with the stock power output. However, the auxiliary radiator will be overmatched once the boost is turned up and the intake air temps are higher. If that's your current issue or one you know you'll eventually have, consider upgrading to an aftermarket radiator.

Increasing the cooling efficiency of the auxiliary radiator will only benefit the charge air temperatures. The more heat can be pulled from the coolant, the more heat will be pulled from the intake air. Colder intake air means a denser air/fuel mixture in the combustion chamber, resulting in more power. It's also a perfect pairing for a larger intercooler, which will carry more coolant.

In this video, Mike Hidalgo, FCP Euro's Professional DIYer, replaces and upgrades the auxiliary radiator on a BMW F82 M4.