With the MQB platform able to generate huge amounts of power, with an output increase of almost 30% achievable with intakes, exhausts, intercooler and software an often overlooked area for improvement is the factory engine water cooling system.
With such a substantial increase in output easily achievable it's easy to understand why the factory water radiator can struggle to exchange the heat from the engine and now exhaust gas heat from the integrated engine head exhaust manifold. It's not uncommon for these engines, whilst showing 90c on the coolant dial to actually be running in excess of 110c up to 130c during track driving when properly logged.
Whats more is that during spirited driving, whilst the engine water coolant temp becomes high so does the engine oil. It's not uncommon for engine oil temperatures to spike to over 130c-145c during spirited driving and struggles to reduce without substantial time spent cooling the car down. This is due to there being no factory engine oil cooler, so the factory water radiator has a lot of work to do.