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.
Whatsmore 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.
Let's take a look at the stock cooler...
The Stock Cooler:
1-row 26mm core
7mm fin height
The stock cooler uses a single row, 26 mm core and is of a single pass design. This is a very thin core for this that does not make use of the available space efficiently which contributes to the cooling issues. After months of development, we have developed a solution which maximises the efficiency and of the space available whilst maintaining all of the factory mounting locations, hose locations etc for a direct replacement part, our specification is below...
CSF's All-Aluminium Triple Pass Water Radiator
2-row 42mm B-tube core
6.5mm fin height
The CSF All-Aluminum Triple Pass Water Radiator utilises a 2-row 42mm core. Utilising all of the space between the condenser and radiator the core depth has been maximised and compatibility confirmed with large aftermarket intercoolers such as IE. The B-tube design maximises the tube efficiency in all areas, this tube design is stronger than 0-tubes less material can be used for a lighter more efficient heat transfer whilst surface area inside the tube is increased by 15% over 0-tubes.
The Triple Pass design means coolant passes across the core three times before it exits maximising the time the radiator has to exchange heat for the coolest outlet temperature. Finally, the 6.5mm fin height has been wind tunnel optimised in CSF's in-house wind tunnel, leaving no stone unturned in the pursuit of the ultimate MQB Water Radiator solution.
TESTING: CSF All-Aluminum Triple Pass Water Radiator & Quadruple Pass DSG Cooler on 500HP Track MK7R
The customer reported that engine water temperatures when logged properly were showing regularly in the 110c and even as high as 130c on track. As well as this, engine oil temperatures were a huge concern, rising to 130c within 3 fast laps and then rising uncontrollably through 130cs to over140c, the customer then had to drive between 4500RPM-5500RPM to maintain a "safe" oil and water temperature.
With the CSF's cooling upgrade this is no longer the case, testing has shown that engine water temperature does not go above 100.5c. The engines oil temperature is also running under 125c in this test which the customer reported was a drop in as much as 10c-15c. Previously, the engine oil temperature would rise to 130c within 2-3 fast laps and then rise uncontrollably to well above 130c - 140c plus, to keep under 130c.
Conclusion: CSF's MQB Cooling Upgrade drops both engine water and engine oil temperatures consistently.
TESTING: CSF All-Aluminum Triple Pass Water Radiator, Quadruple Pass DSG Cooler & Quadruple Pass Auxilary Engine Water Radiator on 500HP Track MK7R
With the success of the above test the customer then wanted to add the Quadruple Pass Auxilary Engine Water Radiator to their car. In 10c higher ambient than the above testing and a higher load circuit (GoodWood) the customer experienced the same 100.5c peak engine water temperatures and engine oil temperatures well under the 130c level.
Conclusion: CSF's MQB Cooling Upgrade provides a large increase in cooling power to the factory water cooling circuit, enough to keep engine water temperatures well within ideal operating conditions and has a benefit for engine oil temperatures too.