The cooling ineffectiveness of the DSG Cooler can be explained after examining the stock cooling system design. 

The factory coolant routes out of the engine block, into a Y-piece where it splits into the engine water radiator and then into the DSG cooler. This DSG Cooler is surprisingly small and does not have the size or efficiency to exchange heat before it exits the cooler and routes to the DSG oil/water heat exchanger.

If the engine coolant is hot and the DSG oil is hot, which is the case when driving cars with a higher output than stock, spirited or track use, this hot coolant now has little to no cooling effect on the DSG oil and DSG temperatures begin to rise…

With a high oil temperature, the DSG is at risk of becoming damaged. To help prevent damage the DSG will begin to lower the torque, increase shift times and in extreme circumstances gears can be lost. In the worst cases, costly damage to the gearbox can be caused. 

After extensive analysis and development, CSF has created a Quadruple Pass DSG Cooler gives an increased cooling performance over the stock item in a number of areas. 

Stock Cooler: 

• 26mm 1-row core

CSF Quadruple Pass DSG Cooler

• 2-row 42mm Core with CSF B-Tube Technology
• Quadruple Pass Design
• Removable Rock Guard 
• Flow Area Increase = 42%
• Heat Rejection Increase = 36%
• Fits both Right Side (DSG) and Left Side (Auxiliary Engine Water)

The CSF Quadruple Pass DSG Cooler uses a 2-row 42mm core, this utilises all of the available space. 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 Quadruple Pass design means coolant passes across the core four times before it exits maximising the time the radiator has to exchange heat for the coolest outlet temperature. 

This unique design results in a flow area increase of 42% and a heat rejection increase of 36%. Helping to keep DSG temperatures consistently cooler for longer. The radiator also comes complete with a removable rock guard for improved longevity against rock hits/debris.

TESTING: CSF All-Aluminium Triple Pass Water Radiator & Quadruple Pass DSG Cooler on 500HP Track MK7R

The customer reported that the DSG gearbox in his Golf R would begin to feel sluggish, shifting slowly and even entering a reduced power mode when pushing hard.  Once the CSF Quadruple Pass DSG cooler was fitted this problem was eliminated, testing has shown that the DSG oil temperature now rises and falls with the engine coolant temperature which in this test did not go above 100.5c. 

Conclusion:  The CSF Quadruple Pass DSG Cooler keeps DSG temps well within ideal operating conditions. 

Fits: 8V S3, 8S TT (2.0TSi), MK7 Golf R, 5F Leon Cupra.