The APR Intercooler System is an OEM-location upgrade that dramatically reduces intake air temperature (IAT), minimizes heat soak, and provides increased performance! The system is a direct bolt-on upgrade that requires no trimming and is recommended at every performance stage.

DESIGN

APR pioneered the OEM-location direct-replacement intercooler system in 2006. Unfortunately, to the untrained eye, many intercooler designs appear the same. However, several key metrics greatly determine the system's effectiveness and overall performance. Alloy selection, end tank design, construction type, fin style, fin density and overall core dimensions must be analyzed and balanced accordingly to deliver class-leading performance. While the OEM’s goal is to create a lightweight, easy-to-manufacture, and inexpensive-to-produce, cross-platform design capable of supporting factory power levels, APR’s intercooler must support more than double the factory output. Achieving this goal took a multi-step approach focused on intercooler core selection, end tank design, and install location.

The APR Intercooler core is a large bar-and-plate design featuring densely packed staggered and louvered fins. This design offers exceptional cooling while balancing pressure loss across the core and maintaining critical airflow to the components behind the intercooler system. The core size was appropriately matched to the platform, minimizing pressure drop while leaving adequate space for appropriately designed end tanks. To APR’s mechanical engineering experts, the design represented the ultimate in performance, far exceeding the capabilities of the factory intercooler. To the driver, the result is simple: Repeatable performance, even in the most demanding of situations!

INTERCOOLER END TANK DESIGN

To fully utilize the massive core, APR’s mechanical engineers designed cast aluminum end tanks organically shaped for proper airflow distribution across the entire core. By correctly sizing the intercooler core, end tank design was not sacrificed. The one-piece end tanks are CNC machined to provide a slip-resistant mounting surface for hoses, precise integrated mounting surfaces, and perfectly flat connecting surfaces used for TIG welding the tanks to the core. Through proper alignment in welding jigs, each unit is assembled to tight tolerances for a precise and accurate fit.

TESTING

Internally, APR conducted many tests while choosing the appropriate intercooler core and end tank design. Thermocouples were placed at the top and bottom of the core to measure cooling effectiveness and cooling distribution across the unit. Pressure transducers were placed at the inlet and outlet of the intercooler to determine pressure loss across the various units. With this information, APR’s engineers specified the appropriate intercooler core type, dimensions, and cooling fin density. They made the design changes to the end tanks to ensure full utilization of the entire core. The end result was the development of a much more effective cooling system compared to the factory GTI and golf R intercooler systems. Effectiveness is measured as (Intercooler Inlet Temp – Intercooler Outlet Temp) / Intercooler Inlet Temp. The APR Intercooler system’s effectiveness under the most demanding situations was between 82-83%, while the factory GTI (Similar to Tiguan/Q3) struggled at 60% and the factory Golf R (Similar to Arteon) at 65%.

MK7 GTI 2.0T INTERCOOLER TESTING (SIMILAR TO TIGUAN/Q3)

Back-to-back stress testing on the dyno helped to further prove APR’s intercooler upgrade's effectiveness compared to the factory unit. Tests were first conducted with an APR Stage 2 MK7 GTI using the factory intercooler, then the slightly upgraded Golf R intercooler, and finally, APR’s Intercooler system. Each dyno pull lasted 12 seconds, with 5 seconds of dwell between runs. Raw sensor data was collected using APR’s ECU Explorer high-resolution data logging system. The tests quickly proved the long sought-after OEM “upgraded” cooler (factory Golf R intercooler) showed minimal improvement over the standard GTI unit. However, the APR intercooler saw a dramatic difference that positively impacted performance. The factory GTI and Golf R intercoolers saw a starting IAT of 43 °C and 42 °C which climbed to as high as 71 °C and 66 °C, respectively, by the end of only the first pull.

In contrast, the APR intercooler system saw IATs drop to 40 °C! The APR system effectively rejected heat soak and, by the end of the sixth run, saw a final IAT of 49 °C. In contrast, the GTI and Golf R intercoolers struggled to keep up, resulting in a final performance-robbing IAT of 84 °C and 82 °C. This translated to a final gain of 21 WHP over the GTI intercooler and 18 WHP over the Golf R Intercooler!