Mk7 GTI Intercooler Test

Mk7 GTI Intercooler Test
Mk7 GTI Intercooler Test

1.0 Background

1.1 Summary

This test project is being undertaken in support of a goal to equip my golf Mk7 GTI with the “best” Air to Air Intercooler.  The word best is in quotes since what is best is defined by goals that can be different based on individual owner prioritization of multiple factors.

1.2 Previous Test Results

  • Supplier testing is a source of partial results for some products.
  • Owner operating data is also available but subject to wide variations in collection and operating methods in addition to vehicle and recording equipment.
  • Flowbench testing and in use operating data has been recorded for a small number of products.

2.0 Purpose of Test

Determining what intercooler, or combination of intercoolers in the case of bi-coolers, available for the Mk7 GTI offers the best combination of cooling capability and low pressure drop is the objective of this test.

3.0 Systems under test

3.1 Intercooler

The Mk7 GTI utilizes an air-to-air intercooler that is located between the vehicle radiator and air conditioning condenser and is the subject of this test.  There are a number of aftermarket intercoolers that replace the stock GTI intercooler.  Another intercooler option is located in front of the air conditioning condenser.  Options for this intercooler function both independent of the stock intercooler, bypassing it entirely, and in parallel with the stock location intercooler, referred to as a bi-cooler.

3.2 Test Item

As of April 2, 2021 intercoolers that are to be considered are identified by vendor name and are as follows:

  • OEM Mk7 GTI
  • 1stRacingUK (eBay)
  • Majesty FMIC
  • Vibrant 12810 FMIC
  • Neuspeed FMIC
  • Treadstone TR8L FMIC
  • Treadstone TR8C FMIC
  • AMS
  • APR
  • CTS
  • do88
  • Forge
  • IE v1
  • IE v2
  • Mishimoto
  • Unitronic
  • Majesty stock location
  • Wagner

Other options:

  • Airtech
  • Burger
  • HG Motorsport
  • HPA
  • Leyo Motorsport
  • MTC
  • Racingline
  • Revo
  • Pro Alloy
  • PWR

3.3 Test Instrumentation

Temperature measurements will be made using the vehicle built-in sensors along with Resistance Temperature Detectors (RTD).  Pressure measurements will be made using the vehicle built-in sensors and a 3 Bar MAP sensor.  Airflow measurements will be made using a PTS flowbench and digital manometer.

4.0 Scope of Intercooler Test

4.1 Test Environment

Measurements of temperature with an intercooler installed on a GTI will be made on public roads in central Florida.  Bench tests measuring airflow and temperature will take place in a garage, also located in central Florida.

4.2 Test and Test Conditions

  • Loop drive – A predefined route that facilitates repeatability and exposes the intercooler to a range of different street operating speeds.
  • Third gear acceleration – Full throttle acceleration in third gear up to a minimum engine speed of 6000 RPM.
  • Bench cooling test – Test of the intercooler cooling performance outside of the vehicle.
  • Bench pressure drop test – Test of the intercooler pressure drop performance outside of the vehicle.

4.3 Test Criteria

4.3.1 Assessment Standards

Success / Failure criteria – Products will be evaluated for performance differences relative to other products.  There are no predetermined baseline values against which the products will be evaluated.  As data is recorded average values will serve as a quick check of success, performing better than average, and of failure, performing worse than average.

Charts will be the primary means for presenting relative performance data.

4.3.2 Completion Standards

Testing will end when the cooling and airflow data gathered is sufficient to support a conclusion about the best performing product of those that are available to be tested.  Product availability is expected to be a limitation to this test project.

4.4 Limitations to Scope

There are a number of operating conditions that an intercooler could be subjected to that will not be evaluated during this test.  Some examples are quarter mile drag strip full throttle acceleration, 60-130 miles per hour full throttle acceleration, road course, and autocross.

There are a number of aftermarket intercoolers available for the Mk7 GTI and it is expected that not all will be made available for testing.

5.0 Method of Intercooler Test

5.1 Test Methods and Procedures

Testing will consist of estimation analysis and performance analysis.

More details about the methods and procedures used will be provided on individual product test pages..

5.2 Support Requirements

Access to candidate intercoolers will be important to determining the range of performance available and average performance values.

6.0 Project Management

6.1 Supplies

All products tested and testing equipment are supplied by the test conductor with the following exceptions:

6.2 Reports

6.2.1 Product Test Results

Links to individual test results will be made here.

Stock GTI

1stRacing UK




Baun / Vibrant






Golf R


Integrated Engineering






Miscellaneous Comparisons

6.2.2 Test Result Summary

Summary charts will be presented here.

Note: All data points for each stock location IC are shown on this chart by the gray circles. The dark square is the sample average.

Stock Location IC Performance

Summary of flow bench airflow testing:

Note: Airflow is correlated with pressure drop, an important attribute of IC performance, but not the only consideration. Airflow is less correlated with cooling, another important attribute. Don’t rely only on airflow when considering these products, unless cooling is unimportant to you.

Mabotech IC Airflow Test
Stock Location IC Airflow Test
CTS FMIC Internal Air Flow Test
FMIC Internal Air Flow Test

Bench airflow versus operating pressure drop:

Bench vs Street Pressure Drop Correlation
Flow Bench Airflow vs Vehicle Operating Pressure Drop Correlation

CTS FMIC External Air Flow Test
External Air Flow Test

Pull series temperature delta trend.

  • Stock GI Dot Trend
  • Golf R
  • APR
  • AMS
  • ARM
  • do88
  • HPA
  • IE v1
  • IE v2
  • Mabotech Dot Trends
  • Racingline
  • Unitronic IC Dot Trends
  • Wagner Dot Trends
  • Neuspeed
  • Treadstone TR8C
  • Vibrant / Baun
  • IE v1 + Majesty
  • Stock GTI + Majesty
  • Stock GTI + ARM
  • AMS + Majesty
  • AMS / G-Plus

Temperature rise trends by intercooler type:

Intercooler Average Delta Trend
Intercooler Average Delta Trend

The chart above shows how the intercoolers I have tested compare on average during a third gear pull. There have been twelve (12) stock location ICs, three (3) front mounted ICs, and seven (7) bicooler pairs tested.

7.0 References

Link to reference information.