The Integrated Engineering V2 intercooler replaces the V1 for the Mk7 GTI / Golf R. Bench testing has been performed to evaluate pressure drop and cooling efficiency, now with the V2 intercooler installed on my GTI street operating performance data can be measured.
Data is recorded continuously during a drive that includes several periods of full throttle acceleration. The acceleration takes place in third gear, starting around 2,500 RPM and continuing until around 6,500 RPM. Air temperatures of interest are the outside air, at the turbocharger outlet, the intercooler outlet, and the intake manifold. Pressures of interest are of the air at the compressor outlet and the intake manifold.
An overview of all temperature readings along with boost pressure and vehicle speed for V2 are shown on the next chart:
The next charts focus in on the period of time during the drive when the 3rd gear pulls were conducted. Noted on the chart is the IAT above ambient temperature at 6,000 RPM.
Note: The steady rise of IAT delta during successive pulls is evidence of heat soaking.
The next chart shows Version 1 intercooler data under similar (but not exactly the same) conditions:
Pulling the IAT rise data for each of these intercoolers to compare requires eliminating some of the data points collected using V2 to make a fair comparison. The V2 was subjected to a higher number of pulls in series which the data shows leads to a higher outlet air temperature. Of a total of twelve observations three were discarded to produce a comparison under more similar conditions. The results of a t-test performed on the data indicates there is not sufficient evidence to believe the V1 and V2 intercoolers perform significantly differently on this test. Temperature rise data (degF over ambient) from this comparison is contained in the table:
Measure of the pressure difference between the turbocharger compressor outlet and the intake manifold (pressure drop in psi) is shown on the next chart. V1 is blue and V2 is red.
Bench airflow and operating pressure drop for all tested intercoolers is shown on the next chart:
Overall intercooler standings based on flowbench airflow and 3rd gear temperature rise is contained in the next chart:
Overall the difference in performance between the V1 and V2 is not large.
The V2 has a decent increase in airflow over V1 that translates to about a 1.2 psi maximum difference in pressure drop in the tested operating conditions.
The V1 has a slight edge in the street cooling numbers, but they are close enough that the conditions come into play.
Guessing as to why the V1 seems to cool slightly better; 1) it could be the conditions while recording the data. The recovery time between pulls was not controlled down to seconds. 2) It may relate to the small advantage the V1 showed on the bench cooling efficiency test. V1 seems to be a little more efficient at offloading heat from the core.
The performance edge goes to the V2, but the additional half an inch of core depth is not inconsequential in terms of the affect on engine compartment real estate.
Note: Conditions when testing these intercoolers can significantly affect the results. Time under load is a significant factor and this test subjected the intercoolers to 3-5 seconds of continuous load, time enough to accelerate from 25-30 mph up to ~90 mph.