In the first post you asked

How close is the heat gun output to the incoming air in terms of temperature and density?

Your question is confusing, what incoming air are you referring to? I'm going to guess that you're asking how close the temperature and density of the air output from the hair dryer was to what would be found entering the IC on the car. The answer is, it depends. The hair dryer puts out a reasonably consistent volume and temperature of air, two desirable qualities in a test that looks at performance under steady state conditions. The temperature and density of the intake air on the car fluctuates with a variety of factors, such as vehicle speed, mass airflow, boost, ambient temperatures, atmospheric pressure, relative humidity, amount of time the car has been running. To reproduce the conditions as closely on the car as could be done with the hair dryer was not possible.

How fast does the shop fan blow? Not to mention the lack of "shrouds". It didn't matter how fast the fan blew the air over the IC's, since the test was done for both IC's at a single speed. Your question seems to suggest that the test should have been trying to simulate road conditions. But that is problematic since the vehicle operates over a large speed range and to try and simulate those conditions would have required much different test equipment and multiple runs. Using the shrouds might have affected the results, or might not have. The test was not meant to be exhaustive.

I appreciate the effort, but this is FAR from proper evaluation - all you can say is that the IPPs cool better than the stockers under these conditions. I agree that the only hard conclusion you can draw is the relative performance for the tested conditions. But, you are mistaken when you say it is "far from proper evaluation". It is in fact quite proper considering the resources available for testing and the stated goals. It was not an exhaustive study; time, resources, and motivation prevented that type of testing from being performed.

Bolt both on your car then compare. It is absurd to think the relative performance of just the intercoolers will be better measured by installing them on a vehicle where a multitude of other variables impact the outcome.

He doesn't have control over 2 of the most important variables - the incoming air and the air across the IC. This is a curious statement coming from you. How would you know whether or not the test system provided consistent input to the test articles unless you were present taking measurements? There is no reason to believe that the output from the hair dryer or the airflow produced by the fan fluctuated significantly enough between test runs to have meaningfully impacted the overall results.

Just because the variables are the same between the tests doesn't mean that this is a remotely accurate model. The purpose of the test was not to model the intake components and variables that interface with the IC's. It was to evaluate the relative capacity for each intercooler to dissipate heat produced by a steady source, without the benefit of forced convection, and then with the benefit of forced convection from a steady cooling source.

Under the stated test conditions we can draw some conclusions about the relative performance of these two intercoolers. Any time a test is performed the goal is to explain the factors that caused the results. It appears very likely that in this test the results are due to the relative capacities of each intercooler to transfer heat from the intercooler to the surrounding air. It is unlikely that the test procedures or apparatus meaningfully impacted the results obtained. If you read the test summary with the idea that it was an attempt to accurately model the intake system on the S4 and to evaluate the intercoolers over the entire range of possible operating conditions you were mistaken in your understanding of the goal of the test. If you believe something other than the IC performance caused the reults obtained I'd like to hear what you think that might be.

National Motorists Association