Mosselman carried out a very comprehensive intercooler comparision test on an N54 BMW 135i with 4 different front mount intercoolers to see which was best.
You can download the full test here
As is the nature of the performance car parts industry, there is always a push to replace factory parts with so called performance parts. Unfortunately the hard figures which back up the improvements are usually lacking or the figures presented are not as scientific as you would hope. ie is it possible to replicate the test from the information given by the manufacturer of the performance part?
In most cases it is not possible to replicate the tests because not enough information is given, which makes it hard/impossible to compare the results provided by the manufacturer of the part.
So this intercooler comparison test on a BMW 135i is a refreshing change. Comprehensive data is given on the environmental conditions and also how exactly the data was recorded.
Temperature controlled dyno room with adjustable fans, pressure drop across the intercoolers and temperature difference across the intercoolers to highlight a few of the key things measured.
Intercoolers are one of the most popular upgrades for turbo cars and the prices between the cheapest products and the most expensive is massive. It is nice to see a test to see what exactly you get for the money.
To summarise this intercooler comparison test.
The stock BMW intercooler came out on top. While its performance was not the best of the test, when you take into consideration its price (ie free with the car) its weight and its performance, it was an easy win for the BMW part.
With emissions targets becoming more and more important, it is becoming harder and harder to get easy wins with parts like intercoolers. Instead of reinventing the wheel and all of the costs that go with it, I believe the trend in the future will be maximising the efficiency and performance of the parts fitted to the car from the manufacturer.
The moral of the story
If a manufacturer of a part does not give you the data you need to replicate their test, then the figures should be treated with caution.
Also bear in mind that a part manufacturer will always want to focus on the figures that show the biggest differences, even if these figures are not actually relevant to what you are trying to achieve. For example flow rates. It is great that one product will flow more air than another but do the airflow rates used in the tests figures have anything to do with reality
Will you actually ever see so much airflow through your engine?
And what is the effect on the engine performance?
Fundamentally we are fitting an intercooler to get more power without adding any extra stress on the engine, and preferably reducing heat stress on the engine. Does the product improve these figures and do you have the information to replicate the results yourself?
At the end of the day, on the road acceleration results carried out in the same atmospheric conditions are the first thing we need to look at. If we don’t have these number and/or we don’t have the data to test the validity of the manufacturer figures, again, treat the marketing material with caution.
