Composite pressure drop

The chart below shows an approximation for how the stock B5 S4 intake system compares against an aftermarket alternative.  The various system components were tested separately, so the composite results shown below do not accurately depict how all of the parts would measure if operating on the automobile.

Additionally, when on the vehicle the operating pressure would in many cases be much higher, which would cause the pressure losses to be greater.  Still, the chart gives some indication to the scale of improvement that can be obtained through the use of aftermarket or alternative parts, at the tested airflow of 500 CFM.

The legend shows the different configuration tested.  To the left of the slash ( / ) is the stock configuration and to the right is the modified and/or aftermarket configuration.

Composite pressure loss chart

IC Info Summary

The following information is a summary of data I have personally recorded as well as information I have obtained by viewing the results provided by others.

This information should not be taken as ground truth, there can be variability in results dependent upon how a car is operated, what environment it is evaluated in, and how the information is collected.  The point of presenting this data is to make available to others the information that I use.

IC Summary DataIn the following scatterplot, products for which I do not have IAT data are shown along the vertical axis at an IAT Rise value of zero.