My understanding is that it's relieving of the pressure within the wheel well. I can't remember which issue it was, but there was a multi-part Aerobytes feature on the ADR3 in Racecar Engineering and they did try various louvre positions. The forward position was of benefit - the standard vents were fitted aft of the wheel centre line. This is the position I chose on my car:MadMatt wrote:The positioning of the louvers is also very important. People tend to fit them as far up front as they can in a longitudinal plane, but I cannot really see any relevant research proving that concept. I believe it has to do with what I explained, the high pressure in front of the tyre, as there is indeed a low pressure area behind the wheel so why would you want to exhaust it on top of the car, hence the louvers located at the front of the wheel well.
