I saw a consistent 3-4 MPH increase in trap speeds just after installing the KKM I had. Similar weather, similar altitude, two weeks apart. I only gained about 0.1 seconds in ET.
The fact that I was running traps on a 75 degree day with the KKM that were only rivaled on a 45 degree night with the stock airbox at a better track and K&N drop in says there is a measurable gain with an open air filter, almost completely at top end/high RPMs.
