Never mind guys. I came to my own conclusions...
The stock SVT airbox with a clean stock ford filter works better than a KKM. The KKM may produce a better number on the dyno but after a few minutes when the intake is hot, then the stock box will outperform the KKM or any other open air filter that is located under the hood.
Furthermore looking at the stock filter, I suspect that the bullet shaped nose on the end of it will smooth out the air going to the filter so the velocity of air may be higher. True that the stock opening is small, but the velocity of air through that would probably be better than some other filter that does not have that little thing on the end of of it. Speculation but it looks like it would make sense.
Anyway I believe that I may have lost about 5% of my top end compared to the KKM when both are cold but I have gained about 5% more top end when warm and probably what feels like 10% more torque when hot. I would kill my car the way it was before. The fault is not the KKM but the lack of cold air.
For myself, I think I'm going to stick to the paper filter and just buy a clean one every month. The paper filters tend to filter smaller particles than a clean KKM or K&N type filter. There is a chance that very small particles could get into the engine which over the long haul may be bad. True that when the KKM gets dirtier, then it would filter smaller particles but thats when most people would clean it and put it in again. Oh well...
I'm sure many will not agree with what I concluded but I feel that SVT engineers probably knew what they were doing with that airbox.
