Recently I tested the car without a filter at all and the behavier is even worse. More g/s, richer AFR @ same manifold pressure.
Maybe I should post this in another category?
SubiCarLous wrote:
Hello all,
I use the CarBerry rom in my STi for a long time with about 380hp. Recently I replaced the air filter with an aftermarket one (rest intake is OEM) and gained about 20 g/s at the top and I though wow, only with an air filter, was it really so much restriction? I also measured the acceleration multiply times with GPS 4th gear and realised that the car is now on avarage a little bit slower then before. After more research I found out that the AFR dropped about 0.3-0.4 to the rich side only at high boost. Now I'm really confused. The boost pressure is always the same but the AFR changes a lot between the two filters and according the fuel table axis it should not change at all. Even if the filter would case turbulences and MAF readings would change, the AFR should not change at all, right?!
I tested different boost levels and it's always the same problem. At 1 bar about 0.3-0.4 AFR drop and at 1.6 bar 0.3-0.4 AFR drop. How can this make sense?
Can someone please put me on the right track what the problem could be? I am really stuck right now.
