ok so i have the 4" FWI setup in my car and i was driving in the rain and everytime i gave full throttle it would studder.....found out my filter was sucking water in from right behind the headlight.....no hydro lock 
but i noticed that on a 2nd gear pull it still vibrates a lil and i feel a power loss? is it still working out the moisture like the water is killing my octane levels? also is that vibration i feel at 5000 rpm knock?
but i noticed that on a 2nd gear pull it still vibrates a lil and i feel a power loss? is it still working out the moisture like the water is killing my octane levels? also is that vibration i feel at 5000 rpm knock?