hi guys, I have a z4 2.5si which I've been modding like crazy. now it looks almost like I want it too so I'm moving to the power department. I put a k & n filter and some z4m cans and mid section exhaust and it seems the car got a little more power but now I'm considering getting headers but don't know if it would allow too much flow which means less backpressure which in turn may translate into hp losses. I don't care too much for the sound or the emissions as in my country they are not too picky about that, I just want to get as much power as I can from my car. btw I dynoed my car in 184 hp in a local heartbreaker dyno dynamics which should be decent given that I got it with 85 aki pump gas which is awful. please guys help a fellow in his quest for power and share your thoughts 
