since no one else wants to help lol, I think you can swap a 325i AFM and swap the electronics out to get more air in and you might need bigger injectors. Xlibelle didnt you do this with a 7 series afm? How did that work out.
18s? sorry I will have to laugh at that too. You wither have show or go you cant really have both. Just like people with 4 subs and want to break 14 seconds, lol take the subs out and you will get 12s (sarcasm)
Anyways, do that, chip will help, I dont think exhausts work to well on an 18 because they lose so much backpressure you get no torque.
Get a ram air going, easiest way is to get some ducting from home depot and take a low beam out and run it right there, you WILL notice a good difference in power. If you dont believe me just clean your filter out and you will notice.
Horsepower TV Just did a thing about changing fluids out.
They took some ghetto stang and dynoed it. They got 200 at the wheels. Then they changed the tranny, diff, and engine oil for synthetic. They also added some coolant additive,
The car then dynoed 211 at the wheels