I will say this though.... I have a d series in my race hatch at the moment while I save for more K series parts....

my cx weighs about 1900lbs, d16y7 with z6 manifold and full exhaust. It's suprisingly quick. It feels similar to my 92 hatch with b18b1.

Sooo.... what I'm getting at is if you want to be faster without turbo or swapping loose some weight off of your car, because that will help just as much as all those expensive mods you are talking about