Er... I was chasing down an RSX on the way from school-> freeway... and i noticed when I'd shift my motor would be screaming but... the car, for the most part, would be sitting relatively still... It's supposed to be somewhat of a linear equation...

The only difference = I have new shoes... theyre a little taller than I'm used to, but thats still no excuse for the "push pedal, car goes nowhere" thing...

I'm only doing 5.5psi, its a new stock clutch, trans has 30k on it... Should have just upgraded when I replaced transmission but I didnt care/didnt think of it...

Spec Stage 3? I wont be boosting more than 5psi unless I decide to keep the car...

drive home from work... my shoes are definitely having a large effect on the way i'm shifting... plus for some reason I'm shifting really early, which gives the sensation of slippage... ugh i dont even know

Your foot is going to have to pick up a little higher now because you have more shoe between your foot and the pedal. Otherwise your clutch wont fully engage. This is why your engine is reving and your clutch is slipping.