Where's the beef?

I had the following parts installed on my 2K Maxima:

Stillen Y-pipe
Stillen Hi-Flow intake
Stillen FSTB
Stillen RSB
Unorthodox Underdrive Pulley

To tell the truth, I'm not feeling ANYTHING from the Y-pipe, intake, or the pulley. The handling is MUCH better with the RSB and the FSTB, but I'm just not feeling the kick that I thought I would be getting...is it just me or is a 12-20HP gain not that significant? I think I should have just gotten the super : ) ...I'm jealous of my friend's new Porsche 911...that thing is a bad muther.

While I have your attention : ) , anyone know what type of wiring harness the 5th Gen.'s have? Either ground switched or non ground switched systems. I'm thinking of getting the PIAA 80/80 Platinums and will need a new wiring harness...