Take it to mainstream performance and let them tune it on the dyno. You will not see any noticeable gains by "playing" with it yourself. You will however fuck your shit up very badly if you change the fuel tables and lean it out. Or you will burn the shit out of some expensive ass gas and foul out plugs and start skipping by making it too rich. As far as you setting your VTEC crossover to 4k rpm's that's the stupidest fucking thing I've ever heard. Don't play with shit if you don't know how it works. Take it to someone who does and you might actually get your money's worth out of it. I seriously doubt it though.