if I want to change my vtec crossover point at what rpm is it the best?
my mods are: CAI, 2.5" custom exhaust, microtech EMS, removed dual stage intake butterflys.

I currently have it at 4000 rpm

 

In my opinion your mods are too light to warrant a drop in the VTEC crossover point as low as you have it. With that setup why not try 5k rpm. I personally would keep it at stock. I've said it before, and I'll say it again. Honda knows what they're doing. They put it where they did because they did exhaustive testing and retesting. If you want to lower it, that's all fine but I think down to 4k rpm is a little too low. My $0.02

 

keep it at 5k...and why'd you take of the second stage intake butterflies?

Also, 2.5" is too wide for a N/A honda..i hope you're going FI