you may want to check your oil screen in the solenoid, also it may be mental. The butt dyno is never correct... Anyhow, there is no other way to make vtec more efficient besides move the point up depending on how high you rev and also, the cam and other things... The best thing to do when tuning a vtec motor on a dyno with some type of tuning device better than a vafc is to move the vtec point up until the vtec engagement is practically smooth with the rest of the curve, this way you are getting the most before the curve and after the curve that there is possible.