EMS4 works fine with my VVT, but the whole shebang came from trackspeed and all I've every touched were the offset when my cam trigger wheel slipped (seems to be an auto-x problem) and the actual table. The control function was spot on. Now the other parts of the EMS4... well lets just say the megasquirt is where the smart money is unless you're going to make tuning it someone elses problem.