pretty much… vvti just adjusts the ignition timing over a period of time depending on who is driving the car / how the car is driven over a period of time… its basicly for a family car that is driven by mommy daddy and their 17 year old son who has a lead foot.
vvtLi = variable valve timing and LIFT! = Lift is the same concept as vtek. but unfortunately only on one toyota motor that I know of 