When you ditch the VVTI mechanism, it definitely hurts your low end power.
Im not sure how the VVTI would react if you got a cam grind either - becuase the computer would be expecting to optimise the cam angle based on the original cam. So it could possibly make things worse.
Although im not terribly sure on this, perhaps some of the altezza boys will know a bit more.
The VVTI system can alter the cam angle 60 degrees. I would imagine that when they were testing it, they would set the cam at a certain position, run it on the dyno. Alter it slightly, run it on the dyno. Do this a whole lot, and find out which cam position makes the most power at what RPM. (I suppose that is kind of obvious
)
The problem being, that as soon as you alter the cams, I would imagine all of this hard work would go out the window.
Unless you want to spend hours and hours on a dyno retuning it, as well as the Motec computer you will need to run the aftermarket VVTI adjustment.
So the VVTI is cool if you want to keep it standard, but can be a pain if you are looking for some more grunt.
It is understandable why tuners would want to bin it, I could imagine it could cause a lot of headaches.
Ahh but lets not forget its not all about peak power now
Yeah, you are right! Hmmm, how can we get lots of area under that torque curve?
A turbo charger.
Come on, you know its true!
Hehe.