Just curious if most tuners tweak the air/fuel ratios and ignition timing and call it a day. Or if some dig a little deeper and maybe adjust the cam phasing settings also.

 

The VarioCam system is basically an on/off system where at a certain rpm the cam timing advances a set amountand at another rpm it reverts to the non -advanced timing, so there is not much opportunity to adjust this. The VarioCamPlus system found on the 2002+, 3.6 and newer engines is mush more complex. His system allows for a variable amount of advance to the timing and also varies the lift of the intake valves. So with this systems, in theory there is more opportunity to modify how the system works.

That being said I don't know how different tuners have taken advantage of the newer system. If you are interested I have some writes ups by Porsche that show how the systems work and the differences.

 

I would think just the A/F ratio leaner & allow the DME to continue to retard ignition timing when needed.

 

I would like to know this also my car has a pretty abrupt change around 3100 rpm if that were moved around or smoothed out it would be nicer overall.

 

I play with is all the time.. It easy to create big holes in the power band when doing this, especially with a n engine that has stock internals. I only see gains from this where we alter port flow, CR, and displacement. At times we have to alter the system to increase drivability, since VVT changeover can become so radical that the car is no fun to drive. I detune the system more often than anything.