Looks very close to my graphs on the 1.8T when I played with VVT all day ha.. I was able to get it to spool 2-300 rpm earlier, but seemed to have trouble keeping the same boost right after the switchover with the early spool settings. Timing was the same at the switchover point. Ran out of time. Nice to see an actual dyno graph as opposed to logz. I'll try and get my graph up.

My switchover point was right at about 4k as well. I was surprised how well it worked right at the best switchover point, but how only going a little away in either direction screwed it all up. Do you have any before/after's with it optimized? IE not just all on, all off? I'm curious to see if you have the same issue after the switchover point.

Seen very similar on my dyno.  Engine load also follows a similar profile for those without:)

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As others have said, neat 

I've noticed that with all cam phasing, there's always a 'bounce' when you get to the end of the advance.

I presume it's some form of compensation for the pulse harmonics coming out of a dynamic/shifting phase into a stop. However, do you happen to have a more detailed explanation of exactly why this is done?

Ahh, that's your AFR, not your valve timing. Gotcha.

And I should revise my question, the 'bounce' I'm referring to isn't happening when the cam reaches the end of adjustment, it occurs at the manifold changeover. Although I still suspect the reason for the brief increase in cam timing is to compensate for change in harmonics due to the runner length changing. 

To illustrate, note how both the 3.0 and 4.2 engines have the cam timing pick back up briefly at about 4200 RPM when the runner lengths change.

I also assume that if you change your intake changeover point, that you'd have to move that jump in the cam timing to whatever point you are doing the changeover on the runner lengths.

That said, I don't know that there would be any point to changing the manifold changeover as my understanding is that the benefit that you get from harmonics is a direct function of the runner length and largely independent of any other hardware changes such as intake or exhaust correct?

So in other words, unless you change the length of the runners, you shouldn't touch the manifold changeover points right?

Yeah, I don't know that there would be much to be gained by fiddling with the runner changeover.

The only way I could see the harmonics changing is if there was a change in the upstream (i.e. intake end) pressure.

When I think about it, the speed at which a pressure wave travels is limited to the speed of sound IIRC. Now, if you assume that the pressure wave generated when the valves shut is travelling at that speed (and I don't know if it does, I'm just speculating), then there will be an optimum distance for it to travel in order to meet the low pressure area at the beginning of the intake where it reflects back towards the intake as a result of meeting the next incoming pulse in order for it to be timed right to assist that incoming pulse into the cylinder.

However, what could change things a bit is if the incoming air was being drawn in at a higher velocity or volume via a better intake. I would think that if that were to be the case, then the pulse would begin to reflect back towards the intake valve at a different area in the runner/manifold wouldn't you think?

In that case, you'd also probably have to play with the cam timing a bit too.

Problem is, if you did it on a dyno with a N/A engine, you'd probably have to be able to simulate the air being stuffed into the airbox at up to and over 100 km/hr in order to get it right.

Oh, and I was also speculating with respect to why the cam timing kicks up a bit. When I look at my logs, there's a spike and a drop in the airflow whenever the manifold position changes. It's possible that the bump in the cam timing is there to dampen any oscillations caused by the sudden change in runner length.

Thoughts?