Ok, I don't think we were looking at it the same way. I tend to isolate the factor being discussed and let all else remain the same. If you were at agressive throttle pulling a trailer, you most likely will NOT hit boost sooner in the RPM range than if you were not pulling the trailer. The driveline load does not matter since under WOT the engine is at it's most efficient (moving the most molecules).
Now, using Ken's scenario, let's assume RPMs do not change. Throttle positon does change due to the cruise control input. This increases gas input which increases exhaust density and will spin the turbo creating more boost than it was when it was just cruising along on the flat surface. I guess what I am saying is that if the boost is mapped out on a dyno and it hits Xpsi boost at XXXXrpm, adding a trailer is not going to change those numbers because on the dyno the engine was stressed up by being taken to WOT. The engine would be at it's threshold with or without the extra load.
So, my point is that if you are moving along, a change other than additional driveline load has to occur to reach more boost. Simply loading the engine doesn't do it, as in Ken's example more throttle (and more gas) is required and boost does increase.
I do have some experience with turbos since we have 2 turbo diesels for the farm. Both a powerstroke and a duramax. But I think this was more of misunderstanding or incomplete explanation than being right or wrong.
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