Old vs. New, whats the difference?

[ISX]

This has been on my mind ever since AH64 mentioned it. He said the P7100 can do 18,855psi and the vp44 can do 17,400psi and the cp3 can do 23,106psi. I can't find the chart he just posted somewhere but it showed that the rail pressure in the CR engines is highly variable. Seemed to go up with RPM and load, which I think the same happens with the ppump and vp trucks and I don't see those pressures being that different. I mean 23,000 is 5,000 more but can that much have that big of difference? And when it is not at peak load/rpm, is it possible that the pressures of all 3 trucks could be the same? This makes me think how emissions is accomplished. I have heard a lot about the pressures and how the new trucks inject up to whatever number of injections per cycle, but now I don't see how thats any different from any other truck. I realize the newer CR's have multiple injection "events" which allow for a smoother powerband and quieter engine, but if you took that away, what would the difference between the trucks be? I know timing is a big factor.. But if you somehow got the map for the CR trucks on timing into the VP trucks, and canceled the multiple injection events on the CR, would the 2 trucks then sound identical? Now one other thing is that the CR has whatever pressure in the rail for the duration, whereas the VP and PPump would increase pressure quickly as the plunger rammed the fuel out. I am not sure if this makes any difference or not in performance though. And do you have any info on the VE pump?