Build Log: 100,000 PPD by 1/23/2011

[onex]

found you this:

this site is like the TFT-Central for water cooling,
you can see in the graph that these huge rad's might be the culprit which takes the pressure down,
the 3 radiators shown differ in the pressure drop when the GPM count goes up,
the author reffers to the fact that adding another one of these MCR220's (or any other for that matter) would lift the drop rate at up to 2 times (or a bit less as the GPM drops the resistance would drop either).
differences between radiators could be due to the curving angle of the coils, the size the fluid has to go through, the material used and it's resistance and (can't remember that word) but the actual quality of friction factor from the inside.
maybe even the substance that is being used and it's thickness.
there are ways and tools to check these drops,
link to the article:
http://martin.skinneelabs.com/Swifte...20-Review.html

that probably should be the main issue burden on these pumps

E:
just seen you actually kind of solved it!