the pumps are is a "push/pull"config.
setup:
bayres - MCP600 - heatercore - BIX - MCP600 - double heatercore - WiteWater - (splitting loop) one to the Z-Chip, one to the GPU, back to bayres. So the bayres has 2 in and one out (to MCP)
The speed of the water is good with 2 pumps, I can see it clearly speeding up, so I guess 3 rad's makes it a restrictive setup., giving with a second pump a 2lpm gain.
The little gain could indeed be that it only gives me 0.5 degree extra...
Hmmm... bommer
As I'm still not even close to the 11 lmp that the pump is capable of in free run, there is no use to place them in paralell. I guess placing the BIX and the heatercore in paralell could do some good, making the setup less restrictive.
One thing not so clear to me: I was guessing that my tygon 1/2"would feel solid with all this pressure, but is't not. I still can squeeze it to flat without problems...
well I guess I need to redo some of the plumming work
Thanks for the input!