Ok, this may not be your answer but I ran across this and it may help someone.
Cold start, both t-stats closed, coolant pumps to oil filter-flywheel houseing cross over-block-heads-EGR and heater core @ 26GPM. Engines warms to 180* first stage of the primary t-stat allowing some flow to the radiator. At 185* secondary t-stat starts to open flowing more to the radiator. In here @ arond 132* the turbo starts recieveing coolant through a thermo controlled circuit by-pass. At 203* the primary stat is full open. At 212* the seconday stat is full open, all coolant is through radiator and flow is near 80 GPM. Now this is for the LLY engine. bob.............