Blyton Track Day??

[turbonutter]

What is the flow rate of your coolant pump? Maybe it's a brain fart on my part but your figures show a 7 times over pressure drop on a 10 litre/min flow change?

No idea what the flow rate of the system is, I have the Alfa mechanical pump, plus a Stewart components booster pump. The electric pump is rated at upto 55GPM, but I assume that is free flow & they dont publish a graph...
Below is the flow graph from the Laminova site - considering there is a pretty big hole in the middle of the cooler, there is quite a pressure drop with no restricter....

I will be doing some measuring and calculating before i decide to install a plug or not....