Allways possible i mixed up some calculation.
Here you can see what actually happens.
Cant read Code while Melting
I Think i found the Problem tho. The Gt Net seems to take the right amount. If you let the EnergyCell set to 800 rt/t Maximun Output it seems to Dump 400/rf in the Transformer, which it doesnt need, but if you Limit the output to 240 rf/t which is the amount it needs for Running the 120 eu/t Recipe (again 2:1 Ratio Config) it works Just fine and you get roughly the correct Total Rf Transfer of 400000 Rf + Loss that you would expect.
So Thermal Expansions Fault? Gt Transformer says "Give me the Powers" and Energy Cell says "Here take all of it" ?
Dont know much about how the different Energy Networks work and my current Coding knowledge is mediocre at best..so im just guessing here
tl;dr : Limit the EnergyCell output to what the GT Machine actually Needs