CoolIP is correct. The only stuff I have found on the net so far (that you don't have to pay for) is Matt Zogren's stuff which is at AVSIM. I have a copy of it and supplemented this with some material on the 707 from the Boeing website. I just worry about fuel flow and not so much about EPR as I have no idea what is precisely the engine version Capt Sim used as a base model for the engine algorithims. There are various engines with different cowl configurations so one size does not generally fit all if your after exact precision but they are all in the end about the same and I can live with the differences. Just keep the engine needles out the red zones and your right and the rest depends on the day you fly and what the outside air temps are where your flying or intending to fly and then go for the expected fuel burn per engine from the Zogren tables (which came from Boeing anyway).