CoolP wrote on Nov 15^th, 2011 at 5:37am:

It may be that you are seeing the outcome of the sort of reversed engine model on the 757. The real engine would have a slow spool up at low N-values, whereas the sim gives you an almost instant response. On the other side of the spectrum, the real engines are fast if you already have some 'rpm' on them, but that's where the 757 begins to slow down severely. I could see her 'hitting a wall' at TO well below the commanded EPR value, but then very slowly advancing to a somehow usable value.

So what do you think i should do because no matter what she wont go past 1.66EPR at all even though the commanded thrust is set for 1.79 and when i derate to 1.76 or any other value higher then 1.66 EPR it wont go any higher then that. now i want to know is is there a fix for this and is there any modifications out there that would help me. thanks so much for the response.