Hello!

I have a question regarding EPR setting during climb and cruise.
What setting is supposed to be used?

I have tried to help myself, but haven't found anything in 707perf.zip available at Avsim. I also looked through the manuals provided by Captain Sim but all I could find was different EPR settings for take-off.

Thanks in Advance!

They used "rated thust" for climb. You may be able to find takeoff and rated thrust settings for free on the web, but you will have a hard time finding cruise charts.  I have bought a few manuals and still don't have any, but I have found some fuel consumuption charts for cruise and have been using those to derive EPR settings from DC-8 cruise charts.

Anyway, even if you have the charts, you need a reworked EPR gauge and flight model for the cruise power settings to work.

Hm.. using AFSD, I discovered that the EPR gauges are displaying higher values than the actual EPR being calculated by FSX.

Is this error true, or am I wrong?

That would simply mean that Captain Sim has used a custom EPR gauge as the default FSX values for EPR are not accurate.

Thing is, the fsx values are more close to the values listed in the documents available at avsim.

You can make a gauge (it's not that easy however) that will show the default values, if that's what you want, although they will still be far from accurate.  I have made a custom one that displays values that properly correspond to the displayed N1, but it still needs more work at the lower end of the scale where I don't have much data.

I have however, encountered a problem with the way the gauges are designed with this aircraft, which has been done to improve performance.  With a custom gauge, I can only get an EPR value for a single engine to display on all four gauges.  Another problem is you can't control or get rid of the Captain Sim coded needle.  Even if you eliminate the texture you have a black polygon needle still floating about and the texture is also used and therefore needed by numerous other gauges.  So I ended up with two needles  on the EPR gauges (I put stripes on the accurate one) and I have to use a single throttle lever for all four engines.

I would like to release my work at some point with power setting tables, but it won't be any time soon as I don't have the time right now.

Don't worry, Michael, you have another baby (pun intended!) in the pipeline there and I'm once again wishing you all the best there.
The 707 is very able to fly right now and, although your tuning would be very appreciated, there are other things among live which have a high priority for good reason.  :)
So no need to hurry there in any way.