I have this unchecked, the fsx setting, engine stress causes damage. To get the service based failures with the ngx to work correctly, is this supposed to be checked or unchecked?

In the FSX settings window you'll see "Aircraft Stress causes damage" [Not engine stress causes damage].

 

This essentially allows FSX to render the "CRASH" show-stopper event when you exceed VNE [Never-Exceed Speed, or in FSX' case, overspeed] or a set G force limit. Currently the NGX does not simulate engine damage based on excessive N1/N2/EGT, or water ingestion.

 

It should be noted that if you hold down F4 and keep the engines above 120% N1 indefinitely, with "Aircraft Stress Causes Damage" disengaged, you will encounter some pretty interesting quirks of the NGX. For instance, holding down F4 and rocketing across the sky above VNE will actually cause the rudder to reverse! Applying left rudder will turn the aircraft's rudder to the right, and vice verse. You'll also notice the EGT reset to 000 at around 121.7 N1.

 

Just a couple'a fun facts.

Apparently, you do not own Acceleration

 

But to the topic matter, unfortunately I have no idea.

Apparently, you do not own Acceleration

 

But to the topic matter, unfortunately I have no idea.

 

Oops! You're right, I don't have acceleration, so I was completely unaware of that setting. Since I gave wrong information in my post above, I went and looked up the answer to your question in the manuals. In the aircraft Introduction PFD [Page 18], the NGX manual states:

 

Pay particularly close attention to the settings displayed in the graphic

below. All of the boxes in the ENGINES and FLIGHT CONTROLS

window should be cleared if they are checked:

 

So it looks like the manual suggests keeping the engine stress causes damage box unchecked.

RTFM...copy. Thanks gents