Look kid, it's a computer game, call/email the people who made it. We can't help you here because your game doesn't behave like a real aircraft, if it did you wouldn't be having these issues.
If you want to learn the real aircraft systems I'll suggest you buy yourself an FCTM and FCOM or some systems manuals, they're easily obtainable on ebay and go for $20. Reality is that you won't find any aircraft simulator (even $100,000+ FTDs) which behave exactly like a real aircraft.
PS. I mean variance in frequency output based on engine speed, even a CSD has a delay in response.