I jumped into a T-38 with a J85-15 engine and made this video and then plotted the time it took to accelerate from IDLE (50%) to Mil (100%) and the plot is basically an exponential acceleration. The Simulation is more like a linear (almost logarithmic?) plot? See attached graph and Click here for video: https://drive.google.com/file/d/1AD41lx5o3xUNdS5e_6Q5it5wrbLSCrrJ/view?usp=sharing
Once the %RPM is 80% or greater, the engine response is INSTANTANEOUS!
The graph (below) is the time is takes to go from IDLE(50%) to 55% = 1 sec, then 0.66 sec to reach 60% (from 55%), etc... Total time from IDLE-to-100% = 3.29 Seconds.
