As Todd was talking about above.... air temp and humidity play a big part in it. SO... DO NOT tune your acc delay to the edge on a cool day. You may wind up with a flame out when it's hotter outside. Also... if you try to get your value too low (as it sounds throaty) you are actually pushing flames deeper into the NGV and turbine wheel. This will erode the parts faster... and can lead to cooking oil into the hot-side bearing.

I'm not saying to not change things as needed... but the slower spool-up on some of these engines is for safety. the more modern designs are simply more efficient and can spool quicker.

Just my 2 cents... take it for what it's worth.