i concur with barit1,
over 20 years test cell testing of mainly cfm56-3c1's shows the extent of thermal growth of the rotating group which of course is predominantly the high pressure turbine disc creates around a 20 deg c egt reduction upon a second transient accel to temp rated take off.
was oboard an aircraft around ten years ago and the pilot took the 737-400 to take off within about 40 sec's of acheiving min idle...i felt like yelling at him, lol.
more importantly, if the engine in question is only running at 22k (3b2 rating) she's getting pretty tired and the decision makers should stop penny pinching and get it off.
have only recently stumbled upon this site and as stated above, 20 years testing, 30 years in the game until a year ago, thoroughly enjoyed it and have no intention of turning my brain off.....i took great pleasure in exhaustive study to gain a complete understanding of the cfm56-3 main engine control and other engine systems and am more than happy to offer input if required.
safe flying to all, cell dude.