I think this video is probably an appropriate indicator of WAP5's acceleration with 24 coaches.
The videographer is on-board 12480 Bandra-Jodhpur Suryanagari Express (24 coach superfast) led by BRC WAP5 30048 (AMUL). There is a speed restriction of about 15 km/h due to maintenance works.
P5 starts accelerating at 0:51 after clearing the speed restriction. There are two trains lined up - one after another at some noticeable distance.