studing dyno sheets

[mauve66]

looking at dyno sheets from 2008 mopar muscle engine challenge and i had a question of you engine gurus out there...........

every one of those engines (winner had 758HP/601TQ, it did rev to 7K rpm though ) had the torque drop off from about 3600 rpm through 4300 rpm before it started picking back up

do you think this is a result of them using a single plane manifold??

i always thought the torque curve should be a gradual radius instead of a roller coaster??