Not an engineer, but my guess is that having more than 6 cars would not allow them to do some of the maneuvers Schilke wants. I would think that the geometry of first drops and the like would have to change somewhat significantly to allow a 7 or 8 car train.Is there a reason why RMC seem to only do 6 car trains? Off the top of my head I can't think of any of their coasters that have more/less.