hello fabio.

i added 1 section on my track.. and also i adjusted the last 2 suspersion arms from the rear to lower down the rear of the tank.
about your idler problem, remove your tracks and check your idler if its properly aline or pointing inward.. by idler probem is that they are pointing inward thats why my track keep on coming off during sharp trn.. what i did is i remove my tensioner and added a plastic plate on the rear inside part inbtwn the tensioner and the hull.. it'll streighten up your idler or will point a lil outward whch will prevent you track to come off while in sharp trns..
thats what i did to my tank...

freddi's tank i think he added some tape or something.... freddi wanna add some solution to prevent the track from coming off from the idler..

hope this help fabio..

daryl