well, that's a nature of a rotary engine. for that reason, it is possible to do a high speed drifting with rx-7 cars (that's include fd but it quite tricky since it has a lower gravity point compared to fc). try to drift with a level 1 turbo and no weight reduction to get yourself familiar with the car behaviour before proceed with more higher power turbo. for gear ratio, set it to either 29 or 30 from the default setting.
if your rpm meter keeps to shoot out, it is depends on your skill to control the throttle and most probably your gear ratio is too low. also ou have to identify what gear that suits for a corner and make a experiment on whatt will happen if different gear are used. i'm just giving my opinion based on my 'feel' during the drift. like dephic reason said, every driver have their own perspective, so find which one that suit you.good luck.
