There are, but Stealth can't be as it isn't the right type of accelerator, also it would have to break before doing a loop becuase the G-Force would be too strong if it was going through a standard loop at 70+mph.
4?If you move half the distance to the door each time, that means that 8 divided by 2 is 4, then 4 divided by 2 is 2 and then half again, is 1 and then you can touch the door.
People, cut the Admins some slack! they went through all this trouble to do this to make the forums a nicer and better themed place, yes it will take some getting used to and it is a little slow but otherwise the admins have done an awesome job!