I think for starters you could try some kickers on some of the "almost straight" sections between turns, this could help you gauge as to weather bigger jumps will fit.
Expect also to have to "move" sections of the track about, if a certain section doesn't work because of a corner or where you want a jump, then be prepared to get busy with the shovels and wheelbarrow.
Oh yeah, and your English is ok too
, better than some the native English who post on here
