can somebody please expain what sort of pressure's i should be seeing though the gears and revs.

i am geting -20 on tick over, I only get + boost when accelerating and full boost when foot down.

is this right?

 

With regards to the particular readings that depends on the boost gauge, but you will always have negative boost at idle and usually light throttle as well. Full boost is obtained when the lead foot is to the floor, and positive boost is when you are accelerating.

So yes, that is right, nothing to worry about.