How do I reduce TupletNumber padding?

[James Lowe]

Hello,

Here is my small example (I have also attached a .png file).

--

\version "2.13.37"

\relative c'' {
   \time 2/4
   \key c \major
   \override TupletBracket #'bracket-visibility = ##f
   \override TupletNumber #'font-size = #-3
   \tupletDown

   \partial 4
   \times 2/3 {
     g16\>( a
     \set stemRightBeamCount = #1
     g\!)
     \set stemLeftBeamCount = #1
   }
   e-. a-.
}

---

I am trying to get the tuplet number much closer to the notes than it is 
currently, but I cannot seem to find which parameter to change.

I tried

   \override TupletNumber #'staff-padding = #-3

and

   \override Score.TupletNumber #'outside-staff-priority = ##f

But to be honest I struggle with the IR and how to work out when to use 
a \override xxx.yyy #'ZZZ = ##123 and \override xxx #'YYY = ##123 and 
for which grobs :(

Thanks for any help.

James

grab.png
Description: grab.png