Since SKI gives you lambda calculus, and the lambda calculus is turing complete, you might win that way. :)
C++ templates are.
Check out this IOCCC entry which does simulate a Turing machine, but only by having another script repeatedly run it.
Edit: Yes, I meant to copy the link, see mchouza's comment for the link.
I think you mean "the minimum to get a Turing Machine", which is not the same. But I am being pedantic. Very, very pedantic. As befits the topic. :)
My first attempt shows Ruby simulating a cyclic tag system with only 15 unique characters including newlines and spaces: https://github.com/elitheeli/oddities/raw/master/only_a_few_...
EDIT: down to 14 characters.
Sure, but it counts regardless of what you're talking about. We don't generally talk about charging data against the TM because they all need data of some sort to do anything interesting. "eval" still gets you there. (Pedantic.)