I don't think there is much emperical evidence for the 4D torus - it's rather one of a number of possibilities.
Einstein came up with what are now called the Einstein Field Equations but never solved them they describe the shape of the Universe.
http://en.wikipedia.o...stein_field_equations
There are a number of solutions which give different geometries
So it is one thing to see what geometries are possible - quite another to derive a test to see which of the possible solutions is in fact the case.
This is similar to where we are with string theory
The fact that it has been so long without evidence is mostly to do with the experimental difficulties in the sizes involved we are talking about 10to the power -34 meters here - 1/100,000,000,000,000 the size of an atom.
There are good reasons for thinking that the current model is not the final story - everything seems to work in sets of 3 and there is a definate pattern. This implies an underlying structure in the same way that the periodic table implied the current model that Gell-Mann came up with.
Truth is we are at a stage in physics where the theories are often self-consistant and explain what we already know but that direct observations to confirm them are beyond or are at the limit of our technology
Indeed in some cases they may be beyond any technology.
Other examples include gravitational waves and the multiverse