What comes out of twin pipe?

I noticed the other day that the exhaust gasses from the two tail pipes are different. By which I mean that (when looking from the back) the output from the left pipe is much greater than that from the right hand side. The left looks normal, ie this time of year the gasses are easily seen for the first couple of minutes while the engine gets hot, and you can feel the heat and pressure of the exhaust. Whilst the right hand side appears to be putting out almost nothing.

Is this normal or something to investigate further?

Car is a 1.6 Mk 1

Thoughts?[*-)] 

Same here for a mx5Parts twin, There seems to be a easier path for the gasses to the left pipe, But if you get the exhaust good and hot then the pipes seem to balance out. Just like a chimney vents better when warm you get a drawing effect