I agree with extremesledder, it won't make a difference. I built and raced turbocharged vehicles for a long time and the less back pressure after the turbo the better.
Think of those big, old water wheels. There's always a small pipe with fast flowing water to make it turn, but there's a large river after it to not impede it's rotation. The turbine wheel works on the same principle...high velocity in, low restriction out.