well, i make several road test in my neighborhood. everything was perfect until i decided to push a little harder on the pedal! That was pretty loud! Not like a gasoline engine but still noisy enough for the neighborhood
And for turboed diesel... I think its crazy to do that! Even if the sound is descent, its too dangerous that your going to cook something under your hood! Quite sure after 5 min or so your fender, wires, and anything on the travel of exhaust area would be completly burn!