As a long time engine mechanic let me throw my 2 cents in. Have you heard a v10 or 12? There is a difference in it and a v8. Or a 2cylinder 4 stroke v twin. The exhaust pulse from each of these engines is quite different. I compare it to a flap of cardboard in a bicycle spoke wheel. Remember this we did when kids? If you had a wheel with 2 spokes and one with 6 spokes and one with 8 spokes and one with 10 spokes. All turning the same speed. The sound and volume of the clicking spokes with each wheel is very different. Then in a car you have to consider the design diameter and length of the exhaust tubes and any bends they make as well as the design of the exhaust manifolds. In addition the shape of the cylinder and exhaust ports and volume of them. That's why 2 different design manufacturer v8 engines in 2 different cars with the same exhaust setup can sound so different.