[Rogue_Ant]

While it is true that the stock coil will work just fine for many applications, that does not mean the system cannot be improved...

On bigger hp 951, especially those running E85, coil energy does become an issue. This can easily be seen by the necessity to run smaller and smaller spark plug gaps.
On a 944NA, finding power is going to be tough.

That said, there are other benefits of a more powerful ignition system. More spark energy can mean the ability to run larger gaps, and having a longer spark duration. The second-order effects here can relate to emissions, economy, and combustion reliability.

The misnomer is thinking of an ignition event in the combustion chamber as a static process. It is not static, rather it is highly dynamic (even more so in a turbo car than NA).