Ballast resistors

You can buy a coil that doesn't need a resistor all day long.

Yes you can, but it will not come even close to the output of this new coil from Andover. There's a lot more to getting output than simply buying a coil with a built in resistence.
The components in the ECU that give you a performance ignition system that can achieve high RPM, Hold Timing Events, Maintain High outputs and give you excellent service life.

We have tested over 40 different combinations of coils, some off the shelf and many custom wound with various specifications to come up with this coil.

It's been engineered to operate to max output and high RPM to match our ECU.