The rail (which is one ignition coil per every two spark plugs, so three ignition coils total) is already putting out a much hotter spark than is required to reliably ignite the fuel. Older model cars could benefit by hotter sparks and aftermarket ignitions but the current batch of TJs have, really, some pretty good ignition systems right from the factory. It has to so it can reliably pass the smog tests for no less than five years as mandated by the Feds. If I were you, I wouldn't waste my money looking for a better ignition, you'll get better returns from your money if put elsewhere.