Billet front covers have been a selling point for aftermarket converters for forever,

but do you know why we have them? Factory torque converters are notorious for growing when exposed to added pressure, often expanding to the point where the front cover pushes against the flex plate. This is called converter ballooning. A stronger, billet front cover strengthens the converter as a whole, keeping it from ballooning under higher pressure. It’s important to note, however, that even with a billet front cover in the mix the impeller can still balloon when exposed to excessive pressure. According to Sun Coast and Linco, it’s best to limit pressure to 330-psi or less in street applications.