That depends on a few things. Chargers put a lot of pressure on the pistons and crankshaft, but only if the car is being driven like mad. If whoever drives with the chargers in does so responsibly, you shouldn't see any manifestations of increased wear. There is a bit of a trick to this, and it's basically to rev the engine just a little higher than you'd think is necessary. Or put in another way, stay in your gears a bit longer than you'd really need to. That should keep the pressure on the pistons, crankshaft etc. low.