I was wondering if there is a real difference (for wake size I mean) between a boat with a central engine and a boat with a rear engine.

With no other weight in the boat, yes. You can mimic the effects of the rear engine (v-drive) by adding additional weight in a central engine (Direct Drive) boat. you also get alot more room in a v-drive. Correct me if i'm wrogn but don't most manfacturers use the same hull for their DD and V-drive boats

Adam you are correct in that most manufactures use the same hulls for both

Thancks guy ! this help me a lot.