It depends. Every RNG in G4 varies in time because of delay. The higher your delay, the longer the RNG abuse will actually take. But usually it depends on how fast you can hit your target delay, and since this is your first G4 abuse (Right?) it might take a while.
But with the proper tools (Like the amazing EonTimer!) it shouldn't take long to hit your delay! I've taught 2 people G4 ID/SID abuse and it was their first time doing G4 RNG, and they got it :) I haven't seen them around lately, though.