Assassin grill question

[TrevorW]

I've recently acquired a 36" assassin grill and was wondering how many lit coals to start with to get the grill up to temp for smoking? I'm use to a weber kettle and using a sns starting with about 8 coals. The assassin I use a v pan and snake method 3 wide 2 high and about 12 lit coals and it takes forever to hit 250. Just wondering how others do it. Thanks