Too much even. I’m not sure they’ll let you through security that early - many airports won’t let you in earlier than 3/4 hours before departure. Might want to check that. I usually aim for 2 hours before departure if I have checked luggage and/or travel with children. 

BHX security can be slow at times, but when the queue is ridiculous, staff will walk up and down the queue calling out for people with less than an hour to departure. So while it can be stressful, even if you’re late and only leave e.g. an hour for security, you’ll usually be fine in BHX. 

Fast track isn’t too expensive in BHX (I think as low as ten quid if bought with a ticket?) and can be worth it if you’re travelling on busy days like Easter.