I am purchasing wire shelving for an 8 foot wide concrete wall laundry. I will hang two 8 foot by 16 inches. Are 4 vertical wall brackets enough to support it? I understand I should space them every 24 inches. Is this correct? Do I really need the Hang Track, since I will be attaching the wall brackets with Tapcom 1 ¾” screws?
I would say it all depends on how much weight you plan to put on the shelves.
Here are some "specs" on a site for Closet Maid Maximun hold 6' x 16" shelving.
Holds up to 600 lb. per shelf (total weight per 40 in. track not to exceed 900 lb.)
Weight should be distributed evenly across shelf.
Can be used with maximum load installation hardware (sold separately)
Installation in studs or concrete with standards and brackets (sold separately) no more than 16 in. apart
Wire shelving is very flexible. For that reason, and regardless of your intended loading, I'd go every 16 inches with support.
As has been said, you don't need hang track. I consider that useful for those who like to reconfigure shelving arrangements on occasion, such as in a walk-in bedroom closet. Otherwise they're cumbersome and wasteful.
I like to put wall clips every 16" and at the very ends, and I hit every stud with an angle bracket. You'll still get flex between supports with concentrated loads, but for general use you'll have a decent setup.
What brand is this, "ClosetMaid"? (I'm guessing based on the first thing that comes up when searching for "Hang track" that looks like it's related to wire shelving.)
That appears to be something intended to allow hanging standards (the upright rail parts) between studs, and to help folks that can't use a level to line up the standards get the standards lined up (of course, if they can't use a level, no bets on them being lined up level, but they seem to think it will somehow magically happen if they just spend more money on that part.)
You don't need them.
With a concrete wall (no studs to find) and an 8 foot shelf, I would not stick to 24" spacing unless some other aspect of the shelf system requires it - the end brackets can be in somewhat from the extreme ends and still support the shelf, unless you want to store anvils at the very ends of the shelves.