What is this bracket called

That is the front frame gusset, and if you look at the overall picture, it structurally supports where the firewall and kick panel side come together. That is an area that is also gusseted with a torque box on some higher performance models. It’s an important area, I would leave it in.
Understandable Being its a racecar im going to supplement the part with a piece of 1 5/8" chromoly tubing as its not available as a replacement