At my son’s private prep school, Vandy & Rice have zero rejections at ACT 35/36 and GPA>3.9. 100% rejections at 33 and below. Caltech is not for everyone, but they do have an admission process that will take an intensely science oriented student at an ACT of 33+. I know of several students who were rejected at HYPSM but admitted to Caltech.
None of these schools seem to care much about race either. At Caltech, Asian males are the most common group. Vandy and Rice have some of everyone. They all want very smart kids.