That great youtube channel "Engineering Explained" ran a test of temps in the engine bay. His purpose was not FE, but the test is revealing for those interested in using a WAI for the reduction in pumping losses they can produce. Many of us have thought that positioning the WAI near the exhaust manifold is best. But that is apparently not necessarily where the hottest air is. Here is a screenshot of a key data reporting moment:
Here is the full vid: