Calculations over at NSF made it clear that SN8 had sufficient delta-v on the pad to reach the Karman line, if they hadn't throttled back and turned off engines

Calculations over at NSF made it clear that SN8 had sufficient delta-v on the pad to reach the Karman line, if they hadn't throttled back and turned off engines as it ascended. So SN8 could already have reached space. (With the assumption that the nose could have taken the pressure of going supersonic relatively low.) Similar calculations state that a Starship with full tanks and 6 or 7 engines might just be able to make it into orbit on it's own, assuming it doesn't have any payload or heatshield. Since that's useless and wastes the ship, they will never do it. But it still boggles the mind that they are using a craft that is almost a SSTO ship ... as a second stage, on top of a massive first stage. The Raptor engines are freakishly good, near the top in both efficiency and thrust.