I used to navigate/copilot a 480ci methanol powered jet sprint boat, Group-A class. It would pull just over a G accelerating, and did the 0-100kph sprint in 1.9 seconds. That boat could also do 100kph-to stop-to 180 degree turn - to 100kph the opposite direction in about three seconds. (This is something unique to jetsprint boats, they can pirouette like nothing I've ever experienced). That pulled insane G's, so much so that you needed the HANS device around your neck to stop the weight of your helmet breaking your neck.

Imagine having to strap into a HANS device to drive a road car. I want this future.

For those that are unaware, all rockets then rapidly increase their G. For example the Saturn V had 1.20 g at takeoff but climed up to 4-ish: http://www.braeunig.us/apollo/saturnV.htm

Someone on the Saturn V started experiencing more G than the Roadster about a minute into the launch.

When you move a building-sized fuel tank under its own thrust it's going to start off slow, but accelerate as more fuel is burned.

Plus I'd expect thrust to be kept low until clearing the lower atmosphere so it's not all lost on drag.

So your body experiences 1.44 g horizontal plus 1 g vertical, giving total 1.75 g. Is that right?