So I took the posted specs of a quality electric supercharger (http://www.aeristech.co.uk/electric-supercharger/) - specifically a PR of 2 and .07kg/s flow rate and ran it through a program called RPA (http://propulsion-analysis.com) combusting the air with kerosene at ~14:1 afr (much higher than a typical jet engine) and got an abysmal performance figure of <15lbs thrust. given that the compressor & electric motor combo itself weighs nearly 10lbs makes it untenable. Never mind that it would take around 50lbs of lithium ion cells to power the thing for 30 minutes. Taking just the compressor specs for Garrett's largest turbo (ignoring how it would even be powered) - PR of 5 and 2lbs/sec would produce ~330lbs of thrust, and that's a HUGE turbo. So I'm quite impressed by the performance of Zapata's rig of what I presume is 4 small turbojets (in the original video - looks like 6 in the latter ones). Unfortunately I was WAY off base with what I thought would be possible using electric turbocompressors and a rocket-like thrust chamber.