lmao yes there is, do a neutral slide spin then activate death tornado while in the air, you'll get the speed boost when you land
if you start mock tornado without jumping out of NSS (while sliding across pits, etc) you'll keep the speed even if you jump afterwards
idk what mach tornado has to do with the z axis tbh, unless nsane trilogy swapped y & z axes? it works nearly the same, but i'm also not trying to replicate it perfectly, that's why i call it the mock tornado
man i gotta get to work on that speedtech vid