It cost GN particle based on your mass and your setting of acceleration(called "Max Overload"), while 1 stands for 10m/s^2, so 1t mass accelerated by 1m/s^2 cost 1 unit. Since Taudrive only hold 50000 unit GN particle, it is only enough for 100t vessel cancel gravity (equals to 10m/s^2 acceleration)for 50s. So, if your vessel is very heavy, yes, it could happen. BTW, 400EC/s is only enough for a 40t vessel get 10m/s^2 infinite acceleration, which is quite limited... If you really want it become some kind of imba engine. you could modified the fuelefficiency in your CFG file of Tauengine, smaller the number, stronger the engine.