I'm QUITE confident that 400WHP is possible without the bottle. By my conservative estimate a 185mm Pulley, Custom ECU Tune, Rear Cats and Resonator Removed, NeedsWings Intake, LET HE and Pump, Isolated Intercooler tank, Thermostat, Plugs, Wires, Meth Injection should easily do it. I'm thinking 410-420 on that setup.