the car itself ona decent quality psu consumes around 40-90watts, then add everything else which is around 140 on full load. if the psu is cheap 10 buck's or so ud end up exploding your system.
the power supply unit would start throttling at 25C or even 20s and ur screwed.
to be safe for a very low end system 430w reputable 80+/80+ bronze of entry level for heavier consumption is required if not 550w's. u could cheaply aim for the XFX 430-550w XXB9 or X2B9 etc. that might do the job for you.
but i warn you.. the unit's might get so load in load or be still even on an idle because of the rifle bearing fans running at a high RPM due the power supply architecture and wattages/voltage's efficiency.