Style chooser

hi all car expert!!
just wanna ask, is it up boost our car equal o up our car's power?
can any1 explain it more detail?
if really do so can up power,then why people still need others mod?
if gsr up boost to 1.0 then roughly how many HP will i get?
is this oso help to increase the top speed?
will this affect our engine?will overload our engine?
really appreciate of your ans..thanks very much!!!!