The 12V-10A accessory fans marketed on EBay as "electric superchargers".
For those less mathematically inclined, a belt-driven supercharger is said to take 10HP to drive, for sake of argument.
One HP electrical is 746 watts. 12V*10A is 120 watts, or 0.16HP.
About 1/62 the needed HP.
Then, there's the squirrel-cage fan, a design not known for being able to pressurize air much.