I'm not familiar with the 'Greddy' brand but I know that the Seventh Generation(2000-2006) Toyota Celica GT-S has 191 horse power and a typical supercharger can produce anywhere from 25 to 125 horse power, it all depends on if you upgrade the cooling system along with the supercharger. And by the way, your mileage will go down the toilet along with your warranty(if you have one), but I'm assuming you don't care about that. Hope this helps.
en.wikipedia.org